CHAPTER 51-11C WAC

WASHINGTON STATE

ENERGY CODE -COMMERCIAL

2018 EDITION

CHAPTER 51-11C WAC

ASHINGTON STATE BUILDING CODE

COUNCIL EFFECTIVE NOVEMBER 1, 2020

Copies of the State Building Codes and

complete copies of the 2018 Model Codes

may be obtained from:

Washington Association of Building Officials

Post Office Box 7310

Olympia, Washington 98507-7310

(360) 628-8669 www.wabobookstore.org

First Edition

2018 Washington State Energy Code-Commercial

Effective Nov. 1, 2020

First Printing February 2020

Second Printing April 2020

First Edition based on

WSR 19-24-040

Chapter 51-11C WAC

2018 Washington State Energy Code, i

Chapter 51-11C WAC

STATE BUILDING CODE ADOPTION AND AMENDMENT OF

THE 2018 EDITION OF THE

INTERNATIONAL ENERGY CONSERVATION CODE,

COMMERCIAL PROVISIONS

WASHINGTON STATE ENERGY CODE,

COMMERCIAL PROVISIONS

TABLE OF CONTENTS

Chapter 1 Scope and

Administration ........................... CE-1

C101 Scope and General

Requirements ................................. CE-1

C102 Alternate Materials—Method of

Construction, Design or

Insulating Systems ......................... CE-1

C103 Construction Documents ................... CE-2

C104 Inspections ........................................ CE-4

C105 Validity ............................................. CE-5

C106 Referenced Standards ........................ CE-5

C107 Fees ................................................... CE-5

C108 Stop Work Order ............................... CE-6

C109 Board of Appeals .............................. CE-6

C110 Violations .......................................... CE-6

C111 Liability ............................................. CE-6

Chapter 2 Definitions .............................. CE-7

C201 General .............................................. CE-7

C202 General Definitions ........................... CE-7

Chapter 3 General Requirements .......... CE-19

C301 Climate Zones ................................. CE-19

C302 Design Conditions ........................... CE-19

C303 Materials, Systems

and Equipment ............................. CE-19

Chapter 4 Commercial Energy

Efficiency .............................. CE-25

C401 General ............................................ CE-25

C402 Building Envelope Requirements .... CE-25

C403 Building Mechanical Systems ......... CE-40

C404 Service Water Heating..................... CE-89

C405 Electrical Power and

Lighting Systems ......................... CE-95

C406 Additional Energy

Efficiency Options ..................... CE-118

C407 Total Building Performance .......... CE-123

C408 System Commissioning ................. CE-125

C409 Energy Metering and Energy

Consumption Management ........ CE-130

C410 Refrigeration System

Requirements ............................. CE-133

C411 Solar Readiness ............................. CE-138

Chapter 5 Existing Buildings .............. CE-141

C501 General .......................................... CE-141

C502 Additions ....................................... CE-142

C503 Alterations ..................................... CE-143

C504 Repairs........................................... CE-149

C505 Change of Occupancy or Use ........ CE-149

Chapter 6 Referenced Standards ....... CE-151

2018 Washington State Energy Code ii

WASHINGTON STATE ENERGY CODE,

APPENDIX CHAPTERS

TABLE OF CONTENTS

Appendix A Default Heat Loss

Coefficients .......................... AE-3

A101 General .................................... AE-3

A101.1 Scope ................................ AE-3

A101.2 Description ........................ AE-3

A101.3 Air Films ............................ AE-3

A101.4 R-Value of Compressed

Insulation ............................... AE-3

A101.5 Building Materials ............. AE-3

A102 Ceilings .................................... AE-5

A102.1 Default U-Factors

for Ceilings ............................ AE-5

A102.2 Component Description .... AE-5

A102.2.1 Vented Attic ................. AE-5

A102.2.2 Vaulted Ceiling ............ AE-5

A102.2.3 Roof Decks .................. AE-5

A102.2.4 Metal Truss Framing ... AE-5

A102.2.5 Metal Building Roof ..... AE-7

A102.2.6 Insulation Entirely Above

Roof Deck .......................... AE-8

A103 Above Grade Walls ............... AE-12

A103.1 General ........................... AE-12

A103.2 Framing Description ....... AE-12

A103.3 Component Description .. AE-12

A103.3.1 Single Stud Wall ........ AE-12

A103.3.2 Strap Wall .................. AE-17

A103.3.3 Double Stud Wall ...... AE-17

A103.3.4 Log Wall .................... AE-17

A103.3.5 Stress Skin Panel ...... AE-17

A103.3.6 Metal Stud Walls ....... AE-17

A103.3.7 Concrete and

Masonry Walls ................. AE-17

A104 Below Grade Walls and Slabs . AE-

A104.1 General ........................... AE-28

A104.2 Component Description .. AE-28

A104.3 Insulation Description ..... AE-29

A105 Floors Over

Unconditioned Space ....... AE-29

A105.1 General ........................... AE-29

A105.2 Crawlspace Description.. AE-31

A105.3 Construction Description AE-31

A106 On-Grade Slab Floors .......... AE-31

A106.1 General ........................... AE-31

A106.2 Component Description .. AE-32

A106.3 Insulation Description ..... AE-32

A107 Default U-Factors for Doors AE-32

A107.1 Doors Without NFRC

Certification ......................... AE-32

A108 Air Infiltration ........................ AE-36

A108.1 General ........................... AE-36

Appendix B Default Internal

Load Values

and Schedules ................... AE-37

B101 General ................................... AE-37

B102 Default Tables of

Internal Loads ..................... AE-37

B103 Default Schedules .................. AE-38

Appendix C Exterior Design

Conditions ......................... AE-49

Appendix D Calculation of HVAC

Total System

Performance Ratio .................. 51

Appendix E Renewable Energy .................. 61

Appendix F Outcome-Based

Energy Budget......................... 63

2018 Washington State Energy Code iii

Margin Markings

►

Indicates where a section has

been deleted from the

requirements of the 2015 IECC

Indicates 2018 IECC language

deleted by Washington state

amendment

Indicates a change from the

requirements of the 2015 IECC

in the model code

Indicates a Washington state

amendment to the 2018 IECC

(but remains unchanged from

the 2015 WSEC language)

Indicates a change from the

2015 Washington state

amendment

Indicates that text or table has

been relocated within the code

Indicates the text or table

immediately following has

been relocated there from

elsewhere in the code.

2018 Washington State Energy Code CE-1

CHAPTER 1 [CE]

SCOPE AND ADMINISTRATION

SECTION C101

SCOPE AND GENERAL REQUIREMENTS

C101.1 Title. This code shall be known as the Washington State Energy Code, and shall be cited as such. It is

referred to herein as "this code."

C101.2 Scope. This code applies to commercial buildings and the buildings sites and associated systems and

equipment. References in this code to Group R shall include Group I-1, Condition 2 assisted living facilities

licensed by Washington state under chapter 388-78A WAC and Group I-1, Condition 2 residential treatment

facilities licensed by Washington state under Chapter 246-337 WAC. Building areas that contain Group R

sleeping units, regardless of the number of stories in height, are required to comply with the commercial

sections of the energy code.

Exception: The provisions of this code do not apply to temporary growing structures used solely for the

commercial production of horticultural plants including ornamental plants, flowers, vegetables, and fruits. A

temporary growing structure is not considered a building for the purposes of this code. However, the

installation of other than listed, portable mechanical equipment or listed, portable lighting fixtures is not

allowed.

C101.3 Intent. This code shall regulate the design and construction of buildings for the use and conservation of

energy over the life of each building. This code is intended to provide flexibility to permit the use of innovative

approaches and techniques to achieve this objective. This code is not intended to abridge safety, health or

environmental requirements contained in other applicable codes or ordinances.

C101.4 Applicability. Where, in any specific case, different sections of this code specify different materials,

methods of construction or other requirements, the most restrictive shall govern. Where there is a conflict

between a general requirement and a specific requirement, the specific requirement shall govern.

C101.4.1 Mixed residential and commercial buildings. Where a building includes both residential building

and commercial building portions, each portion shall be separately considered and meet the applicable

provisions of WSEC--Commercial Provisions or WSEC--Residential Provisions.

C101.5 Compliance. Residential buildings shall meet the provisions of WSEC--Residential Provisions.

Commercial buildings shall meet the provisions of WSEC--Commercial Provisions.

C101.5.1 Compliance materials. The code official shall be permitted to approve specific computer software,

worksheets, compliance manuals and other similar materials that meet the intent of this code.

C101.6 Appendices. Appendices A, B, C and D are included in the adoption of this code. Provisions in

appendices E and F shall not apply unless specifically adopted by the local jurisdiction.

SECTION C102

ALTERNATIVE MATERIALS, DESIGN AND METHODS

OF CONSTRUCTION AND EQUIPMENT

C102.1 General. The provisions of this code are not intended to prevent the installation of any material, or to

prohibit any design or method of construction not specifically prescribed by this code, provided that any such

alternative has been approved. An alternative material, design or method of construction shall be approved

where the code official finds that the proposed design is satisfactory and complies with the intent of the

provisions of this code, and that the material, method or work offered is, for the purpose intended, not less than

the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and

safety. Where the alternative material, design or method of construction is not approved, the code official shall

respond in writing, stating the reasons why the alternative was not approved.

CE-2 2018 Washington State Energy Code

SECTION C103

CONSTRUCTION DOCUMENTS

C103.1 General. Construction documents and other supporting data shall be submitted in one or more sets with

each application for a permit. The construction documents shall be prepared by a registered design professional

where required by the statutes of the jurisdiction in which the project is to be constructed. Where special

conditions exist, the code official is authorized to require necessary construction documents to be prepared by a

registered design professional.

Exception: The code official is authorized to waive the requirements for construction documents or other

supporting data if the code official determines they are not necessary to confirm compliance with this code.

C103.2 Information on construction documents. Construction documents shall be drawn to scale upon

suitable material. Electronic media documents are permitted to be submitted when approved by the code official.

Construction documents shall be of sufficient clarity to indicate the location, nature and extent of the work

proposed, and show in sufficient detail pertinent data and features of the building, systems and equipment as

herein governed. Details shall include, but are not limited to, as applicable:

1. Insulation materials and their R-values.

2. Fenestration U-factors and SHGCs.

3. Area-weighted U-factor and SHGC calculations.

4. Mechanical system design criteria.

5. Mechanical and service water heating system and equipment types, sizes and efficiencies.

6. Economizer description.

7. Equipment and systems controls.

8. Fan motor horsepower (hp) and controls.

9. Duct sealing, duct and pipe insulation and location.

10. Lighting fixture schedule with wattage and control narrative.

11. Location of daylight zones on floor plan.

12. Air barrier details including all air barrier boundaries and associated square foot calculations on all six

sides of the air barrier as applicable.

C103.2.1 Building thermal envelope depiction. The building’s thermal envelope shall be represented on the

construction documents.

C103.3 Examination of documents. The code official shall examine or cause to be examined the

accompanying construction documents and shall ascertain whether the construction indicated and described is

in accordance with the requirements of this code and other pertinent laws or ordinances.

C103.3.1 Approval of construction documents. When the code official issues a permit where construction

documents are required, the construction documents shall be endorsed in writing and stamped "Reviewed for

Code Compliance." Such approved construction documents shall not be changed, modified or altered

without authorization from the code official. Work shall be done in accordance with the approved construction

documents.

One set of construction documents so reviewed shall be retained by the code official. The other set shall be

returned to the applicant, kept at the site of work and shall be open to inspection by the code official or a duly

authorized representative.

C103.3.2 Previous approvals. This code shall not require changes in the construction documents,

construction or designated occupancy of a structure for which a lawful permit has been heretofore issued or

otherwise lawfully authorized, and the construction of which has been pursued in good faith within 180 days

after the effective date of this code and has not been abandoned.

C103.3.3 Phased approval. The code official shall have the authority to issue a permit for the construction of

part of an energy conservation system before the construction documents for the entire system have been

submitted or approved, provided adequate information and detailed statements have been filed complying

with all pertinent requirements of this code. The holders of such permit shall proceed at their own risk without

assurance that the permit for the entire energy conservation system will be granted.

C103.4 Amended construction documents. Changes made during construction that are not in compliance

with the approved construction documents shall be resubmitted for approval as an amended set of construction

documents.

2018 Washington State Energy Code CE-3

C103.5 Retention of construction documents. One set of approved construction documents shall be retained

by the code official for a period of not less than 180 days from date of completion of the permitted work, or as

required by state or local laws.

C103.6 Building documentation and close out submittal requirements. The construction documents shall

specify that the documents described in this section be provided to the building owner or owner’s authorized

agent within a maximum of 90 days of the date of receipt of the certificate of occupancy.

C103.6.1 Record documents. Construction documents shall be updated by the installing contractor and

architect or engineer of record to convey a record of the completed work. Such updates shall include

building envelope, mechanical, plumbing, electrical and control drawings red-lined, or redrawn if specified,

that show all changes to size, type and locations of components, equipment and assemblies. Record

documents shall include the location and model number of each piece of equipment as installed. The

architect, engineer of record or installing contractor is required to provide consolidated record drawings in

compliance with this section to the building owner or owner’s authorized agent with the timeline specified in

Section C103.6.

C103.6.2 Building operations and maintenance information. Required regular maintenance actions for

equipment and systems shall be clearly stated on a readily visible label on the equipment. The label shall

include the title or publication number for the operation and maintenance manual for that particular model and

type of product and the manufacture date or installation date.

C103.6.2.1 Manuals. An operating and maintenance manual shall be provided for each component, device,

piece of equipment, and system governed by this code. The manual shall include all of the following:

1. Submittal data indicating all selected options for each piece of equipment and control device.

2. Manufacturer's operation manuals and maintenance manuals for each device, piece of equipment,

and system requiring maintenance, except equipment not furnished as part of the project. Required

routine maintenance actions, cleaning and recommended relamping shall be clearly identified.

3. Name and address of at least one service agency.

4. Controls system inspection schedule, maintenance and calibration information, wiring diagrams,

schematics, and control sequence descriptions. A schedule for inspecting and recalibrating all lighting

controls. Desired or field-determined set points shall be PERMANENTLY recorded on control

drawings at control devices or, for digital control systems, on the graphic where settings may be

changed.

5. A narrative of how each system is intended to operate, including recommended set points. Sequence

of operation alone is not acceptable for this requirement.

C103.6.3 Compliance documentation. All energy code compliance forms and calculations shall be delivered

in one document to the building owner as part of the project record documents or manuals, or as a standalone

document. This document shall include the specific energy code year utilized for compliance determination for

each system, NFRC certificates for the installed windows, list of total area for each NFRC certificate, the

interior lighting power compliance path (building area, space-by-space) used to calculate the lighting power

allowance.

For projects complying with Section C401.2 item 1, the documentation shall include:

1. The envelope insulation compliance path (prescriptive or component performance).

2. All completed code compliance forms, and all compliance calculations including, but not limited to, those

required by sections C402.1.5, C403.2.12.1, C405.4, and C405.5.

For projects complying with C401.2 item 2, the documentation shall include:

1. A list of all proposed envelope component types, areas and U-values.

2. A list of all lighting area types with areas, lighting power allowance, and installed lighting power density.

3. A list of each HVAC system modeled with the assigned and proposed system type.

4. Electronic copies of the baseline and proposed model input and output file. The input files shall be in a

format suitable for rerunning the model and shall not consist solely of formatted reports of the inputs

CE-4 2018 Washington State Energy Code

C103.6.4 Systems operation training. Training of the maintenance staff for equipment included in the

manuals required by Section C103.6.2 shall include at a minimum:

1. Review of manuals and permanent certificate.

2. Hands-on demonstration of all normal maintenance procedures, normal operating modes, and all

emergency shutdown and start-up procedures.

3. Training completion report.

SECTION C104

INSPECTIONS

C104.1 General. Construction or work for which a permit is required shall be subject to inspection by the code

official, his or her designated agent, or an approved agency, and such construction or work shall remain visible

and able to be accessed for inspection purposes until approved. Approval as a result of an inspection shall not

be construed to be an approval of a violation of the provisions of this code or of other ordinances of the

jurisdiction. Inspections presuming to give authority to violate or cancel the provisions of this code or of other

ordinances of the jurisdiction shall not be valid. It shall be the duty of the permit applicant to cause the work to

remain visible and able to be accessed for inspection purposes. Neither the code official nor the jurisdiction shall

be liable for expense entailed in the removal or replacement of any material, product, system or building

component required to allow inspection to validate compliance with this code.

C104.2 Required inspections. The code official, his or her designated agent, or an approved agency, upon

notification, shall make the inspections set forth in Sections C104.2.1 through C104.2.6.

C104.2.1 Footing and foundation insulation. Inspections shall verify footing and/or foundation insulation R-

value, location, thickness, depth of burial and protection of insulation as required by the code, approved plans

and specifications.

C104.2.2 Thermal envelope. Inspections shall be made before application of interior finish and shall verify

that envelope components with the correct type of insulation, the R-values, the correct location of insulation,

the correct fenestration, the U-factor, SHGC, VT, and air leakage controls are properly installed as required by

the code, approved plans and specifications, including envelope components in future tenant spaces of multi-

tenant buildings.

C104.2.3 Plumbing system. Inspections shall verify the type of insulation, the R-values, the protection

required, controls, and heat traps as required by the code, approved plans and specifications.

C104.2.4 Mechanical system. Inspections shall verify the installed HVAC equipment for the correct type and

size, controls, duct and piping insulation R-values, duct system and damper air leakage, minimum fan

efficiency, energy recovery and economizer as required by the code, approved plans and specifications.

C104.2.5 Electrical system. Inspections shall verify lighting system controls, components, meters; motors

and installation of an electric meter for each dwelling unit as required by the code, approved plans and

specifications.

C104.2.6 Final inspection. The final inspection shall include verification of the installation and proper

operation of all required building controls, and documentation verifying activities associated with required

building commissioning have been conducted in accordance with Section C408.

C104.3 Reinspection. A building shall be reinspected when determined necessary by the code official.

C104.4 Approved inspection agencies. The code official is authorized to accept reports of approved

inspection agencies, provided such agencies satisfy the requirements as to qualifications and reliability relevant

to the building components and systems they are inspecting.

C104.5 Inspection requests. It shall be the duty of the holder of the permit or their duly authorized agent to

notify the code official when work is ready for inspection. It shall be the duty of the permit holder to provide

access to and means for inspections of such work that are required by this code.

C104.6 Reinspection and testing. Where any work or installation does not pass an initial test or inspection, the

necessary corrections shall be made so as to achieve compliance with this code. The work or installation shall

then be resubmitted to the code official for inspection and testing.

2018 Washington State Energy Code CE-5

C104.7 Approval. After the prescribed tests and inspections indicate that the work complies in all respects with

this code, a notice of approval shall be issued by the code official.

C104.7.1 Revocation. The code official is authorized to, in writing, suspend or revoke a notice of approval

issued under the provisions of this code wherever the certificate is issued in error, or on the basis of incorrect

information supplied, or where it is determined that the building or structure, premise, or portion thereof is in

violation of any ordinance or regulation or any of the provisions of this code.

SECTION C105

VALIDITY

C105.1 General. If a portion of this code is held to be illegal or void, such a decision shall not affect the validity

of the remainder of this code.

SECTION C106

REFERENCED STANDARDS

C106.1 Referenced codes and standards. The codes and standards referenced in this code shall be those

listed in Chapter 5, and such codes and standards shall be considered as part of the requirements of this code

to the prescribed extent of each such reference and as further regulated in Sections C106.1.1 and C106.1.2.

C106.1.1 Conflicts. Where differences occur between provisions of this code and referenced codes and

standards, the provisions of this code shall apply.

C106.1.2 Provisions in referenced codes and standards. Where the extent of the reference to a referenced

code or standard includes subject matter that is within the scope of this code, the provisions of this code, as

applicable, shall take precedence over the provisions in the referenced code or standard.

C106.2 Application of references. References to chapter or section numbers, or to provisions not specifically

identified by number, shall be construed to refer to such chapter, section or provision of this code.

C106.3 Other laws. The provisions of this code shall not be deemed to nullify any provisions of local, state or

federal law. In addition to the requirements of this code, all occupancies shall conform to the provisions included

in the State Building Code (chapter 19.27 RCW). In case of conflicts among the codes enumerated in RCW

19.27.031 (1) through (4) and this code, an earlier named code shall govern over those following. In the case of

conflict between the duct sealing and insulation requirements of this code and the duct insulation requirements

of Sections 603 and 604 of the International Mechanical Code, the duct insulation requirements of this code, or

where applicable, a local jurisdiction's energy code shall govern.

SECTION C107

FEES

C107.1 Fees. A permit shall not be issued until the fees prescribed in Section C107.2 have been paid, nor shall

an amendment to a permit be released until the additional fee, if any, has been paid.

C107.2 Schedule of permit fees. A fee for each permit shall be paid as required, in accordance with the

schedule as established by the applicable governing authority.

C107.3 Work commencing before permit issuance. Any person who commences any work before obtaining

the necessary permits shall be subject to an additional fee established by the code official, which shall be in

addition to the required permit fees.

C107.4 Related fees. The payment of the fee for the construction, alteration, removal or demolition of work

done in connection to or concurrently with the work or activity authorized by a permit shall not relieve the

applicant or holder of the permit from the payment of other fees that are prescribed by law.

C107.5 Refunds. The code official is authorized to establish a refund policy.

CE-6 2018 Washington State Energy Code

SECTION C108

STOP WORK ORDER

C108.1 Authority. Whenever the code official finds any work regulated by this code being performed in a

manner either contrary to the provisions of this code or dangerous or unsafe, the code official is authorized to

issue a stop work order.

C108.2 Issuance. The stop work order shall be in writing and shall be given to the owner of the property

involved, the owner's authorized agent, or to the person doing the work. Upon issuance of a stop work order, the

cited work shall immediately cease. The stop work order shall state the reason for the order, and the conditions

under which the cited work will be permitted to resume.

C108.3 Emergencies. Where an emergency exists, the code official shall not be required to give a written

notice prior to stopping the work.

C108.4 Failure to comply. Any person who shall continue any work after having been served with a stop work

order, except such work as that person is directed to perform to remove a violation or unsafe condition, shall be

liable to a fine as set by the applicable governing authority.

SECTION C109

BOARD OF APPEALS

C109.1 General. In order to hear and decide appeals of orders, decisions or determinations made by the code

official relative to the application and interpretation of this code, there shall be and is hereby created a board of

appeals. The code official shall be an ex officio member of said board but shall have no vote on any matter

before the board. The board of appeals shall be appointed by the governing body and shall hold office at its

pleasure. The board shall adopt rules of procedure for conducting its business, and shall render all decisions

and findings in writing to the appellant with a duplicate copy to the code official.

C109.2 Limitations on authority. An application for appeal shall be based on a claim that the true intent of this

code or the rules legally adopted thereunder have been incorrectly interpreted, the provisions of this code do not

fully apply or an equally good or better form of construction is proposed. The board shall have no authority to

waive requirements of this code.

C109.3 Qualifications. The board of appeals shall consist of members who are qualified by experience and

training and are not employees of the jurisdiction.

SECTION C110

VIOLATIONS

It shall be unlawful for any person, firm, or corporation to erect or construct any building, or remodel or

rehabilitate any existing building or structure in the state, or allow the same to be done, contrary to or in violation

of any of the provisions of this code.

SECTION C111

LIABILITY

Nothing contained in this code is intended to be nor shall be construed to create or form the basis for any liability

on the part of any city or county or its officers, employees or agents for any injury or damage resulting from the

failure of a building to conform to the provisions of this code.

2018 Washington State Energy Code CE-7

CHAPTER 2 [CE]

DEFINITIONS

SECTION C201

GENERAL

C201.1 Scope. Unless stated otherwise, the following words and terms in this code shall have the

meanings indicated in this chapter.

C201.2 Interchangeability. Words used in the present tense include the future; words in the masculine

gender include the feminine and neuter; the singular number includes the plural and the plural includes

the singular.

C201.3 Terms defined in other codes. Terms that are not defined in this code but are defined in the

International Building Code, International Fire Code, International Fuel Gas Code, International

Mechanical Code, Uniform Plumbing Code or the International Residential Code shall have the meanings

ascribed to them in those codes.

C201.4 Terms not defined. Terms not defined by this chapter shall have ordinarily accepted meanings

such as the context implies.

SECTION C202

GENERAL DEFINITIONS

ABOVE-GRADE WALL. A wall enclosing conditioned space that is not a below-grade wall. This includes

between-floor spandrels, peripheral edges of floors, roof and basement knee walls, dormer walls, gable

end walls, walls enclosing a mansard roof and skylight shafts.

ACCESS (TO). That which enables a device, appliance or equipment to be reached by ready access or by a

means that first requires the removal or movement of a panel or similar obstruction.

ADDITION. An extension or increase in the conditioned space floor area, number of stories, or height of a

building or structure.

AIR BARRIER. One or more materials joined together in a continuous manner to restrict or prevent the

passage of air through the building thermal envelope and its assemblies.

AIR CURTAIN. A device, installed at the building entrance, that generates and discharges a laminar air

stream intended to prevent the infiltration of external, unconditioned air into the conditioned spaces, or the

loss of interior, conditioned air to the outside.

ALTERATION. Any construction, retrofit or renovation to an existing structure other than repair or addition.

Also, a change in a building, electrical, gas, mechanical or plumbing system that involves an extension,

addition or change to the arrangement, type or purpose of the original installation.

APPROVED. Acceptable to the code official.

APPROVED AGENCY. An established and recognized agency regularly engaged in conducting tests or

furnishing inspection services, or furnishing product certification research reports, where such agency has

been approved by the code official.

ATTIC AND OTHER ROOFS. All other roofs, including roofs with insulation entirely below (inside of) the roof

structure (i.e., attics, cathedral ceilings, and single-rafter ceilings), roofs with insulation both above and

below the roof structure, and roofs without insulation but excluding roofs with insulation entirely above

deck and metal building roofs.

AUTOMATIC. Self-acting, operating by its own mechanism when actuated by some impersonal influence,

as, for example, a change in current strength, pressure, temperature or mechanical configuration (see

"Manual").

CE-8 2018 Washington State Energy Code

BELOW-GRADE WALL. That portion of a wall in the building envelope that is entirely below the finish grade

and in contact with the ground.

BLOCK. A generic concept used in energy simulation. It can include one or more thermal zones. It

represents a whole building or portion of a building with the same use type served by the same HVAC

system type.

BOILER, MODULATING. A boiler that is capable of more than a single firing rate in response to a varying

temperature or heating load.

BOILER SYSTEM. One or more boilers, their piping and controls that work together to supply steam or hot

water to heat output devices remote from the boiler.

BUBBLE POINT. The refrigerant liquid saturation temperature at a specified pressure.

BUILDING. Any structure used or intended for supporting or sheltering any use or occupancy, including any

mechanical systems, service water heating systems and electric power and lighting systems located on

the building site and supporting the building.

BUILDING COMMISSIONING. A process that verifies and documents that the building systems have been

installed, and function according to the approved construction documents.

BUILDING ENTRANCE. Any doorway, set of doors, revolving door, vestibule, or other form of portal that is

ordinarily used to gain access to the building or to exit from the building by its users and occupants. This

does not include doors solely used to directly enter mechanical, electrical, and other building utility

service equipment rooms, or doors for emergency egress only.

BUILDING SITE. A contiguous area of land that is under the ownership or control of one entity.

BUILDING THERMAL ENVELOPE. The below-grade walls, above-grade walls, floors, ceilings, roofs, and any

other building element assemblies that enclose conditioned space or provides a boundary between

conditioned space, semiheated space and exempt or unconditioned space.

C-FACTOR (THERMAL CONDUCTANCE). The coefficient of heat transmission (surface to surface) through a

building component or assembly, equal to the time rate of heat flow per unit area and the unit temperature

difference between the warm side and cold side surfaces (Btu/h ft

x °F) [W/(m

x K)].

CAPTIVE KEY DEVICE. A lighting control that will not release the key that activates the override when the

lighting is on.

CAVITY INSULATION. Insulating material located between framing members.

CERTIFIED COMMISSIONING PROFESSIONAL. An individual who is certified by an ANSI/ISO/IEC 17024:2012

accredited organization to lead, plan, coordinate, and manage commissioning teams and implement the

commissioning process.

CHANGE OF OCCUPANCY. A change in the use of a building or a portion of a building that results in any of

the following:

1. A change of occupancy classification.

2. A change from one group to another group within an occupancy classification.

3. Any change in use within a group for which there is a change in the application of the requirements

of this code.

CIRCULATING HOT WATER SYSTEM. A specifically designed water distribution system where one or more

pumps are operated in the service hot water piping to circulate heated water from the water-heating

equipment to the fixture supply and back to the water-heating equipment.

CLERESTORY FENESTRATION. See “Fenestration.”

CLIMATE ZONE. A geographical region based on climatic criteria as specified in this code.

CODE OFFICIAL. The officer or other designated authority charged with the administration and enforcement

of this code, or a duly authorized representative.

COEFFICIENT OF PERFORMANCE (COP) - COOLING. The ratio of the rate of heat removal to the rate of energy

input, in consistent units, for a complete refrigerating system or some specific portion of that system under

designated operating conditions.

2018 Washington State Energy Code CE-9

COEFFICIENT OF PERFORMANCE (COP) - HEATING. The ratio of the rate of heat removal to the rate of heat

delivered to the rate of energy input, in consistent units, for a complete heat pump system, including the

compressor and, if applicable, auxiliary heat, under designated operating conditions.

COMMERCIAL BUILDING. For this code, all buildings not included in the definition of "Residential buildings."

COMPUTER ROOM. A room whose primary function is to house equipment for the processing and storage of

electronic data and that has a design total information technology equipment (ITE) equipment less than

or equal to 20 watts per square foot of conditioned area or a design ITE equipment load less than or

equal to 10 kW.

CONDENSING UNIT. A factory-made assembly of refrigeration components designed to compress and

liquefy a specific refrigerant. The unit consists of one or more refrigerant compressors, refrigerant

condensers (air-cooled, evaporatively cooled, or water-cooled), condenser fans and motors (where used)

and factory-supplied accessories.

CONDITIONED FLOOR AREA. The horizontal projection of the floors associated with the conditioned space.

CONDITIONED SPACE. An area, room or space that is enclosed within the building thermal envelope and

that is directly heated or cooled or that is indirectly heated or cooled. Spaces are indirectly heated or

cooled where they communicate through openings with conditioned spaces, where they are separated

from conditioned spaces by uninsulated walls, floors or ceilings, or where they contain uninsulated ducts,

piping or other sources of heating or cooling.

CONTINUOUS INSULATION (CI). Insulating material that is continuous across all structural members without

metal thermal bridges other than fasteners that have a total cross-sectional area not greater than 0.04

percent of the envelope surface through which they penetrate, and service openings. It is installed on the

interior or exterior or is integral to any opaque surface of the building envelope.

CONTROLLED PLANT GROWTH ENVIRONMENT. Group F and U buildings or spaces that are specifically

controlled to facilitate and enhance plant growth and production by manipulating various indoor

environmental conditions. Technologies include indoor agriculture, cannabis growing, hydroponics,

aquaculture and aquaponics. Controlled indoor environment variables include, but are not limited to,

temperature, air quality, humidity and carbon dioxide.

CURTAIN WALL. Fenestration products used to create an external nonload-bearing wall that is designed to

separate the exterior and interior environments.

DATA ACQUISITION SYSTEM. An electronic system managed by the building owner to collect, tabulate and

display metering information.

DATA CENTER. A room or series of rooms that share Data Center Systems whose primary function is to

house equipment for the processing and storage of electronic data, which has a design total information

technology equipment (ITE) equipment power density exceeding 20 watts per square foot of conditioned

area and a total design ITE equipment load greater than 10 kW.

DATA CENTER SYSTEMS. HVAC systems, electrical systems, equipment, or portions thereof used to

condition ITE or electrical systems in a data center.

DAYLIGHT RESPONSIVE CONTROL. A device or system that provides automatic control of electric light levels

based on the amount of daylight in a space.

DAYLIGHT ZONE. The portion of the building interior floor area that is illuminated by natural daylight through

sidelit and toplit fenestration.

DECORATIVE APPLIANCE, VENTED. A vented appliance wherein the primary function lies in the aesthetic

effect of the flames.

DEMAND CONTROL VENTILATION (DCV). A ventilation system capability that provides for the automatic

reduction of outdoor air intake below design rates when the actual occupancy of spaces served by the

system is less than design occupancy.

DEMAND RECIRCULATION WATER SYSTEM. A water distribution system having one or more recirculation

pumps that pump water from a heated water supply pipe back to the heated water source through a cold

water supply pipe.

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DOOR, GARAGE. Doors rated by ASMA 105 with a single panel or sectional panels.

DOOR, NONSWINGING. Roll-up, tilt-up, metal coiling and sliding doors, access hatches, and all other doors

that are not swinging doors or garage doors with less than or equal to 14 percent glazing.

DOOR, SWINGING. Doors that are hinged on one side and revolving doors.

DUCT. A tube or conduit utilized for conveying air. The air passages of self-contained systems are not to

be construed as air ducts.

DUCT SYSTEM. A continuous passageway for the transmission of air that, in addition to ducts, includes duct

fittings, dampers, plenums, fans and accessory air-handling equipment and appliances.

DWELLING UNIT. A single unit providing complete independent living facilities for one or more persons,

including permanent provisions for living, sleeping, eating, cooking and sanitation.

DX-DEDICATED OUTDOOR AIR SYSTEM UNITS (DX-DOAS UNITS). A type of air-cooled, water-cooled or water

source factory assembled product that dehumidifies 100 percent outdoor air to a low dew point and

includes reheat that is capable of controlling the supply dry-bulb temperature of the dehumidified air to the

designated supply air temperature. This conditioned outdoor air is then delivered directly or indirectly to

the conditioned spaces. It may precondition outdoor air by containing an enthalpy wheel, sensible wheel,

desiccant wheel, plate heat exchanger, heat pipes, or other heat or mass transfer apparatus.

DYNAMIC GLAZING. Any fenestration product that has the fully reversible ability to change its performance

properties, including U-factor, SHGC, or VT.

ECONOMIZER, AIR. A duct and damper arrangement and automatic control system that allows a cooling

system to supply outside air to reduce or eliminate the need for mechanical cooling during mild or cold

weather.

ECONOMIZER, WATER. A system where the supply air of a cooling system is cooled indirectly with water that

is itself cooled by heat or mass transfer to the environment without the use of mechanical cooling.

ELECTRICAL LOAD COEFFICIENT (ELC). In a data center, the ratio of the sum of three specific electrical losses

(or losses calculated from efficiencies) to the ITE load itself. Specifically, ELC equals the sum of the

incoming (to ITE) electrical service losses, UPS losses, and ITE distribution losses all divided by the peak

ITE load. The design ELC is calculated at the full load design condition with active redundant equipment

engaged, and the annual ELC is calculated the same way because it is assumed that ITE runs constantly

at full power all year.

ENCLOSED SPACE. A volume surrounded by solid surfaces such as walls, floors, roofs, and openable

devices such as doors and operable windows.

END USE CATEGORY. A load or group of loads that consume energy in a common or similar manner.

ENERGY ANALYSIS. A method for estimating the annual energy use of the proposed design and standard

reference design based on estimates of energy use.

ENERGY COST. The total estimated annual cost for purchased energy for the building functions regulated

by this code, including applicable demand charges.

ENERGY RECOVERY VENTILATION SYSTEM. Systems that employ air-to-air heat exchangers to recover energy

from exhaust air for the purpose of preheating, precooling, humidifying or dehumidifying outdoor

ventilation air prior to supplying the air to a space, either directly or as part of an HVAC system.

ENERGY SIMULATION TOOL. An approved software program or calculation-based methodology that projects

the annual energy use of a building.

ENERGY SOURCE METER. A meter placed at the source of the incoming energy that measures the energy

delivered to the whole building or metered space.

ENTRANCE DOOR. A vertical fenestration product used for occupant ingress, egress and access in

nonresidential buildings including, but not limited to, exterior entrances utilizing latching hardware and

automatic closers and containing over 50 percent glazing specifically designed to withstand heavy duty

usage.

2018 Washington State Energy Code CE-11

EQUIPMENT ROOM. A space that contains either electrical equipment, mechanical equipment, machinery,

water pumps or hydraulic pumps that are a function of the building's services.

EXTERIOR WALL. Walls including both above-grade walls and below-grade walls.

FAN BRAKE HORSEPOWER (BHP). The horsepower delivered to the fan's shaft. Brake horsepower does not

include the mechanical drive losses (belts, gears, etc.).

FAN EFFICIENCY GRADE (FEG). A numerical rating identifying the fan’s aerodynamic ability to convert shaft

power, or impeller power in the case of a direct-driven fan, to air power.

FAN SYSTEM BHP. The sum of the fan brake horsepower of all fans that are required to operate at fan

system design conditions to supply air from the heating or cooling source to the conditioned space(s) and

return it to the source or exhaust it to the outdoors.

FAN SYSTEM DESIGN CONDITIONS. Operating conditions that can be expected to occur during normal system

operation that result in the highest supply fan airflow rate to conditioned spaces served by the system,

other than during air economizer operation.

FAN SYSTEM MOTOR NAMEPLATE HP. The sum of the motor nameplate horsepower of all fans that are

required to operate at design conditions to supply air from the heating or cooling source to the

conditioned space(s) and return it to the source or exhaust it to the outdoors.

FENESTRATION. Products classified as either skylights or vertical fenestration.

SKYLIGHTS. Glass or other transparent or translucent glazing material installed at a slope of less than 60

degrees (91.05 rad) from horizontal, including unit skylights, tubular daylighting devices and glazing

materials in solariums, sunrooms, roofs and sloped walls.

VERTICAL FENESTRATION. Windows that are fixed or operable, doors with no more than 50 percent

glazed area and glazed block composed of glass or other transparent or translucent glazing materials

and installed at a slope of not less than 60 degrees (91.05 rad) from horizontal. Opaque areas such as

spandrel panels are not considered vertical fenestration.

CLERESTORY FENESTRATION. An upper region of vertical fenestration provided for the purpose of

admitting daylight beyond the perimeter of a space. The entire clerestory fenestration assembly is

installed at a height greater than 8 feet above the finished floor.

FENESTRATION AREA. Total area of the fenestration measured using the rough opening, and including the

glazing, sash and frame.

FENESTRATION PRODUCT, FIELD-FABRICATED. A fenestration product whose frame is made at the

construction site of standard dimensional lumber or other materials that were not previously cut, or

otherwise formed with the specific intention of being used to fabricate a fenestration product or exterior

door. Field fabricated does not include site-built fenestration.

FENESTRATION PRODUCT, SITE-BUILT. A fenestration designed to be made up of field-glazed or field-

assembled units using specific factory cut or otherwise factory-formed framing and glazing units.

Examples of site-built fenestration include storefront systems, curtain walls, and atrium roof systems.

F-FACTOR. The perimeter heat loss factor for slab-on-grade floors (Btu/h x ft x °

) [W/(m x K)].

FLOOR AREA, NET. The actual occupied area not including unoccupied accessory areas such as corridors,

stairways, toilet rooms, mechanical rooms and closets.

FURNACE ELECTRICITY RATIO. The ratio of furnace electricity use to total furnace energy computed as ratio

.= (3.412 x E

)/1000 x E

.+ 3.412 x E

) where E

(average annual auxiliary electrical consumption)

and E

(average annual fuel energy consumption) are defined in Appendix N to Subpart B of Part 430 of

Title 10 of the Code of Federal Regulations and E

is expressed in millions of Btus per year.

GENERAL LIGHTING. Lighting that provides a substantially uniform level of illumination throughout an area.

General lighting shall not include lighting that provides a dissimilar level of illumination to serve a specific

application or decorative feature within such area.

GREENHOUSE. A structure or a thermally isolated area of a building that maintains a specialized sunlit

environment that is used exclusively for, and essential to, the cultivation, protection or maintenance of

plants. Greenhouses are those that are erected for a period of 180 days or more.

CE-12 2018 Washington State Energy Code

GROUP R. Buildings or portions of buildings that contain any of the following occupancies as established in

the International Building Code:

1. Group R-1.

2. Group R-2 where located more than three stories in height above grade plane.

HEAT TRAP. An arrangement of piping and fittings, such as elbows, or a commercially available heat trap

that prevents thermosyphoning of hot water during standby periods.

HEAT TRAP, PIPE CONFIGURED. A pipe configured heat trap is either, as applicable:

1. A device specifically designed for the purpose or an arrangement of tubing that forms a loop of

360 degrees, or

2. Piping that from the point of connection to the water heater (inlet or outlet) includes a length of

piping directed downward before connection to the vertical piping of the supply water or hot-water

distribution system.

HEATED SLAB-ON-GRADE FLOOR. Slab-on-grade floor construction in which the heating elements, hydronic

tubing, or hot air distribution system is in contact with, or placed within or under, the slab.

HEATED WATER CIRCULATION SYSTEM. A water distribution system having one or more recirculation pumps

that pump water from a heated water source through a dedicated hot water circulation pipe or piping

system.

HIGH SPEED DOOR. A nonswinging door used primarily to facilitate vehicular access or material

transportation, with a minimum opening rate of 32 inches (813 mm) per second, a minimum closing rate

of 24 inches (610 mm) per second and that includes an automatic-closing device.

HISTORIC BUILDINGS. Buildings that are listed in or eligible for listing in the National Register of Historic

Places, or designated as historic under an appropriate state or local law.

HUMIDISTAT. A regulatory device, actuated by changes in humidity, used for automatic control of relative

humidity.

HVAC TOTAL SYSTEM PERFORMANCE RATIO (HVAC TSPR). The ratio of the sum of a building’s annual heating

and cooling load in thousands of Btus to the sum of annual carbon emissions in pounds from energy

consumption of the building HVAC systems. Carbon emissions shall be calculated by multiplying site

energy consumption by the carbon emission factors from Table C407.1.

IEC DESIGN H MOTOR. An electric motor that meets all of the following:

1. It is an induction motor designed for use with three-phase power.

2. It contains a cage rotor.

3. It is capable of direct-on-line starting.

4. It has 4, 6 or 8 poles.

5. It is rated from 0.4 kW to 1600 kW at a frequency of 60 Hz.

IEC DESIGN N MOTOR. An electric motor that meets all of the following:

1. It is an inductor motor designed for use with three-phase power.

2. It contains a cage rotor.

3. It is capable of direct-on-line starting.

4. It has 2, 4, 6 or 8 poles.

5. It is rated from 0.4 kW to 1600 kW at a frequency of 60 Hz.

INFILTRATION. The uncontrolled inward air leakage into a building caused by the pressure effects of wind

or the effect of differences in the indoor and outdoor air density or both.

INFORMATION TECHNOLOGY EQUIPMENT (ITE). ITE includes computers, data storage, servers, and

network/communication equipment.

INSULATION ENTIRELY ABOVE DECK. A roof with all insulation:

1. Installed above (outside of) the roof structure; and

2. Continuous (i.e., uninterrupted by framing members).

2018 Washington State Energy Code CE-13

INTEGRATED ENERGY EFFICIENCY RATIO (IEER). A single-number figure of merit expressing cooling part-load

EER efficiency for unitary air-conditioning and heat pump equipment on the basis of weighted operation

at various load capacities for the equipment.

INTEGRATED PART LOAD VALUE (IPLV). A single number figure of merit based on part-load EER, COP, or

kW/ton expressing part-load efficiency for air conditioning and heat pump equipment on the basis of

weighted operation at various load capacities for equipment.

INTEGRATED SEASONAL COEFFICIENT OF PERFORMANCE (ISCOP). A seasonal efficiency number that is a

combined value based on the formula listed in AHRI Standard 920 of the two COP values for the heating

season of a DX-DOAS unit water or air source heat pump, expressed in W/W.

INTEGRATED SEASONAL MOISTURE REMOVAL EFFICIENCY (ISMRE). A seasonal efficiency number that is a

combined value based on the formula listed in AHRI Standard 920 of the four dehumidification moisture

removal efficiency (MRE) ratings required for DX-DOAS units, expressed in lb. of moisture/kWh.

ISOLATION DEVICES. Devices that isolate HVAC zones so they can be operated independently of one

another. Isolation devices include separate systems, isolation dampers and controls providing shutoff at

terminal boxes.

LABELED. Equipment, materials or products to which have been affixed a label, seal, symbol or other

identifying mark of a nationally recognized testing laboratory, approved agency or other organization

concerned with product evaluation that maintains periodic inspection of the production of the above-

labeled items and whose labeling indicates either that the equipment, material or product meets identified

standards or has been tested and found suitable for a specified purpose.

LINER SYSTEM (LS). A system that includes the following:

1. A continuous vapor barrier liner membrane that is installed below the purlins and that is

uninterrupted by framing members.

2. An uncompressed, unfaced insulation resting on top of the liner membrane and located between

the purlins.

For multilayer installations, the last rated R-value of insulation is for unfaced insulation draped over

purlins and then compressed when the metal roof panels are attached.

LISTED. Equipment, materials, products or services included in a list published by an organization

acceptable to the code official and concerned with evaluation of products or services that maintains

periodic inspection of production of listed equipment or materials or periodic evaluation of services and

whose listing states either that the equipment, material, product or service meets identified standards or

has been tested and found suitable for a specified purpose.

LOW SLOPED ROOF. A roof having a slope less than 2 units vertical in 12 units horizontal.

LOW-VOLTAGE DRY-TYPE DISTRIBUTION TRANSFORMER. A transformer that is air-cooled, does not use oil as a

coolant, has an input voltage less than or equal to 600 volts and is rated for operation at a frequency of

60 hertz.

LOW-VOLTAGE LIGHTING. A lighting system consisting of an isolating power supply, the low voltage

luminaires, and associated equipment that are all identified for the use.LUMINAIRE. A complete lighting unit

consisting of a lamp or lamps together with the housing designed to distribute the light, position and

protect the lamps, and connect the lamps to the power supply.

LUMINAIRE-LEVEL LIGHTING CONTROL. A lighting system consisting of one or more luminaires where each

luminaire has embedded lighting control logic, occupancy and ambient light sensors, and local override

switching capability, where required. Each luminaire shall also have wireless networking capabilities to

detect and share information with other luminaires to adjust to occupancy and/or daylight in the space.

MANUAL. Capable of being operated by personal intervention (see "Automatic").

MASS TRANSFER DECK SLAB EDGE. That portion of the above-grade wall made up of the concrete slab

where it extends past the footprint of the floor above, and there is space (conditioned or unconditioned)

below the slab. The area of the slab edge shall be defined as the thickness of the slab multiplied by the

perimeter of the edge condition. Examples of this condition include, but are not limited to, the transition

from an above-grade structure to a below-grade structure or the transition from a tower to a podium.

CE-14 2018 Washington State Energy Code

Cantilevered balconies do not meet this definition.

MECHANICAL COOLING. Reducing the temperature of a gas or liquid by using vapor compression,

absorption, desiccant dehumidification combined with evaporative cooling, or another energy-driven

thermodynamic cycle. Indirect or direct evaporative cooling alone is not considered mechanical cooling.

MECHANICAL HEATING. Raising the temperature of a gas or liquid by use of fossil fuel burners, electric

resistance heaters, heat pumps, or other systems that require energy to operate.

MECHANICAL LOAD COEFFICIENT (MLC). In a data center, the ratio of the cooling system’s net use of energy

to that of the ITE. The design MLC is calculated for a local peak weather condition (stipulated in ASHRAE

90.4) and equals the sum of all active cooling equipment input power, divided by total power into the ITE.

The annual MLC is calculated using hourly TMY3 weather data for the data center’s location and equals

the sum of all energy flowing into the cooling system to respond to that weather, minus any energy

successfully recovered to avoid any new energy use, all divided by the energy flowing into the ITE during

the same period.

METAL BUILDING ROOF. A roof that:

1. Is constructed with a metal, structural, weathering surface;

2. Has no ventilated cavity; and

3. Has the insulation entirely below deck (i.e., does not include composite concrete and metal deck

construction nor a roof framing system that is separated from the superstructure by a wood

substrate) and whose structure consists of one or more of the following configurations:

a. Metal roofing in direct contact with the steel framing members;

b. Metal roofing separated from the steel framing members by insulation;

c. Insulated metal roofing panels installed as described in item a. or b.

METER. A device that measures the flow of energy.

MICROCELL. A wireless communication facility consisting of an antenna that is either: (a) Four (4) feet in

height and with an area of not more than 580 square inches; or (b) if a tubular antenna, no more than four

(4) inches in diameter and no more than six (6) feet in length; and the associated equipment cabinet that

is six (6) feet or less in height and no more than 48 square feet in floor area.

NAMEPLATE HORSEPOWER. The nominal motor output power rating stamped on the motor nameplate.

NEMA DESIGN A MOTOR. A squirrel-cage motor that meets all of the following:

1. It is designed to withstand full-voltage starting and developing locked-rotor torque as shown in

paragraph 12.38.1 of NEMA MG 1.

2. It has pull-up torque not less than the values shown in paragraph 12.40.1 of NEMA MG 1.

3. It has breakdown torque not less than the values shown in paragraph 12.39.1 of NEMA MG 1.

4. It has a locked-rotor current higher than the values shown in paragraph 12.35.1 of NEMA MG 1 for

60 Hz and paragraph 12.35.2 of NEMA MG 1 for 50 Hz.

5. It has a slip at rated load of less than 5 percent for motors with fewer than 10 poles.

2018 Washington State Energy Code CE-15

NEMA DESIGN B MOTOR. A squirrel-cage motor that meets all of the following:

1. It is designed to withstand full-voltage starting.

2. It develops locked-rotor, breakdown and pull-up torques adequate for general application as

specified in Sections 12.38, 12.39 and 12.40 of NEMA MG 1.

3. It draws locked-rotor current not to exceed the values shown in paragraph 12.35.1 of NEMA MG 1

for 60 Hz and paragraph 12.35.2 of NEMA MG 1 for 50 Hz.

4. It has a slip at rated load of less than 5 percent for motors with fewer than 10 poles.

NEMA DESIGN C MOTOR. A squirrel-cage motor that meets all of the following:

1. It is designed to withstand full-voltage starting and developing locked-rotor torque for high-torque

applications up to the values shown in paragraph 12.38.2 of NEMA MG 1 (incorporated by

reference; see §431.15).

2. It has pull-up torque not less than the values shown in paragraph 12.40.2 of NEMA MG 1.

3. It has breakdown torque not less than the values shown in paragraph 12.39.2 of NEMA MG 1.

4. It has a locked-rotor current not to exceed the values shown in paragraph 12.35.1 of NEMA MG 1

for 60 Hz and paragraph 12.35.2 of NEMA MG 1 for 50 Hz.

5. It has a slip at rated load of less than 5 percent.

NETWORKED GUEST ROOM CONTROL SYSTEM. A control system, able to be accessed from the front desk or

other central location associated with a Group R-1 building, that is capable of identifying the occupancy

status of each guest room according to a timed schedule, and is capable of controlling HVAC in each

hotel and motel guest room separately.

NONSTANDARD PART LOAD VALUE (NPLV). A single-number part-load efficiency figure of merit calculated and

referenced to conditions other than IPLV conditions, for units that are not designed to operate at ARI

standard rating conditions.

OCCUPANT SENSOR CONTROL. An automatic control device or system that detects the presence or absence

of people within an area and causes lighting, equipment or appliances to be regulated accordingly.

ON-SITE RENEWABLE ENERGY. Energy derived from solar radiation, wind, waves, tides, landfill gas, biogas,

biomass, or the internal heat of the earth. The energy system providing on-site renewable energy shall be

located on the project site.

OPAQUE DOOR. A door that is not less than 50 percent opaque in surface area.

PERSONAL WIRELESS SERVICE FACILITY. A wireless communication facility (WCF), including a microcell,

which is a facility for the transmission and/or reception of radio frequency signals and which may include

antennas, equipment shelter or cabinet, transmission cables, a support structure to achieve the

necessary elevation, and reception and/or transmission devices or antennas.

POWERED ROOF/WALL VENTILATORS. A fan consisting of a centrifugal or axial impeller with an integral driver

in a weather-resistant housing and with a base designed to fit, usually by means of a curb, over a wall or

roof opening.

POWER-OVER-ETHERNET LIGHTING (POE). Lighting sources powered by DC current utilizing Ethernet cables.

PROPOSED DESIGN. A description of the proposed building used to estimate annual energy use and carbon

emissions from energy consumption for determining compliance based on total building performance and

HVAC total performance ratio.

PUBLIC LAVATORY FAUCET. A lavatory faucet that is not intended for private use as defined by the Uniform

Plumbing Code and that is supplied with both potable cold and hot water.

RADIANT HEATING SYSTEM. A heating system that transfers heat to objects and surfaces within a

conditioned space, primarily by infrared radiation.

READY ACCESS (TO). That which enables a device, appliance or equipment to be directly reached, without

requiring the removal or movement of any panel or similar obstruction.

REFRIGERANT DEW POINT. The refrigerant vapor saturation temperature at a specified pressure.

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REFRIGERATED WAREHOUSE COOLER. An enclosed storage space that has a total chilled storage area of

3,000 square feet or greater and is designed to maintain a temperature of greater than 32°F but less than

55°F.

REFRIGERATED WAREHOUSE FREEZER. An enclosed storage space that has a total chilled storage area of

3,000 ft

and is designed to maintain temperatures at or below 32°F.

REFRIGERATION SYSTEM, LOW TEMPERATURE. Systems for maintaining food product in a frozen state in

refrigeration applications.

REFRIGERATION SYSTEM, MEDIUM TEMPERATURE. Systems for maintaining food product above freezing in

refrigeration applications.

REGISTERED DESIGN PROFESSIONAL. An individual who is registered or licensed to practice their respective

design profession as defined by the statutory requirements of the professional registration laws of the

state or jurisdiction in which the project is to be constructed.

REPAIR. The reconstruction or renewal of any part of an existing building.

REPLACEMENT AIR. Outdoor air that is used to replace air removed from a building through an exhaust

system. Replacement air may be derived from one or more of the following: makeup air, supply air,

transfer air and infiltration. However, the ultimate source of all replacement air is outdoor air. When

replacement air exceeds exhaust, the result is exfiltration.

REROOFING. The process of recovering or replacing an existing roof covering. See “Roof Recover” and

“Roof Replacement.”

RESIDENTIAL BUILDING. For this code, includes detached one- and two-family dwellings and multiple single-

family dwellings (townhouses) as well as Group R-2 and R-3 buildings three stories or less in height

above grade plane.

ROOF ASSEMBLY. A system designed to provide weather protection and resistance to design loads. The

system consists of a roof covering and roof deck or a single component serving as both the roof covering

and the roof deck. A roof assembly includes the roof covering, underlayment, roof deck, insulation, vapor

retarder and interior finish. See also attic and other roofs, metal building roof, roof with insulation entirely

above deck and single-rafter roof.

ROOF RECOVER. The process of installing an additional roof covering over a prepared existing roof

covering without removing the existing roof covering.

ROOF REPAIR. Reconstruction or renewal of any part of an existing roof for the purposes of its

maintenance.

ROOF REPLACEMENT. The process of removing the existing roof covering, repairing any damaged substrate

and installing a new roof covering.

ROOFTOP MONITOR. A raised section of a roof containing vertical fenestration along one or more sides.

R-VALUE (THERMAL RESISTANCE). The inverse of the time rate of heat flow through a body from one of its

bounding surfaces to the other surface for a unit temperature difference between the two surfaces, under

steady state conditions, per unit area (h

°F/Btu) [(m

K)/W].

SATURATED CONDENSING TEMPERATURE. The saturation temperature corresponding to the measured

refrigerant pressure at the condenser inlet for single component and azeotropic refrigerants, and the

arithmetic average of the dew point and bubble point temperatures corresponding to the refrigerant

pressure at the condenser entrance for zeotropic refrigerants.

SEMI-HEATED SPACE. An enclosed space within a building, including adjacent connected spaces separated

by an uninsulated component (e.g., basements, utility rooms, garages, corridors), which:

1. Is heated but not cooled, and has an installed heating system output capacity greater than or equal

to 3.4 Btu/(h-ft

) but not greater than 8 Btu/(h-ft

);

2. Is not a walk-in or warehouse cooler or freezer space.

SENSIBLE RECOVERY EFFECTIVENESS. Change in the dry-bulb temperature of the outdoor air supply divided

by the difference between the outdoor air and return air dry-bulb temperatures, expressed as a

percentage, governed by AHRI Standard 1060.

2018 Washington State Energy Code CE-17

SERVICE WATER HEATING. Heating water for domestic or commercial purposes other than space heating

and process requirements.

SIDELIT. See Section C405.2.4.2.

SINGLE-RAFTER ROOF. A roof where the roof above and the ceiling below are both attached to the same

wood rafter and where insulation is located in the space between these wood rafters.

SKYLIGHT. See “Fenestration.”

SLAB BELOW GRADE. Any portion of a slab floor in contact with the ground which is more than 24 inches

below the final elevation of the nearest exterior grade.

SLAB-ON-GRADE FLOOR. That portion of a slab floor of the building envelope that is in contact with the

ground and that is either above grade or is less than or equal to 24 inches below the final elevation of the

nearest exterior grade.

SLEEPING UNIT. A room or space in which people sleep, which can also include permanent provisions for

living, eating, and either sanitation or kitchen facilities but not both. Such rooms and spaces that are also

part of a dwelling unit are not sleeping units.

SMALL BUSINESS. Any business entity (including a sole proprietorship, corporation, partnership or other

legal entity) which is owned and operated independently from all other businesses, which has the

purpose of making a profit, and which has fifty or fewer employees.

SMALL ELECTRIC MOTOR. A general purpose, alternating current, single speed induction motor.

SOLAR HEAT GAIN COEFFICIENT (SHGC). The ratio of the solar heat gain entering the space through the

fenestration assembly to the incident solar radiation. Solar heat gain includes directly transmitted solar

heat and absorbed solar radiation which is then reradiated, conducted or convected into the space.

SPACE CONDITIONING CATEGORY. Categories are based on the allowed peak space conditioning output

capacity per square foot of conditioned floor area, or the design set point temperature, for a building or

space. Space conditioning categories from lowest to highest include: low energy, semi-heated,

conditioned, refrigerated walk-in and warehouse coolers, and refrigerated walk-in and warehouse

freezers.

STANDARD REFERENCE DESIGN. A version of the proposed design that meets the minimum requirements of

this code and is used to determine the maximum annual energy use requirement and carbon emissions

from energy consumption for compliance based on total building performance and HVAC total system

performance ratio.

STEEL-FRAMED WALL. A wall with a cavity (insulated or otherwise) whose exterior surfaces are separated

by steel framing members (i.e., typical steel stud walls and curtain wall systems).

STOREFRONT. A system of doors and windows mulled as a composite fenestration structure that has been

designed to resist heavy use. Storefront systems include, but are not limited to, exterior fenestration

systems that span from the floor level or above to the ceiling of the same story on commercial buildings,

with or without mulled windows and doors.

SUBSYSTEM METER. A meter placed downstream of the energy supply meter that measures the energy

delivered to a load or a group of loads.

TEMPORARY GROWING STRUCTURE. A temporary growing structure has sides and roof covered with

polyethylene, polyvinyl or similar flexible synthetic material and is used to provide plants with either frost

protection or increased heat retention. Temporary structures are those that are erected for a period of

less than 180 days.

THERMOSTAT. An automatic control device used to maintain temperature at a fixed or adjustable set point.

TIME SWITCH CONTROL. An automatic control device or system that controls lighting or other loads,

including switching off, based on time schedules.

TOPLIT. See Section C405.2.4.3

TUBULAR DAYLIGHTING DEVICE (TDD). A non-operable skylight device primarily designed to transmit daylight

from a roof surface to an interior ceiling surface via a tubular conduit. The device consists of an exterior

CE-18 2018 Washington State Energy Code

glazed weathering surface, a light transmitting tube with a reflective inside surface and an interior sealing

device, such as a translucent ceiling panel.

U-FACTOR (THERMAL TRANSMITTANCE). The coefficient of heat transmission (air to air) through a building

component or assembly, equal to the time rate of heat flow per unit area and unit temperature difference

between the warm side and cold side air films (Btu/h

°F) [W/(m

x K)].

UNHEATED SLAB-ON-GRADE FLOOR. A slab-on-grade floor that is not a heated slab-on-grade floor.

UNIFORM ILLUMINATION. A quality of illumination delivered by a lighting system typically comprised of

similar fixtures mounted at a regular spacing interval. This lighting system provides a uniform contrast

ratio of no greater that 5:1 maximum-to-minimum ratio throughout the entire area served, including task

areas.

VARIABLE REFRIGERANT FLOW SYSTEM. An engineered direct-expansion (DX) refrigerant system that

incorporates a common condensing unit, at least one variable capacity compressor, a distributed

refrigerant piping network to multiple indoor fan heating and cooling units each capable of individual zone

temperature control, through integral zone temperature control devices and a common communications

network. Variable refrigerant flow utilizes three or more steps of control on common interconnecting

piping.

VENTILATION. The natural or mechanical process of supplying conditioned or unconditioned air to, or

removing such air from, any space.

VENTILATION AIR. That portion of supply air that comes from outside (outdoors) plus any recirculated air

that has been treated to maintain the desired quality of air within a designated space.

VERTICAL FENESTRATION. See “Fenestration.”

VISIBLE TRANSMITTANCE [VT]. The ratio of visible light entering the space through the fenestration product

assembly to the incident visible light, visible transmittance, includes the effects of glazing material and

frame and is expressed as a number between 0 and 1. For skylights, VT shall be measured and rated in

accordance with NFRC 202.

VISIBLE TRANSMITTANCE – ANNUAL [VT-ANNUAL]. The ratio of visible light entering the space through the

fenestration product assembly to the incident visible light during the course of a year, visible

transmittance, which includes the effects of glazing material, frame, and light well or tubular conduit, and

is expressed as a number between 0 and 1. For tubular daylighting devices, VT-annual shall be

measured and rated in accordance with NFRC 203.

VOLTAGE DROP. A decrease in voltage caused by losses in the wiring system that connect the power

source to the load.

WALK-IN COOLER. An enclosed storage space capable of being refrigerated to temperatures above 32°F

but less than 55°F that can be walked into, has a ceiling height of not less than 7 feet (2134 mm) and has

a total chilled storage area of less than 3,000 ft

WALK-IN FREEZER. An enclosed storage space capable of being refrigerated to temperatures at or below

32°F that can be walked into, has a ceiling height of not less than 7 feet and has a total chilled storage

area of less than 3,000 ft

WALL. That portion of the building envelope, including opaque area and fenestration, that is vertical or

tilted at an angle of 60 degrees from horizontal or greater. This includes above-grade walls and below-

grade walls, between floor spandrels, peripheral edges of floors, and foundation walls.

WALL, METAL BUILDING. A wall whose structure consists of metal spanning members supported by steel

structural members (i.e., does not include spandrel glass or metal panels in curtain wall systems).

WALL, WOOD-FRAMED AND OTHER. All other wall types, including wood stud walls.

WATER HEATER. Any heating appliance or equipment that heats potable water and supplies such water to

the potable hot water distribution system.

ZONE. A space or group of spaces within a building with heating or cooling requirements that are

sufficiently similar so that desired conditions can be maintained throughout using a single controlling

device.

2018 Washington State Energy Code CE-19

CHAPTER 3 [CE]

GENERAL REQUIREMENTS

SECTION C301

CLIMATE ZONES

C301.1 General. Climate zones from Table C301.1 shall be used in determining the applicable requirements

from Chapter 4.

TABLE C301.1

CLIMATE ZONES, MOISTURE REGIMES,

AND WARM-HUMID DESIGNATIONS

BY STATE AND COUNTY

Key: A – Moist, B - Dry, C - Marine

Absence of moisture designation indicates moisture regime is irrelevant

WASHINGTON

5B Adams

4C Grays Harbor

4C Pierce

5B Asotin

4C Island

4C San Juan

5B Benton

4C Jefferson

4C Skagit

5B Chelan

4C King

5B Skamania

4C Clallam

4C Kitsap

4C Snohomish

4C Clark

5B Kittitas

5B Spokane

5B Columbia

5B Klickitat

5B Stevens

4C Cowlitz

4C Lewis

4C Thurston

5B Douglas

5B Lincoln

4C Wahkiakum

5B Ferry

4C Mason

5B Walla Walla

5B Franklin

5B Okanogan

4C Whatcom

5B Garfield

4C Pacific

5B Whitman

5B Grant

5B Pend Oreille

5B Yakima

SECTION C302

DESIGN CONDITIONS

C302.1 Interior design conditions. The interior design temperatures used for heating and cooling load

calculations shall be a maximum of 72°F (22°C) for heating and minimum of 75°F (24°C) for cooling.

C302.2 Exterior design conditions. The heating or cooling outdoor design temperatures shall be selected from

Appendix C.

SECTION C303

MATERIALS, SYSTEMS AND EQUIPMENT

C303.1 Identification. Materials, systems and equipment shall be identified in a manner that will allow a

determination of compliance with the applicable provisions of this code.

C303.1.1 Building thermal envelope insulation. An R-value identification mark shall be applied by the

manufacturer to each piece of building thermal envelope insulation 12 inches (305 mm) or greater in width.

CE-20 2018 Washington State Energy Code

Alternatively, the insulation installers shall provide a certification listing the type, manufacturer and R-value of

insulation installed in each element of the building thermal envelope. For blown or sprayed insulation

(fiberglass and cellulose), the initial installed thickness, settled thickness, settled R-value, installed density,

coverage area and number of bags installed shall be listed on the certification. For sprayed polyurethane foam

(SPF) insulation, the installed thickness of the areas covered and R-value of installed thickness shall be listed

on the certification. For insulated siding, the R-value shall be labeled on the product’s package and shall be

listed on the certification. The insulation installer shall sign, date and post the certification in a conspicuous

location on the job site.

Exception: For roof insulation installed above the deck, the R-value shall be labeled as required by the

material standards specified in Table 1508.2 of the International Building Code.

C303.1.1.1 Blown or sprayed roof/ceiling insulation. The thickness of blown-in or sprayed fiberglass and

cellulose roof/ceiling insulation shall be written in inches (mm) on markers for every 300 square feet (28 m

)

of attic area throughout the attic space. The markers shall be affixed to the trusses or joists and marked with

the minimum initial installed thickness with numbers of not less than 1 inch (25 mm) in height. Each marker

shall face the attic access opening. Spray polyurethane foam thickness and installed R-value shall be listed

on certification provided by the insulation installer.

C303.1.2 Insulation mark installation. Insulating materials shall be installed such that the manufacturer's R-

value mark is readily observable upon inspection.

C303.1.3 Fenestration product rating. U-factors of fenestration shall be determined as follows:

1. For windows, doors and skylights, U-factor ratings shall be determined in accordance with NFRC 100.

2. Where required for garage doors and rolling doors, U-factor ratings shall be determined in accordance

with either NFRC 100 or ANSI/DASMA 105.

U-factors shall be determined by an accredited, independent laboratory, and labeled and certified by the

manufacturer.

Products lacking such a labeled U-factor shall be assigned a default U-factor from Table C303.1.3(1),

C303.1.3(2) or C303.1.3(4). The solar heat gain coefficient (SHGC) and visible transmittance (VT) of glazed

fenestration products (windows, glazed doors and skylights) shall be determined in accordance with NFRC

200 by an accredited, independent laboratory, and labeled and certified by the manufacturer. Products lacking

such a labeled SHGC or VT shall be assigned a default SHGC or VT from Table C303.1.3(3).

Exception: Units without NFRC ratings produced by a small business may be assigned default U-factors

from Table C303.1.3(5) for vertical fenestration.

TABLE C303.1.3(1)

DEFAULT GLAZED WINDOW, GLASS DOOR AND SKYLIGHT U-FACTORS

FRAME TYPE

Window and Glass Door

SKYLIGHT

SINGLE

PANE

DOUBLE

PANE

Metal

1.20

0.80

See Table

C303.1.3(4)

Metal with Thermal Break

1.10

0.65

Nonmetal or Metal Clad

0.95

0.55

Glazed Block

0.60

Metal Thermal Break .= A metal thermal break framed window shall incorporate the following minimum design characteristics:

1) The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft

/°F;

2) The thermal break material must produce a gap in the frame material of not less than 0.210 inches; and

3) All metal framing members of the products exposed to interior and exterior air shall incorporate a thermal break meeting the

criteria in 1) and 2) above.

C303.1.4 Insulation product rating. The thermal resistance (R-value) of insulation shall be determined in

accordance with the U.S. Federal Trade Commission R-value rule (C.F.R. Title 16, Part 460) in units of

h × ft

× °F/Btu at a mean temperature of 75°F (24°C).

2018 Washington State Energy Code CE-21

C303.1.4.1 Insulated siding. The thermal resistance (R-value) shall be determined in accordance with

ASTM C1363. Installation for testing shall be in accordance with the manufacturer’s installation instructions.

C303.1.5 Spandrel panels in glass curtain walls. Table C303.1.5 provides default U-factors for the spandrel

section of glass and other curtain wall systems. Design factors that affect performance are the type of framing,

the type of spandrel panel and the R-value of insulation. Four framing conditions are considered in the table.

The first is the common case where standard aluminum mullions are used. Standard mullions provide a

thermal bridge through the insulation, reducing its effectiveness. The second case is for metal framing

members that have a thermal break. A thermal break frame uses a urethane or other non-metallic element to

separate the metal exposed to outside conditions from the metal that is exposed to interior conditions. The

third case is for structural glazing or systems where there are no exposed mullions on the exterior. The fourth

case is for the condition where there is no framing or the insulation is continuous and uninterrupted by

framing. The columns in the table can be used for any specified level of insulation between framing members

installed in framed curtain walls or spandrel panels.

C303.1.5.1 Window wall application. Where “window wall” or similar assembly that is discontinuous at

intermediate slab edges is used, the slab edge U-value shall be as listed in Appendix Table A103.3.7.1(3) or

as determined using an approved calculation.

303.1.5.2 Table value assumptions. In addition to the spandrel panel assembly, the construction assembly

U-factors assume an air gap between the spandrel panel (with an R-value of 1.39) and one layer of 5/8-inch

gypsum board (with an R-value of 0.56) that provides the interior finish. The gypsum board is assumed to

span between the window sill and a channel at the floor. For assemblies that differ from these assumptions,

custom U-factors can be calculated to account for any amount of continuous insulation or for unusual

construction assemblies using Equations 3-1, 3-2 or 3-3 where appropriate. Spandrel panel U-factors for

assemblies other than those covered by this table or Equations 1-3 may be determined using an alternate

approved methodology. Equations 3-1 through 3-3 do not calculate the value of any insulation inboard of the

curtain wall assembly.

Aluminum without Thermal Break (Equation 3-1)

Aluminum with Thermal Break (Equation 3-2)

CE-22 2018 Washington State Energy Code

Structural Glazing (Equation 3-3)

Table C303.1.5

U-Factors for Spandrel Panels and Glass Curtain Walls

Rated R-Value of Insulation Between Framing Members

None

R-4

R-7

R-10

R-15

R-20

R-25

R-30

Frame Type

Spandrel Panel

Aluminum

without

Thermal

Break

Single glass pane,

stone or metal panel

0.360

0.242

0.222

0.212

0.203

0.198

0.195

0.193

Double glass with no

low-e coatings

0.297

0.233

0.218

0.209

0.202

0.197

0.194

0.192

Triple or low-e glass

0.267

0.226

0.214

0.207

0.200

0.196

0.194

0.192

Aluminum

with Thermal

Break

Single glass pane,

stone or metal panel

0.350

0.211

0.186

0.173

0.162

0.155

0.151

0.149

Double glass with no

low-e coatings

0.278

0.200

0.180

0.170

0.160

0.154

0.151

0.148

Triple or low-e glass

0.241

0.191

0.176

0.167

0.159

0.153

0.150

0.148

Structural

Glazing

Single glass pane,

stone or metal panel

0.354

0.195

0.163

0.147

0.132

0.123

0.118

0.114

Double glass with no

low-e coatings

0.274

0.180

0.156

0.142

0.129

0.122

0.117

0.114

Triple or low-e glass

0.231

0.169

0.150

0.138

0.127

0.121

0.116

0.113

No Framing,

or Insulation

is Continuous

Single glass pane,

stone or metal panel

0.360

0.148

0.102

0.078

0.056

0.044

0.036

0.031

Double glass with no

low-e coatings

0.297

0.136

0.097

0.075

0.054

0.043

0.035

0.030

Triple or low-e glass

0.267

0.129

0.093

0.073

0.053

0.042

0.035

0.030

C303.2 Installation. Materials, systems and equipment shall be installed in accordance with the manufacturer's

instructions and the International Building Code or International Residential Code, as applicable.

C303.2.1 Protection of exposed foundation insulation. Insulation applied to the exterior of basement walls,

crawlspace walls and the perimeter of slab-on-grade floors shall have a rigid, opaque and weather-resistant

protective covering to prevent the degradation of the insulation's thermal performance. The protective covering

shall cover the exposed exterior insulation and extend not less than 6 inches (153 mm) below grade.

C303.2.2 Multiple layers of continuous insulation. Where two or more layers of continuous insulation board

are used in a construction assembly, the continuous insulation boards shall be installed in accordance with

Section C303.2. Where the continuous insulation board manufacturer’s instructions do not address installation

of two or more layers, the edge joints between each layer of continuous insulation boards shall be staggered.

2018 Washington State Energy Code CE-23

TABLE C303.1.3(2)

DEFAULT OPAQUE DOOR U-FACTORS

See Appendix A, Section A107

TABLE C303.1.3(3)

DEFAULT GLAZED FENESTRATION

SHGC AND VT

SINGLE GLAZED

DOUBLE

GLAZED

BLOCK

Clear

Tinted

Clear

Tinted

SHGC

0.40

0.6

0.3

0.6

0.3

0.6

TABLE C303.1.3(4)

DEFAULT U-FACTORS FOR SKYLIGHTS

Frame Type

Fenestration Type

Aluminum

Without

Thermal

Break

Aluminum

With

Thermal

Break

Reinforced

Vinyl/

Aluminum-Clad

Wood or Vinyl

Wood or Vinyl-

Clad Wood/

Vinyl without

Reinforcing

Single Glazing

glass

U-1.58

U-1.51

U-1.40

U-1.18

acrylic/polycarb

U-1.52

U-1.45

U-1.34

U-1.11

Double Glazing

air

U-1.05

U-0.89

U-0.84

U-0.67

argon

U-1.02

U-0.86

U-0.80

U-0.64

Double Glazing, e=0.20

air

U-0.96

U-0.80

U-0.75

U-0.59

argon

U-0.91

U-0.75

U-0.70

U-0.54

Double Glazing, e=0.10

air

U-0.94

U-0.79

U-0.74

U-0.58

argon

U-0.89

U-0.73

U-0.68

U-0.52

Double Glazing, e=0.05

air

U-0.93

U-0.78

U-0.73

U-0.56

argon

U-0.87

U-0.71

U-0.66

U-0.50

Triple Glazing

air

U-0.90

U-0.70

U-0.67

U-0.51

argon

U-0.87

U-0.69

U-0.64

U-0.48

Triple Glazing, e=0.20

air

U-0.86

U-0.68

U-0.63

U-0.47

argon

U-0.82

U-0.63

U-0.59

U-0.43

Triple Glazing, e=0.20 on 2 surfaces

air

U-0.82

U-0.64

U-0.60

U-0.44

argon

U-0.79

U-0.60

U-0.56

U-0.40

Triple Glazing, e=0.10 on 2 surfaces

air

U-0.81

U-0.62

U-0.58

U-0.42

argon

U-0.77

U-0.58

U-0.54

U-0.38

Quadruple Glazing, e=0.10 on 2 surfaces

air

U-0.78

U-0.59

U-0.55

U-0.39

argon

U-0.74

U-0.56

U-0.52

U-0.36

krypton

U-0.70

U-0.52

U-0.48

U-0.32

Notes for Table C303.1.3(4)

1. U-factors are applicable to both glass and plastic, flat and domed units, all spacers and gaps.

2. Emissivities shall be less than or equal to the value specified.

3. Gap fill shall be assumed to be air unless there is a minimum of 90% argon or krypton.

4. Aluminum frame with thermal break is as defined in footnote 1 to Table C303.1.3(1).

CE-24 2018 Washington State Energy Code

TABLE C303.1.3(5)

SMALL BUSINESS COMPLIANCE TABLE

DEFAULT U-FACTORS FOR VERTICAL FENESTRATION

Vertical Fenestration Description

Frame Type

Any Frame

Aluminum

Thermal

Break

Wood/Vinyl/

Fiberglass

Panes

Low-e

Spacer

Fill

Double

Any

Argon

0.48

0.41

0.32

Any

Argon

0.46

0.39

0.30

Any

Argon

0.44

0.37

0.28

High

Performance

Argon

0.42

0.35

Deemed to

comply

Triple

Any

Air

0.50

0.44

0.26

Any

Air

0.45

0.39

0.22

Any

Air

0.41

0.34

0.20

Any double

low-e

Any

Air

0.35

0.32

0.18

Low-eA (emissivity) shall be 0.24 to 0.16.

Low-eB (emissivity) shall be 0.15 to 0.08.

Low-eC (emissivity) shall be 0.07 or less.

Aluminum Thermal Break = An aluminum thermal break framed window shall incorporate the following

minimum design characteristics:

a) The thermal conductivity of the thermal break material shall be not more than 3.6 Btu-in/h/ft

/°F;

b) The thermal break material must produce a gap in the frame material of not less than 0.210 inches;

and

c) All metal framing members of the products exposed to interior and exterior air shall incorporate a

thermal break meeting the criteria in a) and b) above.

A minimum air space of 0.375 inches between panes of glass is required for double glazing.

A minimum air space of 0.25 inches between panes of glass is required for triple glazing.

Deemed to comply glazing shall not be used for performance compliance.

2018 Washington State Energy Code CE-25

CHAPTER 4 [CE]

COMMERCIAL ENERGY EFFICIENCY

SECTION C401

GENERAL

C401.1 Scope. The provisions in this chapter are applicable to commercial buildings and their building sites.

C401.2 Application. Commercial buildings shall comply with one of the following:

1. The requirements of Sections C402, C403, C404, C405, C406, C408, C409, C410 and C411.

2. The requirements of Section C407.

3. When adopted by the local jurisdiction, the requirements of Appendix F, Outcome-Based Energy Budget,

Sections C408, C409, C410, C411 and any specific section in Table C407.2 as determined by the local

jurisdiction. The Proposed Total UA of the proposed building shall be no more than 20 percent higher than

the Allowed Total UA as defined in Section C402.1.5.

C401.2.1 Application to existing buildings. Work on existing buildings shall comply with Chapter 5 in

addition to the applicable provisions of Chapter 4.

SECTION C402

BUILDING ENVELOPE REQUIREMENTS

C402.1 General. Building thermal envelope assemblies for buildings that are intended to comply with the code

on a prescriptive basis, in accordance with the compliance path described in Item 1 of Section C401.2, shall

comply with the following:

1. The opaque portions of the building thermal envelope shall comply with the specific insulation requirements

of Section C402.2 and the thermal requirements of either the R-value based method of Section C402.1.3,

the U-, C- and F-factor based method of Section C402.1.4, or the component performance alternative of

Section C402.1.5.

2. Fenestration in the building envelope assemblies shall comply with Section C402.4, or the component

performance alternative of Section C402.1.5.

3. Air leakage of building envelope assemblies shall comply with Section C402.5.

C402.1.1 Low energy buildings, semi-heated buildings and greenhouses. Low energy buildings shall

comply with Section C402.1.1.1. Semi-heated buildings and spaces shall comply with Section C402.1.1.2,

Greenhouses shall comply with Section C402.1.1.3.

C402.1.1.1 Low energy buildings. The following buildings, or portions thereof, separated from the

remainder of the building by building thermal envelope assemblies complying with this code shall be exempt

from all thermal envelope provisions of this code:

1. Those that are heated and/or cooled with a peak design rate of energy usage less than 3.4 Btu/h × ft

(10.7 W/m

) or 1.0 watt/ft

(10.7 W/m

) of floor area for space conditioning purposes.

2. Those that do not contain conditioned space.

3. Unstaffed equipment shelters or cabinets used solely for personal wireless service facilities.

C402.1.1.2 Semi-heated buildings and spaces. The building envelope of semi-heated buildings, or

portions thereof, shall comply with the same requirements as that for conditioned spaces in Section C402,

except as modified by this section. The total installed output capacity of mechanical space conditioning

systems serving a semi-heated building or space shall comply with Section C202. Building envelope

assemblies separating conditioned space from semi-heated space shall comply with the exterior envelope

insulation requirements. Semi-heated spaces heated by mechanical systems that do not include electric

resistance heating equipment are not required to comply with the opaque wall insulation provisions of

Section C402.2.3 for walls that separate semi-heated spaces from the exterior or low energy spaces. Semi-

heated spaces shall be calculated separately from other conditioned spaces for compliance purposes.

CE-26 2018 Washington State Energy Code

Opaque walls in semi-heated spaces shall be calculated as fully code compliant opaque walls for both the

target and proposed for the Target UA calculations for the component performance alternative in Section

C402.1.5, and for the Standard Reference Design for Total Building Performance compliance per Section

C407. The capacity of heat trace temperature maintenance systems complying with Section C404.7.2 that

are provided for freeze protection of piping and equipment only, shall not be included in the total installed

output capacity of mechanical space conditioning systems.

Exception: Building or space may comply as semi-heated when served by one or more of the following

system alternatives:

1. Electric infrared heating equipment for localized heating applications.

2. Heat pumps with cooling capacity permanently disabled, as pre-approved by the jurisdiction.

C402.1.1.3 Greenhouses. Greenhouse structures or areas that comply with all of the following shall be

exempt from the building envelope requirements of this code:

1. Exterior opaque envelope assemblies complying with Sections C402.2 and C402.4.4.

Exception: Low energy greenhouses that comply with Section C402.1.1.1.

2. Interior partition building thermal envelope assemblies that separate the greenhouse from

conditioned space complying with Sections C402.2, C402.4.3 and C402.4.4.

3. Non-opaque envelope assemblies complying with the thermal envelope requirements in Table

C402.1.1.3. The U-factor for the non-opaque roof shall be for the roof assembly or a roof that

includes the assembly and an internal curtain system.

Exception: Unheated greenhouses.

4. No mechanical cooling is provided.

5. For heated greenhouses, heating is provided by a radiant heating system, a condensing natural

gas-fired or condensing propane-fired heating system, or a heat pump with cooling capacity

permanently disabled as pre-approved by the jurisdiction.

TABLE C402.1.1.3

NON-OPAQUE THERMAL ENVELOPE MAXIMUM REQUIREMENTS

Component U-Factor

BTU/h-ft

-°F

Climate Zone 5 and

Marine 4

Non-opaque roof

0.5

Non-opaque SEW wall

0.7

Non-opaque N wall

0.6

C402.1.2 Equipment buildings. Buildings that comply with all of the following shall be exempt from the

building thermal envelope provisions of this code:

1. Are separate buildings with floor area no more than 500 square feet (50 m

2. Are intended to house electronic equipment with installed equipment power totaling at least 7 watts per

square foot (75 W/m

) and not intended for human occupancy.

3. Are served by mechanical cooling and heating systems sized in accordance with Sections C403.1.2 and

C403.3.1.

4. Have a heating system capacity not greater than 17,000 Btu/hr (5 kW) and a heating thermostat set

point that is restricted to not more than 50°F (10°C).

5. Have an average wall and roof U-factor less than 0.200.

Exception: Where the cooling and heating system is a heat pump, the heating system capacity is allowed

to exceed 17,000 Btu/h provided the heat pump cooling efficiency is at least 15 percent better than the

requirements in Table C403.3.2(2).

C402.1.2.1 Standalone elevator hoistways. Elevator hoistways that comply with all of the following shall

be exempt from the building thermal envelope and envelope air barrier provisions of this code:

1. Are separate from any other conditioned spaces in the building (do not serve or open into any

conditioned, semi-heated or indirectly conditioned space).

2. Have heating and/or cooling equipment sized only to serve the expected elevator loads with

thermostat set points restricted to heating to no higher than 40° F and cooling to no lower than 95° F.

3. Have an area-weighted average wall, roof, and floor (where applicable) U-factor of less than or equal

2018 Washington State Energy Code CE-27

to 0.20. Calculations must include any floor-slab-edges that penetrate the hoistway and thus are

considered part of the above-grade walls.

C402.1.3 Insulation component R-value method. Building thermal envelope opaque assemblies shall

comply with the requirements of Section C402.2 based on the climate zone specified in Chapter 3. For

opaque portions of the building thermal envelope intended to comply on an insulation component R-value

basis, the R-values for insulation shall not be less than that specified in Table C402.1.3. Commercial buildings

or portions of commercial buildings enclosing Group R occupancies shall use the R-values from the "Group R"

column of Table C402.1.3. Commercial buildings or portions of commercial buildings enclosing occupancies

other than Group R shall use the R-values from the "All other" column of Table C402.1.3.

TABLE C402.1.3

OPAQUE THERMAL ENVELOPE INSULATION COMPONENT

MINIMUM REQUIREMENTS, R-VALUE METHOD

a, i

CLIMATE ZONE

5 AND MARINE 4

All Other

Group R

Roofs

Insulation entirely above

deck

R-38ci

Metal buildings

R-25 .+

R-11 LS

R-25 .+

R-11 LS

Attic and other

R-49

Walls, Above Grade

Mass

R-9.5

R-13.3ci

Mass transfer deck slab

edge

R-5

Metal building

R-19ci or

R-13+13ci

R-19ci or

R-13+13ci

Steel framed

R-13 .+

R-10ci

R-19 .+

R-8.5ci

Wood framed and other

R-21 int or

R-15+5ci std

R-13+7.5ci std or

R-20+3.8ci std or

R-25 std

Walls, Below Grade

Below-grade wall

d, h

Same as above grade

Floors

Mass

R-30ci

Joist/framing

R-30

Slab-on-Grade Floors

Unheated slabs

R-10 for 24" below

Heated slabs

R-10 perimeter &

under entire slab

R-10 perimeter & under

entire slab

Opaque Doors

Nonswinging

R-4.75

For SI: 1 inch .= 25.4 mm. ci .= Continuous insulation. NR .= No requirement. LS .= Liner system

CE-28 2018 Washington State Energy Code

a. Assembly descriptions can be found in Chapter 2 and Appendix A.

b. Where using R-value compliance method, a thermal spacer block with minimum thickness of ½ inch and minimum

R-value of R-3.5 shall be provided, otherwise use the U-factor compliance method in Table C402.1.4.

c. Exception: Integral insulated concrete block walls complying with ASTM C90 with all cores filled and meeting both

of the following:

1. At least 50 percent of cores must be filled with vermiculite or equivalent fill insulation; and

2. The building thermal envelope encloses one or more of the following uses: Warehouse (storage and retail),

gymnasium, auditorium, church chapel, arena, kennel, manufacturing plant, indoor swimming pool, pump

station, water and waste water treatment facility, storage facility, storage area, motor vehicle service facility.

Where additional uses not listed (such as office, retail, etc.) are contained within the building, the exterior walls

that enclose these areas may not utilize this exception and must comply with the appropriate mass wall R-

value from Table C402.1.3/U-factor from Table C402.1.4.

d. Where heated slabs are below grade, they shall comply with the insulation requirements for heated slabs.

e. Steel floor joist systems shall be insulated to R-38 + R-10ci.

f. “Mass floors” shall include floors weighing not less than:

1.35 pounds per square foot of floor surface area; or

2.25 pounds per square foot of floor surface area where the material weight is not more than 120 pounds per cubic

foot.

g. Not applicable to garage doors. See Table C402.1.4.

h. Peripheral edges of intermediate concrete floors are included in the above grade mass wall category and therefore

must be insulated as above grade mass walls unless they meet the definition of Mass Transfer Deck Slab Edge.

The area of the peripheral edges of concrete floors shall be defined as the thickness of the slab multiplied by the

perimeter length of the edge condition. See Table A103.3.7.2 for typical default u-factors for above grade slab

edges and footnote c for typical conditions of above grade slab edges.

i. For roof, wall or floor assemblies where the proposed assembly would not be continuous insulation, an alternate

nominal R-value compliance option for assemblies with isolated metal penetrations of otherwise continuous

insulation is:

Assemblies with

continuous

insulation (see

definition)

Alternate option for assemblies with

metal penetrations, greater than

0.04% but less than 0.08%

Alternate option for assemblies with

metal penetrations, greater than or

equal to 0.08% but less than 0.12%

R-9.5ci

R-11.9ci

R-13ci

R-11.4ci

R-14.3ci

R-15.7ci

R-13.3ci

R-16.6ci

R-18.3ci

R-15.2ci

R-19.0ci

R-21ci

R-30ci

R-38ci

R-42ci

R-38ci

R-48ci

R-53ci

R-13 + R-7.5ci

R-13 + R-9.4ci

R-13 + R-10.3ci

R-13 + R-10ci

R-13 + R-12.5ci

R-13 + R-13.8ci

R-13 + R-12.5ci

R-13 + R-15.6ci

R-13 + R-17.2ci

R-13 + R-13ci

R-13 + R-16.3ci

R-13 + R-17.9ci

R-19 + R-8.5ci

R-19 + R-10.6ci

R-19 + R-11.7ci

R-19 + R-14ci

R-19 + R-17.5ci

R-19 + R-19.2ci

R-19 + R-16ci

R-19 + R-20ci

R-19 + R-22ci

R-20 + R-3.8ci

R-20 + R-4.8ci

R-20 .+ R-5.3ci

R-21 + R-5ci

R-21 + R-6.3ci

R-21 + R-6.9ci

This alternate nominal R-value compliance option is allowed for projects complying with all of the following:

1. The ratio of the cross-sectional area, as measured in the plane of the surface, of metal penetrations of

otherwise continuous insulation to the opaque surface area of the assembly is greater than 0.0004 (0.04%),

but less than 0.0012 (0.12%).

2. The metal penetrations of otherwise continuous insulation are isolated or discontinuous (e.g., brick ties or

other discontinuous metal attachments, offset brackets supporting shelf angles that allow insulation to go

between the shelf angle and the primary portions of the wall structure). No continuous metal elements (e.g.,

metal studs, z-girts, z-channels, shelf angles) penetrate the otherwise continuous portion of the insulation.

3. Building permit drawings shall contain details showing the locations and dimensions of all the metal

2018 Washington State Energy Code CE-29

penetrations (e.g., brick ties or other discontinuous metal attachments, offset brackets, etc.) of otherwise

continuous insulation. In addition, calculations shall be provided showing the ratio of the cross-sectional area

of metal penetrations of otherwise continuous insulation to the overall opaque wall area.

For other cases where the proposed assembly is not continuous insulation, see Section C402.1.4 for

determination of U-factors for assemblies that include metal other than screws and nails.

C402.1.4 Assembly U-factor, C-factor or F-factor based method. Building thermal envelope opaque

assemblies shall meet the requirements of Section C402.2 based on the climate zone specified in Chapter 3.

Building thermal envelope opaque assemblies intended to comply on an assembly U-, C-, or F-factor basis

shall have a U-, C-, or F-factor not greater than that specified in Table C402.1.4. Commercial buildings or

portions of commercial buildings enclosing Group R occupancies shall use the U-, C-, or F-factor from the

“Group R” column of Table C402.1.4. Commercial buildings or portions of commercial buildings enclosing

occupancies other than Group R shall use the U-, C-, or F-factor from the “All Other” column of Table

C402.1.4. The U-factors for typical construction assemblies are included in Appendix A. These values shall be

used for all calculations. Where proposed construction assemblies are not represented in Appendix A, values

shall be calculated in accordance with the ASHRAE Handbook of Fundamentals using the framing factors

listed in Appendix A where applicable and shall include the thermal bridging effects of framing materials.

C402.1.4.1 Thermal resistance of cold-formed steel stud walls. U-factors of walls with cold-formed steel

studs shall be permitted to be determined in accordance with Equation 4-1:

U = 1/[Rs + (ER)] (Equation 4-1)

where:

Rs = The cumulative R-value of the wall components along the path of heat transfer, excluding the cavity

insulation and steel studs.

ER = The effective R-value of the cavity insulation with steel studs.

CE-30 2018 Washington State Energy Code

TABLE C402.1.4

OPAQUE THERMAL ENVELOPE ASSEMBLY MAXIMUM REQUIREMENTS, U-FACTOR METHOD

a, f

CLIMATE ZONE 5 AND MARINE 4

All Other

Group R

Roofs

Insulation entirely above deck

U-0.027

Metal buildings

U-0.031

Attic and other

U-0.021

Joist or single rafter

U-0.027

Walls, Above Grade

Mass

U-0.104

U-0.078

Mass transfer deck slab edge

U-0.20

Metal building

U-0.052

Steel framed

U-0.055

Wood framed and other

U-0.054

U-0.051

Walls, Below Grade

Below-grade wall

b,g

Same as above

grade

Same as above

grade

Floors

Mass

U-0.031

Joist/framing

U-0.029

Slab-on-Grade Floors

Unheated slabs

F-0.54

Heated slabs

F-0.55

Opaque Doors

Swinging door

U-0.37

Nonswinging door

U-0.34

Garage door <14% glazing

U-0.31

a. Use of opaque assembly U-factors, C-factors, and F-factors from Appendix A is required unless otherwise allowed

by Section C402.1.4.

b. Where heated slabs are below grade, they shall comply with the F-factor requirements for heated slabs.

c. Heated slab F-factors shall be determined specifically for heated slabs. Unheated slab factors shall not be used.

d. Exception: Integral insulated concrete block walls complying with ASTM C90 with all cores filled and meeting both

of the following:

1. At least 50 percent of cores must be filled with vermiculite or equivalent fill insulation; and

2. The building thermal envelope encloses one or more of the following uses: Warehouse (storage and retail),

gymnasium, auditorium, church chapel, arena, kennel, manufacturing plant, indoor swimming pool, pump

station, water and waste water treatment facility, storage facility, storage area, motor vehicle service facility.

Where additional uses not listed (such as office, retail, etc.) are contained within the building, the exterior

2018 Washington State Energy Code CE-31

walls that enclose these areas may not utilize this exception and must comply with the appropriate mass wall

R-value from Table C402.1.3/U-factor from Table C402.1.4.

e. “Mass floors” shall include floors weighing not less than:

1.35 pounds per square foot of floor surface area; or

2.25 pounds per square foot of floor surface area where the material weight is not more than 120 pounds per cubic

foot.

f. Opaque assembly U-factors based on designs tested in accordance with ASTM C1363 shall be permitted. The R-

value of continuous insulation shall be permitted to be added or subtracted from the original test design.

g. Peripheral edges of intermediate concrete floors are included in the above grade mass wall category and therefore

must be insulated as above grade mass walls unless they meet the definition of Mass Transfer Deck Slab Edge. The

area of the peripheral edges of concrete floors shall be defined as the thickness of the slab multiplied by the perimeter

length of the edge condition. See Table A103.3.7.2 for typical default u-factors for above grade slab edges and

footnote c for typical conditions of above grade slab edges.

TABLE C402.1.4.1

EFFECTIVE R-VALUES FOR STEEL STUD WALL ASSEMBLIES

NOMINAL

STUD DEPTH

(inches)

SPACING OF

FRAMING

(inches)

CAVITY

R-VALUE

(insulation)

CORRECTION

FACTOR (Fc)

EFFECTIVE

R-VALUE (ER)

(Cavity

R-Value x Fc)

3 1/2

0.46

5.98

0.43

6.45

3 1/2

0.55

7.15

0.52

7.80

0.37

7.03

0.35

7.35

0.45

8.55

0.43

9.03

0.31

7.75

0.38

9.50

C402.1.5 Component performance alternative. Building envelope values and fenestration areas determined

in accordance with Equation 4-2 shall be permitted in lieu of compliance with the U-factors and F-factors in

Table C402.1.4 and C402.4 and the maximum allowable fenestration areas in Section C402.4.1.

For buildings with more than one space conditioning category, component performance compliance shall be

demonstrated separately for each space conditioning category. Interior partition ceilings, walls, fenestration

and floors that separate space conditioning areas shall be applied to the component performance calculations

for the space conditioning category with the highest level of space conditioning.

CE-32 2018 Washington State Energy Code

Proposed Total UA ≤ Allowable Total UA (Equation 4-2)

Where:

Proposed Total UA

UA-glaz-prop + UA sky-prop + UA-opaque-prop + FL-slab-prop

Allowable Total UA

UA-glaz-allow + UA-glaz-excess + UA sky-allow + UA-sky-excess + UA-opaque-allow +

FL-slab-allow

UA-glaz-prop

Sum of (proposed U-value

proposed area) for each distinct vertical fenestration type,

up to code maximum area

UA-sky-prop

Sum of (proposed U-value

proposed area) for each distinct skylight type, up to the code

maximum area

UA-opaque-prop

Sum of (proposed U-value

proposed area) for each distinct opaque thermal envelope type

FL-slab-prop

Sum of (proposed F-value

proposed length) for each distinct slab on grade perimeter

assembly

UA-glaz-allow

Sum of (code maximum vertical fenestration U-value from Table C402.4, or Section

C402.4.1.1.2 if applicable,

proposed area) for each distinct vertical fenestration type, not

to exceed the code maximum area

UA-glaz-excess

U-value for the proposed wall type from Table C402.4

vertical fenestration area in excess

of the code maximum area

UA-sky-allow

Sum of (code maximum skylight U-value from Table C402.4

proposed area) for each

distinct skylight type proposed, not to exceed the code maximum area

UA-sky-excess

U-value for the proposed roof type from Table C402.4

skylight area in excess of the code

maximum area

UA-opaque-allow

Code maximum opaque envelope U-value from Table C402.1.4 for each opaque door, wall,

roof, and floor assembly

proposed area

FL-slab-allow

Code maximum F-value for each slab-on-grade perimeter assembly

proposed length

Notes

1. Where multiple vertical fenestration types are proposed and the code maximum area is exceeded, the U-value shall

be the average Table C402.1.4 U-value weighted by the proposed vertical fenestration area of each type.

2. Where multiple wall types are proposed the U-value shall be the average Table C402.1.4 U-value weighted by the

proposed above grade wall area of each type.

3. Where multiple roof types are proposed the U-value shall be the average Table C402.1.4 U-value weighted by the

proposed roof area of each type.

C402.1.5.1 Component U-factors. The U-factors for typical construction assemblies are included in

Chapter 3 and Appendix A. These values shall be used for all calculations. Where proposed construction

assemblies are not represented in Chapter 3 or Appendix A, values shall be calculated in accordance with

the ASHRAE Handbook of Fundamentals, using the framing factors listed in Appendix A.

For envelope assemblies containing metal framing, the U-factor shall be determined by one of the

following methods:

1. Results of laboratory measurements according to acceptable methods of test.

2. ASHRAE Handbook of Fundamentals where the metal framing is bonded on one or both sides to a

metal skin or covering.

3. The zone method as provided in ASHRAE Handbook of Fundamentals.

4. Effective framing/cavity R-values as provided in Appendix A. When return air ceiling plenums are

employed, the roof/ceiling assembly shall:

a. For thermal transmittance purposes, not include the ceiling proper nor the plenum space as part

of the assembly; and

b. For gross area purposes, be based upon the interior face of the upper plenum surface.

5. Tables in ASHRAE 90.1 Normative Appendix A.

6. Calculation method for steel-framed walls in accordance with Section C402.1.4.1 and Table

C402.1.4.1.

C402.1.5.2 SHGC rate calculations. Fenestration SHGC values for individual components and/or

fenestration are permitted to exceed the SHGC values in Table C402.4 and/or the maximum allowable

fenestration areas in Section C402.4.1 where the proposed total SHGCxA is less than the allowable total

SHGCxA as determined by Equation 4-3.

2018 Washington State Energy Code CE-33

◄

Proposed Total SHGC

A ≤ Allowable Total SHGC

A (Equation 4-3)

Where:

Proposed Total

SHGCxA

SHGCxA-glaz-prop + SHGCxA sky-prop

Allowable Total

SHGCxA

SHGCxA-glaz-allow + SHGCxA-sky-allow

SHGCxA-glaz-prop

Sum of (proposed SHGC

proposed area) for each distinct vertical fenestration

type

SHGCxA-sky-prop

Sum of (proposed SHGC

proposed area) for each distinct skylight type

SHGCxA-glaz-allow

Sum of (code maximum vertical fenestration SHGC from Table C402.4, or

Section C402.4.1.3 if applicable,

proposed area) for each distinct vertical

fenestration type, not to exceed the code maximum area

SHGCxA-sky-allow

Sum of (code maximum skylight SHGC from Table C402.4

proposed area) for

each distinct skylight type, not to exceed the code maximum area

If the proposed vertical fenestration area does not exceed the Vertical Fenestration Area allowed, the target

area for each vertical fenestration type shall equal the proposed area. If the proposed vertical fenestration area

exceeds the Vertical Fenestration Area allowed, the target area of each vertical fenestration element shall be

reduced in the base envelope design by the same percentage and the net area of each above-grade wall type

increased proportionately by the same percentage so that the total vertical fenestration area is exactly equal to

the Vertical Fenestration Area allowed.

If the proposed skylight area does not exceed the Allowable Skylight Area from Section C402.4.1, the target

area shall equal the proposed area. If the proposed skylight area exceeds the Allowable Skylight Area from

Section C402.4.1, the area of each skylight element shall be reduced in the base envelope design by the same

percentage and the net area of each roof type increased proportionately by the same percentage so that the

total skylight area is exactly equal to the allowed percentage per Section C402.3.1 of the gross roof area.

C402.2 Specific building thermal envelope insulation requirements. Insulation in building thermal envelope

opaque assemblies shall comply with Sections C402.2.1 through C402.2.6 and Table C402.1.3.

Where this section refers to installing insulation levels as specified in Section C402.1.3, assemblies complying

with Section C402.1.5 are allowed to install alternate levels of insulation so long as the U-factor of the insulated

assembly is less than or equal to the U-factor required by the respective path.

C402.2.1 Roof assembly. The minimum thermal resistance (R-value) of the insulating material installed either

between the roof framing or continuously on the roof assembly shall be as specified in Table C402.1.3, based

on construction materials used in the roof assembly. Continuous insulation board shall be installed in not less

than 2 layers and the edge joints between each layer of insulation shall be staggered. Insulation installed on a

suspended ceiling with removable ceiling tiles shall not be considered part of the minimum thermal resistance

of the roof insulation.

Exceptions:

1. Continuously insulated roof assemblies where the thickness of insulation varies 1 inch (25 mm) or

less and where the area-weighted U-factor is equivalent to the same assembly with the R-value

specified in Table C402.1.3.

2. Where tapered insulation is used with insulation entirely above deck, those roof assemblies shall

show compliance on a U-factor basis per Section C402.1.4. The effective U-factor shall be determined

through the use of Tables A102.2.6(1), A102.2.6(2) and A102.2.6(3).

3. Two layers of insulation are not required where insulation tapers to the roof deck, such as at roof

drains. At roof drains, the immediate 24” x 24” plan area around each roof drain has a minimum

insulation requirement of R-13, but otherwise is permitted to be excluded from roof insulation area-

weighted calculations.

C402.2.1.1 Skylight curbs. Skylight curbs shall be insulated to the level of roofs with insulation entirely

above deck or R-5, whichever is less.

Exception: Unit skylight curbs included as a component of skylight listed and labeled in accordance with

NFRC 100 shall not be required to be insulated.

CE-34 2018 Washington State Energy Code

C402.2.1.2 Rooftop HVAC equipment curbs. Structural curbs installed to support rooftop HVAC

equipment are allowed to interrupt the above roof insulation. The area under the HVAC equipment inside of

the equipment curb shall be insulated to a minimum of R-13 in all locations where there are not roof

openings for ductwork. The annular space between the roof opening and the ductwork shall be sealed to

maintain the building air barrier. The plan-view area of the HVAC equipment curb shall be excluded from the

prescriptive roof insulation requirements or the area-weighted component performance calculations.

C402.2.2 Reserved.

C402.2.3 Above-grade walls. The minimum thermal resistance (R-value) of materials installed in the wall

cavity between the framing members and continuously on the walls shall be as specified in Table C402.1.3,

based on framing type and construction materials used in the wall assembly. The R-value of integral insulation

installed in concrete masonry units (CMU) shall not be used in determining compliance with Table C402.1.3

except as otherwise noted in the table. In determining compliance with Table C402.1.4, the use of the U-factor

of concrete masonry units with integral insulation shall be permitted.

"Mass walls" where used as a component in the thermal envelope of a building shall comply with one of the

following:

1. Weigh not less than 35 psf (170 kg/m

) of wall surface area.

2. Weigh not less than 25 psf (120 kg/m

) of wall surface area where the material weight is not more than

120 pounds per cubic foot (pcf) (1,900 kg/m

3. Have a heat capacity exceeding 7 Btu/ft

°F (144 kJ/m

K).

4. Have a heat capacity exceeding 5 Btu/ft

x°

F (103 kJ/m

K) where the material weight is not more

than 120 pcf (1900 kg/m

C402.2.4 Below-grade walls. The R-value of the insulating material installed in, or continuously on, the

below-grade walls shall be in accordance with Table C402.1.3. The U-factor or R-value required shall extend

to the level of the lowest floor of the conditioned space enclosed by the below-grade wall.

C402.2.5 Floors. The thermal properties (component R-values or assembly U- or F-factors) of floor

assemblies over outdoor air or unconditioned space shall be as specified in Table C402.1.3 or C402.1.4

based on the construction materials used in the floor assembly. Floor framing cavity insulation or structural

slab insulation shall be installed to maintain permanent contact with the underside of the subfloor decking or

structural slabs.

“Mass floors” where used as a component of the thermal envelope of a building shall provide one of the

following weights:

1. 35 pounds per square foot of floor surface area.

2. 25 pounds per square foot of floor surface area where the material weight is not more than 120 pounds

per cubic foot.

Exceptions:

1. The floor framing cavity insulation or structural slab insulation shall be permitted to be in contact with the

top side of sheathing or continuous insulation installed on the bottom side of floor assemblies where

combined with insulation that meets or exceeds the minimum R-value in Table

C402.1.3 for “Metal framed” or “Wood framed and other” values for “Walls, Above Grade” and extends

from the bottom of the top of all perimeter floor framing or floor assembly members.

2. Insulation applied to the underside of concrete floor slabs shall be permitted an air space of not more

than 1 inch where it turns up and is in contact with the underside of the floor under walls associated with

the building thermal envelope.

C402.2.6 Slabs-on-grade perimeter insulation. Where the slab-on-grade is in contact with the ground, the

minimum thermal resistance (R-value) of the insulation around the perimeter of unheated or heated slab-on-

grade floors designed in accordance with the R-value method of Section C402.1.3 shall be as specified in

Table C402.1.3. The insulation shall be placed on the outside of the foundation or on the inside of the

foundation wall. The insulation shall extend downward from the top of the slab for a minimum distance as

shown in the table or to the top of the footing, whichever is less, or downward to at least the bottom of the slab

and then horizontally to the interior or exterior for the total distance shown in the table. Insulation extending

away from the building shall be protected by pavement or by a minimum of 10 inches (254 mm) of soil.

Insulation complying with Table C402.1.3 shall be provided under the entire area of heated slabs-on-grade.

2018 Washington State Energy Code CE-35

Exception: Where the slab-on-grade floor is greater than 24 inches (61 mm) below the finished exterior

grade, perimeter insulation is not required.

C402.2.7 Airspaces. Where the thermal properties of airspaces are used to comply with this code in

accordance with Section C401.2, such airspaces shall be enclosed in an unventilated cavity constructed to

minimize airflow into and out of the enclosed airspace. Airflow shall be deemed minimized where the enclosed

airspace is located on the interior side of the continuous air barrier and is bounded on all sides by building

components.

Exception: The thermal resistance of airspaces located on the exterior side of the continuous air barrier

and adjacent to and behind the exterior wall covering material shall be determined in accordance with ASTM

C1363 modified with an airflow entering the bottom and exiting the top of the airspace at a minimum air

movement rate of not less than 70 mm/sec.

C402.2.8 Insulation of radiant heating systems. Radiant heating system panels and their associated

components that are installed in interior or exterior assemblies shall be insulated to an R-value of not less

than R-3.5 on all surfaces not facing the space being heated. Radiant heating system panels that are installed

in the building thermal envelope shall be separated from the exterior of the building or unconditioned or

exempt spaces by not less than the R-value of the insulation installed in the opaque assembly in which they

are installed or the assembly shall comply with Section C402.1.4.

Exception: Heated slabs-on-grade insulated in accordance with Section C402.2.6.

C402.3 Reserved.

C402.4 Fenestration. Fenestration shall comply with Sections C402.4 through C402.4.4 and Table C402.4.

Daylight responsive controls shall comply with this section and Section C405.2.4.1.

TABLE C402.4

BUILDING ENVELOPE FENESTRATION MAXIMUM U-FACTOR AND SHGC REQUIREMENTS

CLIMATE

ZONE

5 AND MARINE 4

U-factor for Class AW windows rated in accordance with AAMA/CSA101/I.S.2/A440,

vertical curtain walls and site-built fenestration products

Fixed

U-factor

U-0.38

Operable

U-factor

U-0.40

Entrance doors

U-factor

U-0.60

U-factor for all other vertical fenestration

U-factor

U-0.30

SHGC for all vertical fenestration

Orientation

e,f

SEW

PF < 0.2

0.38

0.51

0.2 ≤ PF < 0.5

0.46

0.56

PF ≥ 0.5

0.61

Skylights

U-factor

U-0.50

SHGC

0.35

a. U-factor and SHGC shall be rated in accordance with NFRC 100.

b. "Fixed" includes curtain wall, storefront, picture windows, and other fixed windows.

c. "Operable" includes openable fenestration products other than "entrance doors."

d. "Entrance door" includes glazed swinging entrance doors. Other doors which are not entrance doors, including sliding

glass doors, are considered "operable."

e. “N” indicates vertical fenestration oriented within 30 degrees of true north. “SEW” indicates orientations other than “N.”

f. Fenestration that is entirely within the conditioned space or is between conditioned and other enclosed space is

exempt from solar heat gain coefficient requirements and not included in the SHGC calculation.

C402.4.1 Maximum area. The total building vertical fenestration area (not including opaque doors and

opaque spandrel panels) shall not exceed 30 percent of the total building gross above-grade wall area. The

skylight area shall not exceed 5 percent of the total building gross roof area (skylight-to-roof ratio).

CE-36 2018 Washington State Energy Code

For buildings with more than one space conditioning category, compliance with the maximum allowed

window-to-wall ratio and skylight-to-roof ratio shall be demonstrated separately for each space conditioning

category. Interior partition ceiling, wall, fenestration and floor areas that separate space conditioning areas shall

not be applied to the window-to-wall ratio and skylight-to-roof ratio calculations.

C402.4.1.1 Vertical fenestration maximum area with high performance alternates. For buildings that

comply with Section C402.4.1.1.1 or C402.4.1.1.2, the total building vertical fenestration area is permitted to

exceed 30 percent but shall not exceed 40 percent of the gross above grade wall area for the purpose of

prescriptive compliance with Section C402.1.4.

When determining compliance using the component performance alternative in accordance with Section

C402.1.5, the total building vertical fenestration area allowed in Equation 4-2 is 40 percent of the above grade

wall area for buildings that comply with the vertical fenestration alternates described in this section.

C402.4.1.1.1 Optimized daylighting. All of the following requirements shall be met:

1. Not less than 50 percent of the total conditioned floor area in the building is within a daylight zone

that includes daylight responsive controls complying with Section C405.2.4.1.

2. Visible transmittance (VT) of all vertical fenestration in the building is greater than or equal to 1.1

times the required solar heat gain coefficient (SHGC) in accordance with Section C402.4, or 0.50,

whichever is greater. It shall be permitted to demonstrate compliance based on the area weighted

average VT being greater than or equal to the area weighted average of the minimum VT

requirements.

Exception: Fenestration that is outside the scope of NFRC 200 is not required to comply with Item 2.

C402.4.1.1.2 High-performance fenestration. All of the following requirements shall be met:

1. All vertical fenestration in the building shall comply with the following U-factors:

a. U-factor for Class AW windows rated in accordance with AAMA/CSA101/I.S.2/A440, vertical

curtain walls and site-built fenestration products (fixed) = 0.34

b. U-factor for Class AW windows rated in accordance with AAMA/CSA101/I.S.2/A440, vertical

curtain walls and site-built fenestration products (operable) = 0.36

c. Entrance doors = 0.60

d. U-factor for all other vertical fenestration = 0.28

2. The SHGC of the vertical fenestration shall be less than or equal to 0.35, adjusted for projection

factor in compliance with C402.4.3.

An area-weighted average shall be permitted to satisfy the U-factor requirement for each fenestration

product category listed in Item 1 of this section. Individual fenestration products from different fenestration

product categories shall not be combined in calculating the area-weighted average U-factor.

C402.4.2 Minimum skylight fenestration area. For buildings with single story enclosed spaces greater than

2,500 square feet (232 m

) in floor area that are directly under a roof and have a ceiling height greater than 15

feet (4572 mm) for no less than 75 percent of the ceiling area; these single-story spaces shall be provided with

skylights and daylight responsive controls in accordance with Section C405.2.4. Space types required to comply

with this provision include office, lobby, atrium, concourse, corridor, gymnasium/exercise center, convention

center, automotive service, manufacturing, nonrefrigerated warehouse, retail store, distribution/sorting area,

transportation, and workshop. Skylights in these spaces are required to provide a total toplit zone area not less

than 50 percent of the floor area and shall provide one of the following:

1. A minimum ratio of skylight area to toplit zone area of not less than 3 percent where all skylights have a

VT of at least 0.40 as determined in accordance with Section C303.1.3

2. A minimum skylight effective aperture of at least 1 percent determined in accordance with Equation 4-5.

Skylight Effective Aperture = (0.85 x Skylight Area x Skylight VT x WF)

Toplit zone

where:

Skylight area = Total fenestration area of skylights.

Skylight VT = Area weighted average visible transmittance of skylights.

WF = Area weighted average well factor, where well factor is 0.9 if light well depth is less than 2

feet (610 mm), or 0.7 if light well depth is 2 feet (610 mm) or greater, or 1.0 for tubular

daylighting devices with VT-annual ratings measured according to NFRC 203.

Light well depth = Measure vertically from the underside of the lowest point of the skylight glazing to the

ceiling plane under the skylight.

(Equation 4-5)

2018 Washington State Energy Code CE-37

Exceptions:

1. Skylights above daylight zones of enclosed spaces are not required in:

1.1. Reserved.

1.2. Spaces where the designed general lighting power densities are less than 0.5 W/ft

(5.4 W/m

)

and at least 10 percent lower than the lighting power allowance in Section C405.4.2.

1.3. Areas where it is documented that existing structures or natural objects block direct beam

sunlight on at least half of the roof over the enclosed area for more than 1,500 daytime hours per

year between 8 a.m. and 4 p.m.

1.4. Spaces where the daylight zone under rooftop monitors is greater than 50 percent of the

enclosed space floor area.

1.5. Spaces where the total floor area minus the sidelit zone area is less than 2,500 square feet (232

), and where the lighting in the daylight zone is controlled in accordance with Section

C405.2.3.1.

2. The skylight effective aperture, calculated in accordance with Equation 4-5, is permitted to be 0.66

percent in lieu of one percent if the VT-annual of the skylight or TDD, as measured by NFRC 203, is

greater than 38 percent.

C402.4.2.1 Lighting controls in daylight zones under skylights. Daylight responsive controls complying

with Section C405.2.4.1 shall be provided to control all electric lights within toplit zones.

C402.4.2.2 Haze factor. Skylights in office, storage, automotive service, manufacturing, nonrefrigerated

warehouse, retail store, and distribution/sorting area spaces shall have a glazing material or diffuser with a

haze factor greater than 90 percent when tested in accordance with ASTM D 1003.

Exception: Skylights designed and installed to exclude direct sunlight entering the occupied space by the

use of fixed or automated baffles, or the geometry of skylight and light well.

C402.4.2.3 Daylight zones. Daylight zones referenced in Sections C402.4.1.1 through C402.4.2.2 shall

comply with Section C405.2.4.2 and C405.2.4.3, as applicable. Daylight zones shall include toplit zones and

sidelit zones.

C402.4.3 Maximum U-factor and SHGC. The maximum U-factor and solar heat gain coefficient (SHGC) for

fenestration shall be as specified in Table C402.4.

The window projection factor shall be determined in accordance with Equation 4-6.

PF = A/B

Where:

PF = Projection factor (decimal).

A = Distance measured horizontally from the furthest continuous extremity of any overhang, eave, or

permanently attached shading device to the vertical surface of the glazing.

B = Distance measured vertically from the bottom of the glazing to the underside of the overhang, eave,

or permanently attached shading device.

Where different windows or glass doors have different PF values, they shall each be evaluated separately.

C402.4.3.1 Reserved

C402.4.3.2 Reserved.

C402.4.3.3 Dynamic glazing. Where dynamic glazing is intended to satisfy the SHGC and VT requirements

of Table C402.4, the ratio of the higher to lower labeled SHGC shall be greater than or equal to 2.4, and the

dynamic glazing shall be automatically controlled to modulate the amount of solar gain into the space in

multiple steps. Dynamic glazing shall be considered separately from other fenestration, and area-weighted

averaging with other fenestration that is not dynamic glazing shall not be permitted.

Exception: Dynamic glazing is not required to comply with this section where both the lower and higher

labeled SHGC already comply with the requirements of Table C402.4.

C402.4.3.4 Area-weighted U-factor. An area-weighted average shall be permitted to satisfy the U-factor

requirements for each fenestration product category listed in Table C402.4. Individual fenestration products

from different fenestration product categories listed in Table C402.4 shall not be combined in calculating

area-weighted average U-factor.

(Equation 4-6)

CE-38 2018 Washington State Energy Code

C402.4.4 Doors. Opaque swinging doors shall comply with Table C402.1.4. Opaque non-swinging doors shall

comply with Table C402.1.3. Opaque doors shall be considered part of the gross area of above grade walls

that are part of the building thermal envelope. Other doors shall comply with the provisions of Section

C402.4.3 for vertical fenestration and the entire door area, including the frame, shall be considered part of the

fenestration area of the building thermal envelope.

C402.5 Air leakage – thermal envelope. The thermal envelope of buildings shall comply with Sections

C402.5.1 through C402.5.8.

C402.5.1 Air barriers. A continuous air barrier shall be provided throughout the building thermal envelope.

The air barriers shall be permitted to be located on the inside or outside of the building envelope, located

within the assemblies composing the envelope, or any combination thereof. The air barrier shall comply with

Sections C402.5.1.1 and C402.5.1.2.

C402.5.1.1 Air barrier construction. The continuous air barrier shall be constructed to comply with the

following:

1. The air barrier shall be continuous for all assemblies that are the thermal envelope of the building and

across the joints and assemblies.

2. Air barrier joints and seams shall be sealed, including sealing transitions in places and changes in

materials. The joints and seals shall be securely installed in or on the joint for its entire length so as

not to dislodge, loosen or otherwise impair its ability to resist positive and negative pressure from

wind, stack effect and mechanical ventilation.

3. Penetrations of the air barrier shall be caulked, gasketed or otherwise sealed in a manner compatible

with the construction materials and location. Sealing shall allow for expansion, contraction and

mechanical vibration. Joints and seams associated with penetrations shall be sealed in the same

manner or taped. Sealing materials shall be securely installed around the penetrations so as not to

dislodge, loosen or otherwise impair the penetrations’ ability to resist positive and negative pressure

from wind, stack effect, and mechanical ventilation. Sealing of concealed fire sprinklers, where

required, shall be in a manner that is recommended by the manufacturer. Caulking or other adhesive

sealants shall not be used to fill voids between fire sprinkler cover plates and walls or ceilings.

4. Recessed lighting fixtures shall comply with Section C402.5.8. Where similar objects are installed

which penetrate the air barrier, provisions shall be made to maintain the integrity of the air barrier.

5. Construction documents shall contain a diagram showing the building’s pressure boundary in plan(s)

and section(s) and a calculation of the area of the pressure boundary to be considered in the test.

C402.5.1.2 Building test. The completed building shall be tested and the air leakage rate of the building

envelope shall not exceed 0.25 cfm/ft

at a pressure differential of 0.3 inches water gauge (2.0 L/s

75 Pa) at the upper 95 percent confidence interval in accordance with ASTM E 779 or an equivalent method

approved by the code official. A report that includes the tested surface area, floor area, air by volume,

stories above grade, and leakage rates shall be submitted to the building owner and the code official. If the

tested rate exceeds that defined here by up to 0.15 cfm/ft

, a visual inspection of the air barrier shall be

conducted and any leaks noted shall be sealed to the extent practicable. An additional report identifying the

corrective actions taken to seal air leaks shall be submitted to the building owner and the Code Official and

any further requirement to meet the leakage air rate will be waived. If the tested rate exceeds 0.40 cfm/ft

corrective actions must be made and the test completed again. A test above 0.40 cfm/ft

will not be

accepted.

1. Test shall be accomplished using either (1) both pressurization and depressurization or (2)

pressurization alone, but not depressurization alone. The test results shall be plotted against the

correct P for pressurization in accordance with Section 9.4 of ASTM E779.

2. The test pressure range shall be from 25 Pa to 80 Pa per Section 8.10 of ASTM E779, but the upper

limit shall not be less than 50 Pa, and the difference between the upper and lower limit shall not be

less than 25 Pa.

3. If the pressure exponent n is less than 0.45 or greater than 0.85 per Section 9.6.4 of ASTM E779, the

test shall be rerun with additional readings over a longer time interval.

2018 Washington State Energy Code CE-39

C402.5.1.2.1 Building test for mixed-use buildings. Where a building is three or fewer stories above

grade plane and contains both commercial and residential uses, the air barrier of the R-2 and R-3

occupancy areas of the building is permitted to be separately tested according to Section R402.4.1.2.

Alternatively, it is permissible to test the air barrier of the entire building according to Section C402.5.1.2,

provided that the tested air leakage rate does not exceed the rate specified in Section C402.5.1.2.

C402.5.2 Reserved.

C402.5.3 Rooms containing fuel-burning appliances. Where combustion air is supplied through openings

in an exterior wall to a room or space containing a space conditioning fuel-burning appliance, one of the

following shall apply:

1. The room or space containing the appliance shall be located outside of the building thermal envelope.

2. The room or space containing the appliance shall be enclosed and isolated from conditioned spaces

inside the building thermal envelope. Such rooms shall comply with all of the following:

2.1. The walls, floor and ceiling that separate the enclosed room or space from the conditioned spaces

shall be insulated to be at least equivalent to the insulation requirement of below grade walls as

specified in Table C402.1.3 or C402.1.4.

2.2. The walls, floors and ceiling that separate the enclosed room or space from conditioned spaces

shall be sealed in accordance with Section C402.5.1.1

2.3. The doors into the enclosed room or space shall be fully gasketed.

2.4. Water lines and ducts in the enclosed room or space shall be insulated in accordance with Section

C403.

2.5. Where the air duct supplying combustion air to the enclosed room or space passes through

conditioned space, the duct shall be insulated to an R-value of not less than R-8.

Exception: Fireplaces and stoves complying with Sections 901 through 905 of the International Mechanical

Code, and Section 2111.13 of the International Building Code.

C402.5.4 Doors and access openings to shafts, chutes, stairways, and elevator lobbies. Doors and

access openings from conditioned space to shafts, chutes, stairways and elevator lobbies shall be gasketed,

weatherstripped or sealed.

Exceptions:

1. Door openings required to comply with Section 716 of the International Building Code.

2. Doors and door openings required to comply with UL 1784 by the International Building Code.

C402.5.5 Air intakes, exhaust openings, stairways and shafts. Stairway enclosures, elevator shaft vents

and other outdoor air intake and exhaust openings integral to the building envelope shall be provided with

dampers in accordance with Section C403.7.9.

C402.5.6 Loading dock weatherseals. Cargo door openings and loading dock door openings shall be

equipped with weatherseals that restrict infiltration and provide direct contact along the top and sides of

vehicles that are parked in the doorway.

C402.5.7 Vestibules. All building entrances shall be protected with an enclosed vestibule, with all doors

opening into and out of the vestibule equipped with self-closing devices. Vestibules shall be designed so that

in passing through the vestibule it is not necessary for the interior and exterior doors to open at the same time.

The installation of one or more revolving doors in the building entrance shall not eliminate the requirement that

a vestibule be provided on any doors adjacent to revolving doors. For the purposes of this section, “building

entrances” shall include exit-only doors in buildings where separate doors for entering and exiting are

provided.

Interior and exterior doors shall have a minimum distance between them of not less than 7 feet. The exterior

envelope of conditioned vestibules shall comply with the requirements for a conditioned space. Either the

interior or exterior envelope of unconditioned vestibules shall comply with the requirements for a conditioned

space. The building lobby is not considered a vestibule.

Exception: Vestibules are not required for the following:

1. Doors not intended to be used as building entrances.

2. Unfinished ground-level space greater than 3,000 square feet (298 m

) if a note is included on the

permit documents at each exterior entrance to the space stating “Vestibule required at time of tenant

build-out if entrance serves a space greater than 3,000 square feet in area.”

CE-40 2018 Washington State Energy Code

3. Doors opening directly from a sleeping unit or dwelling unit.

4. Doors between an enclosed space smaller than 3,000 square feet (298 m2) in area and the exterior of

the building or the building entrance lobby, where those doors do not comprise one of the primary

building entrance paths to the remainder of the building. The space must be enclosed and separated

without transfer air paths from the primary building entrance paths. If there are doors between the

space and the primary entrance path then the doors shall be equipped with self-closing devices so the

space acts as a vestibule for the primary building entrance.

5. Revolving doors.

6. Doors used primarily to facilitate vehicular movement or material handling and adjacent personnel

doors.

7. In buildings less than three stories above grade or in spaces that do not directly connect with the

building elevator lobby, doors that have an air curtain with a velocity of not less than 6.56 feet per

second (2 m/s) at the floor that have been tested in accordance with ANSI/AMCA 220 and installed in

accordance with the manufacturer’s instructions. Manual or automatic controls shall be provided that

will operate the air curtain with the opening and closing of the door. Air curtains and their controls

shall comply with Section C408.2.3

8. Building entrances in buildings that are less than four stories above grade and less than 10,000

square feet in area.

9. Elevator doors in parking garages provided that the elevators have an enclosed lobby at each level of

the garage.

10. Entrances to semi-heated spaces.

C402.5.8 Recessed lighting. Recessed luminaires installed in the building thermal envelope shall be all of

the following:

1. IC Rated.

2. Labeled as having an air leakage rate of not more than 2.0 cfm (0.944 L/s) when tested in accordance

with ASTM E 283 at a 1.57 psf (75 Pa) pressure differential.

3. Sealed with a gasket or caulk between the housing and interior wall or ceiling covering.

SECTION C403

MECHANICAL SYSTEMS

C403.1 General. Mechanical systems and equipment serving heating, cooling, ventilating, and other needs shall

comply with this section.

Exceptions:

1. Energy using equipment used by a manufacturing, industrial or commercial process other than for

conditioning spaces or maintaining comfort and amenities for the occupants and not otherwise regulated

by C403.3.2, Tables C403.3.2(1) through (12) inclusive, C403.7.7, C403.9.2.1, C403.10.3, C403.11.2,

C403.11.3, C404.2, Table C404.2, C405.8, and C410. Data center and computer room HVAC

equipment is not covered by this exception.

2. Data center systems are exempt from Sections C403.4 and C403.5.

C403.1.1 HVAC total system performance ratio (HVAC TSPR). For systems serving office, retail, library

and education occupancies and buildings, which are subject to the requirements of Section C403.3.5 without

exceptions, the HVAC total system performance ratio (HVAC TSPR) of the proposed design HVAC system

shall be more than or equal to the HVAC TSPR of the standard reference design as calculated according to

Appendix D, Calculation of HVAC Total System Performance Ratio.

Exceptions:

1. Buildings with conditioned floor area less than 5,000 square feet.

2. HVAC systems using district heating water, chilled water or steam.

3. HVAC systems not included in Table D601.11.1.

4. HVAC systems with chilled water supplied by absorption chillers, heat recovery chillers, water to

water heat pumps, air to water heat pumps, or a combination of air and water cooled chillers on the

same chilled water loop.

5. HVAC system served by heating water plants that include air to water or water to water heat pumps.

2018 Washington State Energy Code CE-41

6. Underfloor air distribution HVAC systems.

7. Space conditioning systems that do not include mechanical cooling.

8. Alterations to existing buildings that do not substantially replace the entire HVAC system.

9. HVAC systems meeting all the requirements of the standard reference design HVAC system in

Table D602.11, Standard Reference Design HVAC Systems.

C403.1.2 Calculation of heating and cooling loads. Design loads associated with heating, ventilating and

air conditioning of the building shall be determined in accordance with the procedures described in

ANSI/ASHRAE/ACCA Standard 183 or by an approved equivalent computational procedure, using the design

parameters specified in Chapter 3. Heating and cooling loads shall be adjusted to account for load reductions

that are achieved where energy recovery systems are utilized in the HVAC system in accordance with the

ASHRAE HVAC Systems and Equipment Handbook by an approved equivalent computational procedure.

C403.1.3 Data centers. Data center systems shall comply with Sections 6 and 8 of ASHRAE Standard 90.4,

with the following changes:

1. Replace design MLC in ASHRAE Standard 90.4 Table 6.2.1.1 “Maximum Design Mechanical Load

Component (Design MLC)” with the following per applicable climate zone:

Zone 4C Design MLC = 0.22 Zone 5B Design MLC = 0.24

2. Replace annualized MLC values of Table 6.2.1.2 “Maximum Annualized Mechanical Load Component

(Annualized MLC)” in ASHRAE Standard 90.4 with the following per applicable climate zone:

Zone 4C Annual MLC = 0.18 Zone 5B Annual MLC = 0.17

C403.2 System design. Mechanical systems shall be designed to comply with Sections C403.2.1 and

C403.2.2. Where elements of a building’s mechanical systems are addressed in Sections C403.3 through

C403.13, such elements shall comply with the applicable provisions of those sections.

C403.2.1 Zone isolation required. HVAC systems serving zones that are intended to operate or be

occupied nonsimultaneously shall be divided into isolation areas. Zones may be grouped into a single

isolation area provided it does not exceed 25,000 square feet (2323 m

) of conditioned floor area nor

include more than one floor. Each isolation area shall be equipped with isolation devices and controls

configured to automatically shut off the supply of conditioned air and outdoor air to and exhaust air from the

isolation area. Each isolation area shall be controlled independently by a device meeting the requirements

of Section C403.4.2.2. Central systems and plants shall be provided with controls and devices that will allow

system and equipment operation for any length of time while serving only the smallest isolation area served

by the system or plant.

Exceptions:

1. Exhaust air and outdoor air connections to isolation areas where the fan system to which they

connect is not greater than 5,000 cfm (2360 L/s).

2. Exhaust airflow from a single isolation area of less than 10 percent of the design airflow of the

exhaust system to which it connects.

3. Isolation areas intended to operate continuously or intended to be inoperative only when all other

isolation areas in a zone are inoperative.

C403.2.2 Ventilation and exhaust.

C403.2.2.1 Ventilation. Ventilation, either natural or mechanical, shall be provided in accordance with

Chapter 4 of the International Mechanical Code. Where mechanical ventilation is provided, the system

shall be configured to provide no greater than 150 percent of the minimum outdoor air required by Chapter

4 of the International Mechanical Code or other applicable code or standard, whichever is greater.

Exceptions:

1. The mechanical system may supply outdoor air at rates higher than the limit above when it is

used for particulate or VOC dilution, economizer, night flushing, dehumidification, pressurization,

exhaust make-up, or other process air delivery. Outdoor air shall be reduced to the minimum

ventilation rates when not required for the preceding uses.

2. Air systems supplying Group R-1, R-2 or I-2 occupancies.

3. Alterations that replace less than half of the total heating and cooling capacity of the system.

CE-42 2018 Washington State Energy Code

4. Systems with energy recovery complying with the requirements of Section C403.7.6 that utilize

sensible only active chilled beams for space cooling without any additional zonal fan power.

Active chilled beams shall be permitted to utilize the increased outdoor airflow to increase space

sensible capacity and to maintain space latent cooling loads without additional controls to reduce

the outdoor airflow to each zone.

C403.2.2.2 Exhaust. Exhaust shall be provided in accordance with Chapters 4 and 5 of the International

Mechanical Code. Where exhaust is provided, the system shall be configured to provide no greater than

150 percent of the minimum exhaust air required by Chapters 4 and 5 of the International Mechanical

Code or other applicable code or standard, whichever is greater.

Exceptions:

1. The mechanical system may exhaust air at rates higher than the limit above when it is used for

particulate or VOC dilution, economizer, night flushing, dehumidification, pressure equalization,

relief, or other process exhaust air requirements. Outdoor air and exhaust air shall be reduced to

the minimum exhaust rates when not required for the preceding uses.

2. Domestic range hood exhaust in Group R occupancies.

3. Exhaust for Group I occupancies.

C403.2.3 Variable flow capacity. For fan and pump motors 7.5 hp and greater including motors in or

serving custom and packaged air handlers serving variable air volume fan systems, constant volume fans,

heating and cooling hydronic pumping systems, pool and service water pumping systems, domestic water

pressure-booster systems, cooling tower fan, and other pump or fan motors where variable flows are

required, there shall be:

1. Variable speed drives; or

2. Other controls and devices that will result in fan and pump motor demand of no more than 30 percent of

design wattage at 50 percent of design air volume for fans when static pressure set point equals 1/3 the

total design static pressure, and 50 percent of design water flow for pumps, based on manufacturer's

certified test data. Variable inlet vanes, throttling valves (dampers), scroll dampers or bypass circuits

shall not be allowed.

Exception: Variable speed devices are not required for motors that serve:

1. Fans or pumps in packaged equipment where variable speed drives are not available as a factory

option from the equipment manufacturer.

2. Fans or pumps that are required to operate only for emergency fire-life-safety events (e.g., stairwell

pressurization fans, elevator pressurization fans, fire pumps, etc.).

C403.3 Equipment selection. Heating and cooling equipment installed in mechanical systems shall be sized in

accordance with Section C403.3.1 and shall be not less efficient in the use of energy than as specified in

Section C403.3.2.

C403.3.1 Equipment and system sizing. The output capacity of heating and cooling equipment shall be not

greater than that of the smallest available equipment size that exceeds the loads calculated in accordance

with Section C403.1.2. A single piece of equipment providing both heating and cooling shall satisfy this

provision for one function with the capacity for the other function as small as possible, within available

equipment options.

Exceptions:

1. Required standby equipment and systems provided with controls and devices that allow such systems

or equipment to operate automatically only when the primary equipment is not operating.

2. Multiple units of the same equipment type with combined capacities exceeding the design load and

provided with controls that are configured to sequence the operation of each unit based on load.

C403.3.2 HVAC equipment performance requirements. Equipment shall meet the minimum efficiency

requirements of Tables C403.3.2(1) through C403.3.2(12) when tested and rated in accordance with the

applicable test procedure. Plate-type liquid-to-liquid heat exchangers shall meet the minimum requirements of

Table C403.3.2(10). The efficiency shall be verified through certification and listed under an approved

certification program or, if no certification program exists, the equipment efficiency ratings shall be supported

by data furnished by the manufacturer. Where multiple rating conditions or performance requirements are

provided, the equipment shall satisfy all stated requirements. Where components, such as indoor or outdoor

2018 Washington State Energy Code CE-43

coils, from different manufacturers are used, calculations and supporting data shall be furnished by the

designer that demonstrates that the combined efficiency of the specified components meets the requirements

herein.

Gas-fired and oil-fired forced air furnaces with input ratings of 225,000 Btu/h (65 kW) or greater and all unit

heaters shall also have an intermittent ignition or interrupted device (IID), and have either mechanical draft

(including power venting) or a flue damper. A vent damper is an acceptable alternative to a flue damper for

furnaces where combustion air is drawn from the conditioned space. All furnaces with input ratings of 225,000

Btu/h (65 kW) or greater, including electric furnaces, that are not located within the conditioned space shall

have jacket losses not exceeding 0.75 percent of the input rating.

C403.3.2.1 Chillers. Chilled water plants and buildings with more than 500 tons total capacity shall not have

more than 100 tons provided by air-cooled chillers.

Exceptions:

1. Where the designer demonstrates that the water quality at the building site fails to meet

manufacturer's specifications for the use of water-cooled equipment.

2. Air-cooled chillers with minimum efficiencies at least 10 percent higher than those listed in Table

C403.3.2(7).

3. Replacement of existing air-cooled chiller equipment.

4. Air-to-water heat pump units that are configured to provide both heating and cooling and that are

rated in accordance with AHRI 550/590. Where the air-to-water heat pumps are designed for a

maximum supply leaving water temperature of less than 140°F, the efficiency rating will be calculated

and reported at the maximum unit leaving water temperature for this test condition.

TABLE C403.3.2(1)A

MINIMUM EFFICIENCY REQUIREMENTS:

ELECTRICALLY OPERATED UNITARY AIR CONDITIONERS AND CONDENSING UNITS

EQUIPMENT TYPE

SIZE

CATEGORY

UNITS

PATH A

PATH B

TEST

PROCEDURE

FULL

LOAD

IPLV

FULL

LOAD

IPLV

Air-cooled chillers

< 150 tons

EER

≥ 10.100

≥ 13.700

≥ 9.700

≥ 15.800

AHRI 550/590

≥ 150 tons

EER

≥ 10.100

≥ 14.000

≥ 9.700

≥ 16.100

Air cooled without

condenser, electrical

operated

All capacities

EER

Air-cooled chillers without condensers shall be

rated with matching condensers and comply with

the air-cooled chiller efficiency requirements

Water cooled,

electrically operated,

positive displacement

< 75 tons

kW/ton

≤ 0.750

≤ 0.600

≤ 0.780

≤ 0.500

≥ 75 tons and

< 150 tons

kW/ton

≤ 0.720

≤ 0.560

≤ 0.750

≤ 0.490

≥ 150 tons and

< 300 tons

kW/ton

≤ 0.660

≤0.540

≤ 0.680

≤ 0.440

≥ 300 tons and

< 600 tons

kW/ton

≤ 0.610

≤ 0.520

≤ 0.625

≤ 0.410

≥ 600 tons

kW/ton

≤ 0.560

≤ 0.500

≤ 0.585

≤ 0.380

Water cooled,

electrically operated,

centrifugal

< 150 tons

kW/ton

≤ 0.610

≤ 0.550

≤ 0.695

≤ 0.440

≥ 150 tons and

< 300 tons

kW/ton

≤ 0.610

≤ 0.550

≤ 0.695

≤ 0.400

≥300 tons and

< 400 tons

kW/ton

≤ 0.560

≤ 0.520

≤ 0.595

≤ 0.390

≥400 tons

kW/ton

≤0.560

≤ 0.500

≤ 0.585

≤0.380

Air cooled, absorption

single effect

All capacities

COP

≥ 0.600

AHRI 560

Water cooled,

absorption single effect

All capacities

COP

≥ 0.700

Absorption double

effect, indirect fired

All capacities

COP

≥ 1.000

≥ 1.050

Absorption double

effect, direct fired

All capacities

COP

≥ 1.000

For SI: 1 ton = 3517 W, 1 British thermal unit per hour = 0.2931 W, °C = [(°F) - 32]/1.8.

NA = Not applicable, not to be used for compliance; NR = No requirement.

a. The centrifugal chiller equipment requirements, after adjustment in accordance with Section C403.3.2.2 or Section C403.3.2.3, do not

apply to chillers used in low-temperature applications where the design leaving fluid temperature is less than 36ºF. The requirements

do not apply to positive displacement chillers with leaving fluid temperatures less than or equal to 32ºF. The requirements do not apply

to absorption chillers with design leaving fluid temperatures less than 40ºF.

b. Compliance with this standard can be obtained by meeting the minimum requirements of Path A or B. However, both the full load and

IPLV shall be met to fulfill the requirements of Path A or B.

c. Chapter 12 of the referenced standard contains a complete specification of the referenced test procedure, including the referenced

year version of the test procedure.

CE-52 2018 Washington State Energy Code

TABLE C403.3.2(8)

MINIMUM EFFICIENCY REQUIREMENTS:

HEAT REJECTION EQUIPMENT

EQUIPMENT TYPE

TOTAL SYSTEM

HEAT REJECTION

CAPACITY AT

RATED

CONDITIONS

SUBCATEGORY OR RATING

CONDITION

PERFORMANCE

REQUIRED

b, c, d, g, h

TEST

PROCEDURE

e f

Propeller or axial fan

open circuit cooling

towers

All

95°F Entering Water

85°F Leaving Water

75°F Entering wb

≥ 40.2 gpm/hp

CTI ATC-105 and

CTI STD-201 RS

Centrifugal fan open

circuit cooling towers

All

95°F Entering Water

85°F Leaving Water

75°F Entering wb

≥ 20.0 gpm/hp

CTI ATC-105 and

CTI STD-201 RS

Propeller or axial fan

closed circuit cooling

towers

All

102°F Entering Water

90°F Leaving Water

75°F Entering wb

≥ 16.1 gpm/hp

CTI ATC-105S and

CTI STD-201 RS

Centrifugal closed circuit

cooling towers

All

102°F Entering Water

90°F Leaving Water

75°F Entering wb

≥ 7.0 gpm/hp

CTI ATC-105S and

CTI STD-201 RS

Propeller or axial fan

evaporative condensers

All

R-507A Test Fluid

165°F Entering Gas Temperature

105°F Condensing Temperature

75°F Entering wb

≥ 157,000 Btu/h•hp

CTI ATC-106

Propeller or axial fan

evaporative condensers

All

Ammonia Test Fluid

140°F Entering Gas Temperature

96.3°F Condensing Temperature

75°F Entering wb

≥ 134,000 Btu/h•hp

CTI ATC-106

Centrifugal fan

evaporative condensers

All

R-507A Test Fluid

165°F Entering Gas Temperature

105°F Condensing Temperature

75°F Entering wb

≥ 135,000 Btu/h•hp

CTI ATC-106

Centrifugal fan

evaporative condensers

All

Ammonia Test Fluid

140°F Entering Gas Temperature

96.3°F Condensing Temperature

75°F Entering wb

≥ 110,000 Btu/h•hp

CTI ATC-106

Air-cooled condensers

All

125°F Condensing Temperature

R-22 Test Fluid

190°F Entering Gas Temperature

15°F Subcooling

95°F Entering db

≥ 176,000 Btu/h·hp

AHRI 460

For SI: °C = [(°F)-32]/1.8, L/s · kW = (gpm/hp)/(11.83), COP = (Btu/h · hp)/(2550.7).

db = dry bulb temperature, °F, wb = wet bulb temperature, °F.

a. The efficiencies and test procedures for both open and closed circuit cooling towers are not applicable to hybrid cooling towers that

contain a combination of wet and dry heat exchange sections.

b. For purposes of this table, open circuit cooling tower performance is defined as the water flow rating of the tower at the thermal rating

condition divided by the fan nameplate rated motor power.

c. For purposes of this table, closed circuit cooling tower performance is defined as the water flow rating of the tower at the thermal rating

condition divided by the sum of the fan nameplate rated motor power and the spray pump nameplate rated motor power.

d. For purposes of this table, air-cooled condenser performance is defined as the heat rejected from the refrigerant divided by the fan

nameplate rated motor power.

e. Chapter 12 of the referenced standard contains a complete specification of the referenced test procedure, including the referenced

year version of the test procedure.

f. Where a certification program exists for a covered product, and it includes provisions for verification and challenge of equipment

efficiency ratings, then the product shall be listed in the certification program, or, if a certification program exists for a covered product,

and it includes provisions for verification and challenge of equipment efficiency ratings, but the product is not listed in the existing

certification program, the ratings shall be verified by an independent laboratory test report.

g. Cooling towers shall comply with the minimum efficiency listed in the table for that specific type of tower with the capacity effect of any

project-specific accessories and/or options included in the capacity of the cooling tower.

h. For purposes of this table, evaporative condenser performance is defined as the heat rejected at the specified rating condition in the

table, divided by the sum of the fan motor nameplate power and the integral spray pump nameplate power.

i. Requirements for evaporative condensers are listed with ammonia (R-717) and R-507A as test fluids in this table. Evaporative

condensers intended for use with halocarbon refrigerants other than R-507A must meet the minimum efficiency requirements listed

above with R-507A as the test fluid.

2018 Washington State Energy Code CE-53

TABLE C403.3.2(9)

MINIMUM EFFICIENCY REQUIREMENTS:

AIR CONDITIONERS AND CONDENSING UNITS SERVING

COMPUTER ROOMS AND DATA CENTERS

Equipment

Type

Net Sensible

Cooling Capacity

Standard Model

Minimum Net Sensible COP

Test Procedure

Return Air Dry-Bulb Temperature/

Dew-Point Temperature

Class 1

Class 2

Class 3

75°F/52°F

85°F/52°F

95°F/52°F

Air cooled

<65,000 Btu/h

Downflow unit

2.30

AHRI 1360

Upflow unit—ducted

2.10

Upflow unit—unducted

2.09

Horizontal-flow unit

2.45

≥ 65,000 Btu/h and

< 240,000 Btu/h

Downflow unit

2.20

Upflow unit—ducted

2.05

Upflow unit—unducted

1.99

Horizontal-flow unit

2.35

≥ 240,000 Btu/h

Downflow unit

2.00

Upflow unit—ducted

1.85

Upflow unit—unducted

1.79

Horizontal-flow unit

2.15

Water cooled

<65,000 Btu/h

Downflow unit

2.50

AHRI 1360

Upflow unit—ducted

2.30

Upflow unit—unducted

2.25

Horizontal-flow unit

2.70

≥ 65,000 Btu/h and

< 240,000 Btu/h

Downflow unit

2.40

Upflow unit—ducted

2.20

Upflow unit—unducted

2.15

Horizontal-flow unit

2.60

≥ 240,000 Btu/h

Downflow unit

2.25

Upflow unit—ducted

2.10

Upflow unit—unducted

2.05

Horizontal-flow unit

2.45

Water cooled

with fluid

economizer

<65,000 Btu/h

Downflow unit

2.45

AHRI 1360

Upflow unit—ducted

2.25

Upflow unit—unducted

2.20

Horizontal-flow unit

2.60

≥ 65,000 Btu/h and

< 240,000 Btu/h

Downflow unit

2.35

Upflow unit—ducted

2.15

Upflow unit—unducted

2.10

Horizontal-flow unit

2.55

≥ 240,000 Btu/h

Downflow unit

2.20

Upflow unit—ducted

2.05

Upflow unit—unducted

2.00

Horizontal-flow unit

2.40

CE-54 2018 Washington State Energy Code

TABLE C403.3.2(9) (continued)

MINIMUM EFFICIENCY REQUIREMENTS:

AIR CONDITIONERS AND CONDENSING UNITS SERVING

COMPUTER ROOMS AND DATA CENTERS

Equipment

Type

Net Sensible

Cooling Capacity

Standard Model

Minimum Net Sensible COP

Test Procedure

Return Air Dry-Bulb Temperature/

Dew-Point Temperature

Class 1

Class 2

Class 3

75°F/52°F

85°F/52°F

95°F/52°F

Glycol cooled

<65,000 Btu/h

Downflow unit

2.30

AHRI 1360

Upflow unit—ducted

2.10

Upflow unit—unducted

2.00

Horizontal-flow unit

2.40

≥ 65,000 Btu/h and

< 240,000 Btu/h

Downflow unit

2.05

Upflow unit—ducted

1.85

Upflow unit—unducted

1.85

Horizontal-flow unit

2.15

≥ 240,000 Btu/h

Downflow unit

1.95

Upflow unit—ducted

1.80

Upflow unit—unducted

1.75

Horizontal-flow unit

2.10

Glycol cooled

with fluid

economizer

<65,000 Btu/h

Downflow unit

2.25

AHRI 1360

Upflow unit—ducted

2.10

Upflow unit—unducted

2.00

Horizontal-flow unit

2.35

≥ 65,000 Btu/h and

< 240,000 Btu/h

Downflow unit

1.95

Upflow unit—ducted

1.80

Upflow unit—unducted

1.75

Horizontal-flow unit

2.10

≥ 240,000 Btu/h

Downflow unit

1.90

Upflow unit—ducted

1.80

Upflow unit—unducted

1.70

Horizontal-flow unit

2.10

TABLE C403.3.2(10)

MINIMUM EFFICIENCY REQUIREMENTS: HEAT TRANSFER EQUIPMENT

EQUIPMENT TYPE

SUBCATEGORY

MINIMUM EFFICIENCY

TEST PROCEDURE

Liquid-to-liquid heat exchangers

Plate type

AHRI 400

NR = No Requirement

a. Chapter 12 of the referenced standard contains a complete specification of the referenced test procedure, including the referenced

year version of the test procedure.

2018 Washington State Energy Code CE-55

TABLE C403.3.2(11)

MINIMUM EFFICIENCY REQUIREMENTS: ELECTRICALLY OPERATED DX-DOAS UNITS, SINGLE-

PACKAGE AND REMOTE CONDENSER, WITHOUT ENERGY RECOVERY

EQUIPMENT TYPE

SUBCATEGORY OR RATING

CONDITION

MINIMUM

EFFICIENCY

TEST PROCEDURE

Air cooled

(dehumidification mode)

4.0 ISMRE

AHRI 920

Air source heat pumps

(dehumidification mode)

4.0 ISMRE

AHRI 920

Water cooled

(dehumidification mode)

Cooling tower condenser water

4.9 ISMRE

AHRI 920

Chilled water

6.0 ISMRE

Air source heat pump

(heating mode)

2.7 ISCOP

AHRI 920

Water source heat pump

(dehumidification mode)

Ground source, closed loop

4.8 ISMRE

AHRI 920

Ground-water source

5.0 ISMRE

Water source

4.0 ISMRE

Water source heat pump

(heating mode)

Ground source, closed loop

2.0 ISCOP

AHRI 920

Ground-water source

3.2 ISCOP

Water source

3.5 ISCOP

TABLE C403.3.2(12)

MINIMUM EFFICIENCY REQUIREMENTS: ELECTRICALLY OPERATED DX-DOAS UNITS, SINGLE-

PACKAGE AND REMOTE CONDENSER, WITH ENERGY RECOVERY

EQUIPMENT TYPE

SUBCATEGORY OR RATING

CONDITION

MINIMUM

EFFICIENCY

TEST PROCEDURE

Air cooled

(dehumidification mode)

5.2 ISMRE

AHRI 920

Air source heat pumps

(dehumidification mode)

5.2 ISMRE

AHRI 920

Water cooled

(dehumidification mode)

Cooling tower condenser water

5.3 ISMRE

AHRI 920

Chilled water

6.6 ISMRE

Air source heat pump

(heating mode)

3.3 ISCOP

AHRI 920

Water source heat pump

(dehumidification mode)

Ground source, closed loop

5.2 ISMRE

AHRI 920

Ground-water source

5.8 ISMRE

Water source

4.8 ISMRE

Water source heat pump

(heating mode)

Ground source, closed loop

3.8 ISCOP

AHRI 920

Ground-water source

4.0 ISCOP

Water source

4.8 ISCOP

CE-56 2018 Washington State Energy Code

C403.3.2.2 Water-cooled centrifugal chilling package. Equipment not designed for operation at AHRI

Standard 550/590 test conditions of 44°F (7°C) leaving chilled-water temperature and 2.4 gpm/ton

evaporator fluid flow and 85°F (29°C) entering condenser water temperature with 3 gpm/ton (0.054 L/s

kW) condenser water flow shall have maximum full-load kW/ton (FL) and part-load ratings adjusted using

Equations 4-7 and 4-8.

adj

= FL/K

adj

(Equation 4-7)

PLV

adj

= IPLV/K

adj

(Equation 4-8)

Where:

adj

= A × B

FL = Full-load kW/ton values as specified in Table C403.3.2(7)

adj

= Maximum full-load kW/ton rating, adjusted for nonstandard conditions

IPLV = Values as specified in Table C403.3.2(7)

PLV

adj

= Maximum NPLV rating, adjusted for nonstandard conditions.

A = 0.00000014592 × (LIFT)

0.0000346496 × (LIFT)

+ 0.00314196 × (LIFT)

- 0.147199 × LIFT + 3.9302

B = 0.0015 × L

Evap

(°F) + 0.934

LIFT = L

Cond - L

Evap

Cond

= Full-load condenser leaving fluid temperature (°F)

Evap

= Full-load evaporator leaving temperature (°F)

The FL

adj

and PLV

adj

values are only applicable for centrifugal chillers meeting all of the following full-

load design ranges:

1. Minimum evaporator leaving temperature: 36°F.

2. Maximum condenser leaving temperature: 115°F.

3. LIFT is not less than 20°F and not greater than 80°F.

C403.3.2.3 Positive displacement (air- and water-cooled) chilling package. Equipment with a leaving

fluid temperature higher than 32°F (0°C) and water-cooled positive displacement chilling packages with a

condenser leaving fluid temperature below 115°F (46°C) shall meet the requirements of Table C403.3.2(7)

when tested or certified with water at standard rating conditions, in accordance with the referenced test

procedure.

C403.3.2.4 Packaged electric heating and cooling equipment. Packaged electric equipment providing

both heating and cooling with a total cooling capacity greater than 6,000 Btu/h shall be a heat pump.

Exception: Unstaffed equipment shelters or cabinets used solely for personal wireless service facilities.

C403.3.2.5 Humidification. If an air economizer is required on a cooling system for which humidification

equipment is to be provided to maintain minimum indoor humidity levels, then the humidifier shall be of the

adiabatic type (direct evaporative media or fog atomization type).

Exceptions:

1. Health care facilities licensed by the state where Chapter 246-320 or 246-330 WAC requires steam

injection humidifiers in duct work downstream of final filters.

2. Systems with water economizer.

3. 100% outside air systems with no provisions for air recirculation to the central supply fan.

4. Nonadiabatic humidifiers cumulatively serving no more than 10% of a building's air economizer

capacity as measured in cfm. This refers to the system cfm serving rooms with stand-alone or duct

mounted humidifiers.

2018 Washington State Energy Code CE-57

C403.3.3 Hot gas bypass limitation. Cooling systems shall not use hot gas bypass or other evaporator

pressure control systems unless the system is designed with multiple steps of unloading or continuous

capacity modulation. The capacity of the hot gas bypass shall be limited as indicated in Table C403.3.3, as

limited by Section C403.5.1

TABLE C403.3.3

MAXIMUM HOT GAS BYPASS CAPACITY

RATED CAPACITY

MAXIMUM HOT GAS

BYPASS CAPACITY

(% of total capacity)

≤ 240,000 Btu/h

> 240,000 Btu/h

For SI: 1 British thermal unit per hour = 0.2931 W.

C403.3.4 Boiler turndown. Boiler systems with design input of greater than 1,000,000 Btu/h (293 kW) shall

comply with the turndown ratio specified in Table C403.3.4.

The system turndown requirement shall be met through the use of multiple single input boilers, one or more

modulating boilers or a combination of single input and modulating boilers.

TABLE C403.3.4

BOILER TURNDOWN

Boiler System Design Input

(Btu/h)

Minimum

Turndown Ratio

≥1,000,000 and

less than or equal to 5,000,000

3 to 1

> 5,000,000 and

less than or equal to 10,000,000

4 to 1

>10,000,000

5 to 1

C403.3.5 Dedicated outdoor air systems (DOAS). For buildings with occupancies as shown in Table

C403.3.5, outdoor air shall be provided to each occupied space by a dedicated outdoor air system (DOAS)

which delivers 100 percent outdoor air without requiring operation of the heating and cooling system fans for

ventilation air delivery.

Exceptions:

1. Occupied spaces that are not ventilated by a mechanical ventilation system and are only ventilated by

a natural ventilation system in accordance with Section 402 of the International Mechanical Code.

2. High efficiency variable air volume (VAV) systems complying with Section C403.6.10 for occupancy

classifications other than Groups A-1, A-2 and A-3 as specified in Table C403.3.5, and high efficiency

VAV systems complying with Section C403.12 for occupancy classifications Groups A-1, A-2 and A-3

as specified in Table C403.3.5. This exception shall not be used as a substitution for a DOAS per

Section C406.6.

CE-58 2018 Washington State Energy Code

TABLE C403.3.5

OCCUPANCY CLASSIFICATIONS REQUIRING DOAS

Occupancy

Classification

Inclusions

Exempted

A-1

All occupancies not specifically

exempted

Television and radio studios

A-2

Casinos (gaming area)

All other A-2 occupancies

A-3

Lecture halls, community halls,

exhibition halls, gymnasiums,

courtrooms, libraries, places of

religious worship

All other A-3 occupancies

A-4, A-5

All occupancies excluded

All occupancies not specifically

exempted

Food processing establishments including

commercial kitchens, restaurants, cafeterias;

laboratories for testing and research; data

processing facilities and telephone

exchanges; air traffic control towers; animal

hospitals, kennels, pounds; ambulatory care

facilities.

F, H, I, R, S, U

All occupancies excluded

E, M

All occupancies included

a. Occupancy classification from the International Building Code Chapter 3.

C403.3.5.1 Energy recovery ventilation with DOAS. The DOAS shall include energy recovery ventilation.

The energy recovery system shall have a 60 percent minimum sensible recovery effectiveness or have 50

percent enthalpy recovery effectiveness in accordance with Section C403.7.6. For DOAS having a total fan

system motor nameplate hp less than 5 hp, total combined fan power shall not exceed 1 W/cfm of outdoor

air. For DOAS having a total fan system motor hp greater than or equal to 5 hp, refer to fan power limitations

of Section C403.8.1. This fan power restriction applies to each dedicated outdoor air unit in the permitted

project, but does not include the fan power associated with the zonal heating/cooling equipment. The airflow

rate thresholds for energy recovery requirements in Tables C403.7.6(1) and C403.7.6(2) do not apply.

Exceptions:

1. Occupied spaces with all of the following characteristics: complying with Section C403.7.6, served

by equipment less than 5000 cfm, with an average occupant load greater than 25 people per 1000

square feet (93 m

) of floor area (as established in Table 403.3.1.1 of the International Mechanical

Code) that include demand control ventilation configured to reduce outdoor air by at least 50%

below design minimum ventilation rates when the actual occupancy of the space served by the

system is less than the design occupancy.

2. Systems installed for the sole purpose of providing makeup air for systems exhausting toxic,

flammable, paint, or corrosive fumes or dust, dryer exhaust, or commercial kitchen hoods used for

collecting and removing grease vapors and smoke.

C403.3.5.2 Heating/cooling system fan controls. Heating and cooling equipment fans, heating and

cooling circulation pumps, and terminal unit fans shall cycle off and terminal unit primary cooling air shall be

shut off when there is no call for heating or cooling in the zone.

Exception: Fans used for heating and cooling using less than 0.12 watts per cfm may operate when

space temperatures are within the set point dead band (Section C403.4.1.2) to provide destratification and

air mixing in the space.

2018 Washington State Energy Code CE-59

C403.3.5.3 Decoupled DOAS supply air. The DOAS supply air shall be delivered directly to the occupied

space or downstream of the terminal heating and/or cooling coils.

Exceptions:

1. Active chilled beam systems.

2. Sensible only cooling terminal units with pressure independent variable airflow regulating devices

limiting the DOAS supply air to the greater of latent load or minimum ventilation requirements.

3. Terminal heating and/or cooling units that comply with the low fan power allowance requirements in

the exception of Section C403.3.5.2.

C403.3.5.4 Impracticality. Where the code official determines that full compliance with all of the

requirements of Section C403.3.5.1 and C403.3.5.2 would be impractical, it is permissible to provide an

approved alternate means of compliance that achieves a comparable level of energy efficiency. For the

purposes of this section, impractical means that an HVAC system complying with Section C403.3.5 cannot

effectively be utilized due to an unusual use or configuration of the building.

C403.3.6 Ventilation for Group R-2 occupancy. For all Group R-2 dwelling and sleeping units, a balanced

ventilation system with heat recovery system with minimum 60 percent sensible recovery effectiveness shall

provide outdoor air directly to all habitable space. The ventilation system shall allow for the design flow rates

to be tested and verified at each habitable space as part of the commissioning process in accordance with

Section C408.2.2.

C403.4 HVAC system controls. HVAC systems shall be provided with controls in accordance with Sections

C403.4.1 through C403.4.11 and shall be capable of and configured to implement all required control functions

in this code.

C403.4.1 Thermostatic controls. The supply of heating and cooling energy to each zone shall be controlled

by individual thermostatic controls capable of responding to temperature within the zone. Controls in the same

zone or in neighboring zones connected by openings larger than 10 percent of the floor area of either zone

shall not allow for simultaneous heating and cooling. At a minimum, each floor of a building shall be

considered as a separate zone. Controls on systems required to have economizers and serving single zones

shall have multiple cooling stage capability and activate the economizer when appropriate as the first stage of

cooling. See Section C403.5 for further economizer requirements. Where humidification or dehumidification or

both is provided, at least one humidity control device shall be provided for each humidity control system.

Exceptions:

1. Independent perimeter systems that are designed to offset only building envelope heat losses or gains

or both serving one or more perimeter zones also served by an interior system provided:

1.1. The perimeter system includes at least one thermostatic control zone for each building exposure

having exterior walls facing only one orientation (within +/-45 degrees) (0.8 rad) for more than 50

contiguous feet (15,240 mm);

1.2. The perimeter system heating and cooling supply is controlled by a thermostat located within the

zones served by the system; and

1.3. Controls are configured to prevent the perimeter system from operating in a different heating or

cooling mode from the other equipment within the zones or from neighboring zones connected by

openings larger than 10 percent of the floor area of either zone.

2. Any interior zone open to a perimeter zone shall have set points and dead bands coordinated so that

cooling in the interior zone shall not operate while the perimeter zone is in heating until the interior

zone temperature is 5°F (2.8°C) higher than the perimeter zone temperature, unless the interior and

perimeter zones are separated by a partition whose permanent openings are smaller than 10 percent

of the perimeter zone floor area.

3. Dedicated outdoor air units that provide ventilation air, make-up air or replacement air for exhaust

systems are permitted to be controlled based on supply air temperature. The supply air temperature

shall be controlled to a maximum of 65°F (18.3°C) in heating and a minimum of 72°F (22°C) in cooling

unless the supply air temperature is being reset based on the status of cooling or heating in the zones

served or it being reset based on outdoor air temperature.

C403.4.1.1 Heat pump supplementary heat. Unitary air cooled heat pumps shall include microprocessor

controls that minimize supplemental heat usage during start-up, set-up, and defrost conditions. These

controls shall anticipate need for heat and use compression heating as the first stage of heat. Controls shall

indicate when supplemental heating is being used through visual means (e.g., LED indicators). Heat pumps

CE-60 2018 Washington State Energy Code

equipped with supplementary heaters shall be installed with controls that prevent supplemental heater

operation above 40°F (4.4°C).

Exception: Packaged terminal heat pumps (PTHPs) of less than 2 tons (24,000 Btu/hr) cooling capacity

provided with controls that prevent supplementary heater operation above 40°F.

C403.4.1.2 Dead band. Where used to control both heating and cooling, zone thermostatic controls shall be

configured to provide a temperature range or dead band of at least 5°F (2.8°C) within which the supply of

heating and cooling energy to the zone is shut off or reduced to a minimum.

Exceptions:

1. Thermostats requiring manual changeover between heating and cooling modes.

2. Occupancies or applications requiring precision in indoor temperature control as approved by the

code official.

C403.4.1.3 Set point overlap restriction. Where a zone has a separate heating and a separate cooling

thermostatic control located within the zone, a limit switch, mechanical stop or direct digital control system

with software programming shall be configured to prevent the heating set point from exceeding the cooling

set point and to maintain a dead band in accordance with Section C403.4.1.2.

C403.4.1.4 Heated or cooled vestibules. The heating system for heated vestibules and air curtains with

integral heating shall be provided with controls configured to shut off the source of heating when the outdoor

air temperature is greater than 45°F (7°C). Vestibule heating and cooling systems shall be controlled by a

thermostat located in the vestibule configured to limit heating to a temperature not greater than 60°F (16°C)

and cooling to a temperature not less than 85°F (29°C).

Exceptions:

1. Control of heating or cooling provided by transfer air that would otherwise be exhausted.

2. Vestibule heating only systems are permitted to be controlled without an outdoor air temperature

lockout when controlled by a thermostat located in the vestibule configured to limit heating to a

temperature not greater than 45°F (7°C) where required for freeze protection of piping and sprinkler

heads located in the vestibule.

C403.4.1.5 Hot water boiler outdoor temperature setback control. Hot water boilers that supply heat to

the building through one- or two-pipe heating systems shall have an outdoor setback control that lowers the

boiler water temperature based on the outdoor temperature.

C403.4.1.6 Door switches for HVAC system thermostatic control. Doors that open to the outdoors from

a conditioned space must have controls configured to do the following once doors have been open for 5

minutes:

1. Disable the mechanical heating to the zone or reset the space heating temperature set point to 55 °F

or less within 5 minutes of the door open enable signal.

2. Disable the mechanical cooling to the zone or reset the space cooling temperature set point to 85 °F

or more within 5 minutes of the door open enable signal.

Exceptions:

1. Building entrances with vestibules.

2. Alterations to existing buildings.

3. Loading docks.

C403.4.2 Off-hour controls. For all occupancies other than Group R, each zone shall be provided with

thermostatic setback controls that are controlled by either an automatic time clock or programmable control

system.

Exceptions:

1. Zones that will be operated continuously.

2. Zones with a full HVAC load demand not exceeding 6,800 Btu/h (2 kW) and having a manual shutoff

switch located with ready access.

C403.4.2.1 Thermostatic setback. Thermostatic setback controls shall be configured to set back or

temporarily operate the system to maintain zone temperatures down to 55°F (13°C) or up to 85°F (29°C).

C403.4.2.2 Automatic setback and shutdown. Automatic time clock or programmable controls shall be

capable of starting and stopping the system for seven different daily schedules per week and retaining their

programming and time setting during a loss of power for at least 10 hours. Additionally, the controls shall

2018 Washington State Energy Code CE-61

have a manual override that allows temporary operation of the system for up to 2 hours; a manually

operated timer configured to operate the system for up to 2 hours; or an occupancy sensor.

C403.4.2.3 Automatic start and stop. Automatic start and stop controls shall be provided for each HVAC

system. The automatic start controls shall be configured to automatically adjust the daily start time of the

HVAC system in order to bring each space to the desired occupied temperature immediately prior to

scheduled occupancy. The automatic stop controls shall be configured to reduce the HVAC system’s

heating temperature set point and increase the cooling temperature set point by at least 2°F (1.1°C) before

scheduled unoccupied periods based upon the thermal lag and acceptable drift in space temperature that is

within comfort limits. At a minimum, the controls shall be a function of the space temperature, occupied and

unoccupied temperatures, and the amount of time prior to scheduled occupancy.

C403.4.2.4 Exhaust system off-hour controls. For all occupancies other than Group R, exhaust systems

serving spaces within the conditioned envelope shall be controlled by either an automatic time clock,

thermostatic controls or programmable control system to operate on the same schedule as the HVAC

systems providing their make-up air.

Exceptions:

1. Exhaust systems requiring continuous operation.

2. Exhaust systems that are controlled by occupancy sensor control configured with automatic on and

automatic shutoff within 15 minutes after occupants have left the space.

C403.4.2.5 Transfer and destratification fan system off-hour controls. For all occupancies other than

Group R, transfer fan or mixing fan systems serving spaces within the conditioned envelope shall be

controlled by either an automatic time clock, thermostatic controls or programmable control system to

operate on the same schedule as the associated HVAC systems.

Exception: Transfer fan and destratification fan systems that are controlled by occupancy sensor control

configured with manual on and automatic shutoff within 15 minutes after occupants have left the space.

C403.4.3 Hydronic systems controls. The heating of fluids that have been previously mechanically cooled

and the cooling of fluids that have been previously mechanically heated shall be limited in accordance with

Sections C403.4.3.1 through C403.4.3.3. Hydronic heating systems comprised of multiple-packaged boilers

and designed to deliver conditioned water or steam into a common distribution system shall include automatic

controls configured to sequence operation of the boilers. Hydronic heating systems comprised of a single

boiler and greater than 500,000 Btu/h (146,550 W) input design capacity shall include either a multi-staged or

modulating burner.

C403.4.3.1 Three-pipe system. Hydronic systems that use a common return system for both hot water and

chilled water are prohibited.

C403.4.3.2 Two-pipe changeover system. Systems that use a common distribution system to supply both

heated and chilled water shall be designed to allow a dead band between changeover from one mode to the

other of at least 15°F (8.3°C) outside air temperatures; be designed to and provided with controls that will

allow operation in one mode for at least 4 hours before changing over to the other mode; and be provided

with controls that allow heating and cooling supply temperatures at the changeover point to be no more than

30°F (16.7°C) apart.

C403.4.3.3 Hydronic (water loop) heat pump systems. Hydronic heat pump systems shall comply with

Sections C403.4.3.3.1 through C403.4.3.3.3.

C403.4.3.3.1 Temperature dead band. Hydronic heat pumps connected to a common heat pump water

loop with central devices for heat rejection and heat addition shall have controls that are configured to

provide a heat pump water supply temperature dead band of at least 20°F (11.1°C) between initiation of

heat rejection and heat addition by the central devices.

Exception: Where a system loop temperature optimization controller is installed and can determine the

most efficient operating temperature based on real time conditions of demand and capacity, dead bands

of less than 20°F (11°C) shall be permitted.

C403.4.3.3.2 Heat rejection. The following shall apply to hydronic water loop heat pump systems:

1. Where a closed-circuit cooling tower is used directly in the heat pump loop, either an automatic

valve shall be installed to bypass the flow of water around the closed-circuit cooling tower, except

for the minimum flow necessary for freeze protection. Flow controls for freeze protection shall not

CE-62 2018 Washington State Energy Code

allow water through the closed-circuit cooling tower when outdoor temperatures are above the

freezing point of the glycol/water solution, i.e. 32°F (0°C) for 100 percent water applications, and

18°F (-7.8°C) for 20 percent by mass propylene glycol solution.

2. Where an open-circuit cooling tower is used directly in the heat pump loop, an automatic valve shall

be installed to bypass all heat pump water flow around the open-circuit cooling tower.

3. Where an open-circuit cooling tower is used in conjunction with a separate heat exchanger to

isolate the open-circuit cooling tower from the heat pump loop, heat loss shall be controlled by

shutting down the circulation pump on the cooling tower loop.

Exception: Where it can be demonstrated that a heat pump system will be required to reject heat

throughout the year.

C403.4.3.3.3 Isolation valve. Each hydronic heat pump on the hydronic system having a total pump

system power exceeding 10 horsepower (hp) (7.5 kW) shall have a two-way (but not three-way) valve. For

the purposes of this section, pump system power is the sum of the nominal power demand (i.e.,

nameplate horsepower at nominal motor efficiency) of motors of all pumps that are required to operate at

design conditions to supply fluid from the heating or cooling source to all heat transfer devices (e.g., coils,

heat exchanger) and return it to the source. This converts the system into a variable flow system and, as

such, the primary circulation pumps shall comply with the variable flow requirements in Section C403.4.6.

C403.4.4 Part load controls. Hydronic systems greater than or equal to 300,000 Btu/h (88 kW) in design

output capacity supplying heated or chilled water to comfort conditioning systems shall include controls that

are configured to:

1. Automatically reset the supply-water temperatures in response to varying building heating and cooling

demand using coil valve position, zone-return water temperature or outdoor air temperature. The

temperature shall be reset by not less than 25 percent of the design supply-to-return water temperature

difference.

Exception: Hydronic systems serving hydronic heat pumps.

2. Automatically vary fluid flow for hydronic systems with a combined pump motor capacity of 2 hp or

larger with three or more control valves or other devices by reducing the system design flow rate by not

less than 50 percent or the maximum reduction allowed by the equipment manufacturer for proper

operation of equipment by valves that modulate or step open and close, or pumps that modulate or turn

on and off as a function of load.

3. Automatically vary pump flow on heating water systems, chilled-water systems and heat rejection loops

serving water-cooled unitary air conditioners as follows:

3.1. Where pumps operate continuously or operate based on a time schedule, pumps with nominal

output motor power of 2 hp or more shall have a variable speed drive.

3.2. Where pumps have automatic direct digital control configured to operate pumps only when zone

heating or cooling is required, a variable speed drive shall be provided for pumps with motors

having the same or greater nominal output power indicated in Table C403.4.4 based on the climate

zone and system served.

4. Where a variable speed drive is required by Item 3 of this Section, pump motor power input shall be

not more than 30 percent of design wattage at 50 percent of the design water flow. Pump flow shall be

controlled to maintain one control valve nearly wide open or to satisfy the minimum differential

pressure.

Exceptions:

1. Supply-water temperature reset is not required for chilled-water systems supplied by off-site district

chilled water or chilled water from ice storage systems.

2. Variable pump flow is not required on dedicated coil circulation pumps where needed for freeze

protection.

3. Variable pump flow is not required on dedicated equipment circulation pumps where configured in

primary/secondary design to provide the minimum flow requirements of the equipment manufacturer

for proper operation of equipment.

4. Variable speed drives are not required on heating water pumps where more than 50 percent of

annual heat is generated by an electric boiler.

2018 Washington State Energy Code CE-63

TABLE C403.4.4

VARIABLE SPEED DRIVE (VSD) REQUIREMENTS FOR DEMAND-CONTROLLED PUMPS

Climate Zones 4c, 5b

VSD Required for Motors with

Rated Output of at Least

Heating Water Pumps

≥7.5 HP

Chilled water and Heat Rejection Loop Pumps

≥7.5 HP

C403.4.5 Pump isolation. Chilled water plants including more than one chiller shall be capable of and

configured to reduce flow automatically through the chiller plant when a chiller is shut down and automatically

shut off flow to chillers that are shut down. Chillers piped in series for the purpose of increased temperature

differential shall be considered as one chiller.

Boiler systems including more than one boiler shall be capable of and configured to reduce flow

automatically through the boiler system when a boiler is shut down.

C403.4.6 Variable flow controls. Individual pumps required by this code to have variable speed control shall

be controlled in one of the following manners:

1. For systems having a combined pump motor horsepower less than or equal to 20 hp (15 kW) and

without direct digital control of individual coils, pump speed shall be a function of either:

1.1. Required differential pressure; or

1.2. Reset directly based on zone hydronic demand, or other zone load indicators; or

1.3. Reset directly based on pump power and pump differential pressure; or

1.4. Reset directly by an integral controller based on the relationship between variable speed

controller frequency and power.

2. For systems having a combined pump motor horsepower that exceeds 20 hp (15 kW) or smaller

systems with direct digital control, pump speed shall be a function of either:

2.1. The static pressure set point as reset based on the valve requiring the most pressure; or

2.2. Directly controlled based on zone hydronic demand; or

2.3. Reset directly by an integral controller based on the relationship between variable speed

controller frequency and power.

C403.4.7 Combustion heating equipment controls. Combustion heating equipment with a capacity over

225,000 Btu/h shall have modulating or staged combustion control.

Exceptions:

1. Boilers.

2. Radiant heaters.

C403.4.7.1 Combustion decorative vented appliance, combustion fireplace and fire pit controls.

Combustion decorative vented appliances, combustion fireplaces and fire pits shall be equipped with local

controls to limit operation to a maximum duration of one hour without override hold capability or shall be

controlled by occupancy sensor control configured with manual on and automatic shutoff within 15 minutes

after occupants have left the space.

C403.4.8 Group R-1 hotel/motel guestrooms. See Section C403.7.4.

C403.4.9 Group R-2 and R-3 dwelling units. The primary space conditioning system within each dwelling

unit shall be provided with at least one programmable thermostat for the regulation of space temperature. The

thermostat shall allow for, at a minimum, a 5-2 programmable schedule (weekdays/weekends) and be capable

of providing at least two programmable setback periods per day.

Each additional system provided within the dwelling unit shall be provided with at least one adjustable

thermostat for the regulation of temperature.

Exceptions:

1. Systems controlled by an occupant sensor that is configured to shut the system off when no

occupant is sensed for a period of up to 30 minutes.

2. Systems controlled solely by a manually operated timer configured to operate the system for no

more than two hours.

CE-64 2018 Washington State Energy Code

3. Ductless heat pumps.

Each thermostat shall be capable of being set by adjustment or selection of sensors and configured as

follows:

1. When used to control heating only: 55°F to 75°F.

2. When used to control cooling only: 70°F to 85°F.

3. All other: 55°F to 85°F with an adjustable dead band configured to at least 5°F in accordance with

Section C403.4.1.2.

C403.4.10 Group R-2 sleeping units. The primary space conditioning system within each sleeping unit shall

be provided with at least one programmable thermostat for the regulation of space temperature. The

thermostat shall allow for, at a minimum, a 5-2 programmable schedule (weekdays/weekends) and be capable

of providing at least two programmable setback periods per day.

Each additional system provided within the sleeping unit shall be provided with at least one adjustable

thermostat for the regulation of temperature.

Exceptions:

1. Systems controlled by an occupant sensor that is configured to shut the system off when no occupant

is sensed for a period of up to 30 minutes.

2. Systems controlled solely by a manually operated timer configured to operate the system for no more

than two hours.

3. Zones with a full HVAC load demand not exceeding 3,400 Btu/h (1 kW) and having a manual shutoff

switch located with ready access.

4. Ductless heat pumps.

Each thermostat shall be capable of being set by adjustment or selection of sensors and configured as

follows:

1. When used to control heating only: 55°F to 75°F;

2. When used to control cooling only: 70°F to 85°F;

3. All other: 55°F to 85°F with an adjustable dead band configured to at least 5°F in accordance with

Section C403.4.1.2.

C403.4.11 Direct digital control systems. Direct digital control (DDC) shall be required as specified in

Sections C403.4.11.1 through C403.4.11.3.

C403.4.11.1 DDC applications. DDC shall be provided in the applications and qualifications listed in Table

C403.4.11.1.

TABLE C403.4.11.1

DDC APPLICATIONS AND QUALIFICATIONS

Building Status

Application

Qualifications

New Building

Air-handling system and all zones served by

the system

All air-handling systems in buildings with building cooling

capacity greater than 780,000 Btu/h

Air-handling system and all zones served by

the system

Individual systems supplying more than three zones and

with fan system bhp of 10 hp and larger

Chilled-water plant and all coils and terminal

units served by the system

Individual plants supplying more than three zones and

with design cooling capacity of 300,000 Btu/h and larger

Hot-water plant and all coils and terminal

units served by the system

Individual plants supplying more than three zones and

with design heating capacity of 300,000 Btu/h and larger

Alteration or addition

Zone terminal units such as VAV box

Where existing zones served by the same air-handling,

chilled-water, or hot-water system have DDC

Air-handling system or fan coil

Where existing air-handling system(s) and fan coil(s)

served by the same chilled- or hot-water plant have DDC

New air-handling system and all new zones

served by the system

Individual systems with fan system bhp 10 hp and larger

and supplying more than three zones and more than 75%

of zones are new

New or upgraded chilled-water plant

Where all chillers are new and plant design cooling

capacity is 300,000 Btu/h and larger

New or upgraded hot-water plant

Where all boilers are new and plant design heating

capacity is 300,000 Btu/h and larger

2018 Washington State Energy Code CE-65

C403.4.11.2 DDC controls. Where DDC is required by Section C403.4.11.1, the DDC system shall be

capable of all of the following, as required to provide the system and zone control logic required in Sections

C403.2, C403.4.3, C403.5, and C403.6.8:

1. Monitoring zone and system demand for fan pressure, pump pressure, heating and cooling.

2. Transferring zone and system demand information from zones to air distribution system controllers

and from air distribution systems to heating and cooling plant controllers.

C403.4.11.3 DDC display. Where DDC is required by Section C403.4.11.1 for new buildings, the DDC

system shall be capable of trending and graphically displaying input and output points.

C403.5 Economizers. Air economizers shall be provided on all new cooling systems including those serving

computer server rooms, electronic equipment, radio equipment, and telephone switchgear. Economizers shall

comply with Sections C403.5.1 through C403.5.5.

Exception: Economizers are not required for the systems listed below:

1. Cooling systems not installed outdoors nor in a mechanical room adjacent to outdoors and installed in

conjunction with DOAS complying with Section C403.3.5 and serving only spaces with year-round

cooling loads from lights and equipment of less than 5 watts per square foot.

2. Unitary or packaged systems serving one zone with dehumidification that affect other systems so as to

increase the overall building energy consumption. New humidification equipment shall comply with

Section C403.3.2.5.

3. Unitary or packaged systems serving one zone where the cooling efficiency meets or exceeds the

efficiency requirements in Table C403.5.

4. Equipment serving chilled beams and chilled ceiling space cooling systems only which are provided with

a water economizer meeting the requirements of Section C403.5.4.

5. For Group R occupancies, cooling units installed outdoors or in a mechanical room adjacent to outdoors

with a total cooling capacity less than 20,000 Btu/h and other cooling units with a total cooling capacity

less than 54,000 Btu/h provided that these are high-efficiency cooling equipment with IEER, CEER,

SEER, and EER values more than 15 percent higher than minimum efficiencies listed in Tables

C403.3.2(1) through (3), in the appropriate size category, using the same test procedures. Equipment

shall be listed in the appropriate certification program to qualify for this exception. For split systems,

compliance is based on the cooling capacity of individual fan coil units.

6. Equipment used to cool Controlled Plant Growth Environments provided these are high-efficiency

cooling equipment with SEER, EER and IEER values a minimum of 20 percent greater than the values

listed in Tables C403.3.2(1), (3) and (7).

7. Equipment serving a space with year-round cooling loads from lights and equipment of 5 watts per

square foot or greater complying with the following criteria:

7.1. Equipment serving the space utilizes chilled water as the cooling source; and

7.2. The chilled water plant includes a condenser heat recovery system that meets the requirements of

Section C403.9.5 or the building and water-cooled system meets the following requirements:

7.2.1. A minimum of 90 percent (capacity-weighted) of the building space heat is provided by

hydronic heating water.

7.2.2. Chilled water plant includes a heat recovery chiller or water-to-water heat pump capable of

rejecting heat from the chilled water system to the hydronic heating equipment capacity.

7.2.3. Heat recovery chillers shall have a minimum COP of 7.0 when providing heating and cooling water

simultaneously.

8. Water-cooled equipment served by systems meeting the requirements of Section C403.9.2.4,

Condenser heat recovery.

9. Dedicated outdoor air systems that include energy recovery as required by Section C403.7.6 but that do

not include mechanical cooling.

10. Dedicated outdoor air systems not required by Section C403.7.6 to include energy recovery that

modulate the supply airflow to provide only the minimum outdoor air required by Section C403.2.2.1 for

ventilation, exhaust air make-up, or other process air delivery.

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11. Equipment used to cool any dedicated server room, electronic equipment room or telecom switch room

provided the system complies with Option a, b or c in the table below. The total cooling capacity of all

fan systems without economizers shall not exceed 240,000 Btu/h per building or 10 percent of its air

economizer capacity, whichever is greater. This exception shall not be used for Total Building

Performance.

Equipment Type

Higher Equipment

Efficiency

Part-Load Control

Economizer

Option a

Tables C403.3.2(1) and

C403.3.2(2)

+15%

Required over

85,000 Btu/h

None Required

Option b

Tables C403.3.2(1) and

C403.3.2(2)

+5%

Required over

85,000 Btu/h

Water-side

Economizer

Option c

ASHRAE Standard 127

+0%

Required over

85,000 Btu/h

Water-side

Economizer

Notes for Exception 11:

a. For a system where all of the cooling equipment is subject to the AHRI standards listed in Tables C403.3.2(1) and

C403.3.2(2), the system shall comply with all of the following (note that if the system contains any cooling

equipment that exceeds the capacity limits in Table C403.3.2(1) or C403.3.2(2), or if the system contains any

cooling equipment that is not included in Table C403.3.2(1) or C403.3.2(2), then the system is not allowed to use

this option).

b. The cooling equipment shall have an EER value and an IPLV value that is a minimum of 15 percent greater than

the value listed in Tables C403.3.2(1) and C403.3.2(2).

c. For units with a total cooling capacity over 85,000 Btu/h, the system shall utilize part-load capacity control schemes

that are able to modulate to a part-load capacity of 50 percent of the load or less that results in the compressor

operating at the same or

higher EER at part loads than at full load (e.g., minimum of two-stages of compressor unloading such as cylinder

unloading, two-stage scrolls, dual tandem scrolls, but hot gas bypass is not credited as a compressor unloading

system).

d. The cooling equipment shall have an EER value and an IPLV value that is a minimum of 5 percent greater than the

value listed in Tables C403.3.2(1) and C403.3.2(2).

e. The system shall include a water economizer in lieu of air economizer. Water economizers shall meet the

requirements of Sections C403.5.1 and C403.5.2 and be capable of providing the total concurrent cooling load

served by the connected terminal equipment lacking airside economizer, at outside air temperatures of 50°F dry-

bulb/45°F wet-bulb and below. For this calculation, all factors including solar and internal load shall be the same as

those used for peak load calculations, except for the outside temperatures. The equipment shall be served by a

dedicated condenser water system unless a non-dedicated condenser water system exists that can provide

appropriate water temperatures during hours when water-side economizer cooling is available.

f. For a system where all cooling equipment is subject to ASHRAE Standard 127.

g. The cooling equipment subject to ASHRAE Standard 127 shall have an EER value and an IPLV value that is equal

or greater than the value listed in Tables C403.3.2(1) and C403.3.2(2) when determined in accordance with the

rating conditions in ASHRAE Standard 127 (i.e., not the rating conditions in AHRI Standard 210/240 or 340/360).

This information shall be provided by an independent third party.

TABLE C403.5

EQUIPMENT EFFICIENCY PERFORMANCE EXCEPTION FOR ECONOMIZERS

Climate

Zone

Efficiency

Improvement

64%

59%

a. If a unit is rated with an IPLV, IEER or SEER then to eliminate the required air or water economizer, the minimum

cooling efficiency of the HVAC unit must be increased by the percentage shown. If the HVAC unit is only rated with

a full load metric like EER or COP cooling, then these must be increased by the percentage shown.

2018 Washington State Energy Code CE-67

C403.5.1 Integrated economizer control. Economizer systems shall be integrated with the mechanical

cooling system and be configured to provide partial cooling even where additional mechanical cooling is

required to provide the remainder of the cooling load. Controls shall not be capable of creating a false load in

the mechanical cooling system by limiting or disabling the economizer or any other means, such as hot gas

bypass, except at the lowest stage of mechanical cooling.

Units that include an air economizer shall comply with the following:

1. Unit controls shall have the mechanical cooling capacity control interlocked with the air economizer

controls such that the outdoor air damper is at the 100 percent open position when mechanical

cooling is on and the outdoor air damper does not begin to close to prevent coil freezing due to

minimum compressor run time until the leaving air temperature is less than 45°F (7°C).

2. Direct expansion (DX) units with cooling capacity 65,000 Btu/H (19 kW) or greater of rated capacity

shall comply with the following:

2.1. DX units that control the capacity of the mechanical cooling directly based on occupied space

temperature shall have not fewer than two stages of mechanical cooling capacity.

2.2. Other DX units, including those that control space temperature by modulating the airflow to the

space, shall be in accordance with Table C403.5.1.

TABLE C403.5.1

DX COOLING STAGE REQUIREMENTS FOR MODULATING AIRFLOW UNITS

Rating Capacity

Minimum Number of Mechanical

Cooling Stages

Minimum Compressor

Displacement

≥ 65,000 Btu/h and < 240,000

Btu/h

3 stages

≤ 35% of full load

≥ 240,000 Btu/h

4 stages

≤ 25% of full load

For SI: 1 Btu/h = 0.2931 W

a. For mechanical cooling stage control that does not use variable compressor displacement, the percent

displacement shall be equivalent to the mechanical cooling capacity reduction evaluated at the full load rating

conditions for the compressor.

C403.5.2 Economizer heating system impact. HVAC system design and economizer controls shall be such

that economizer operation does not increase building heating energy use during normal operation.

Exception: Economizers on VAV systems that cause zone level heating to increase due to a reduction in

supply air temperature.

C403.5.3. Air economizers. Air economizers shall comply with Sections C403.5.3.1 through C403.5.3.5.

C403.5.3.1 Design capacity. Air economizer systems shall be configured to modulate outdoor air and

return air dampers to provide up to 100 percent of the design supply air quantity as outdoor air for cooling.

C403.5.3.2 Control signal. Economizer controls and dampers shall be configured to sequence the dampers

with mechanical cooling equipment and shall not be controlled by only mixed air temperature. Air

economizers on systems with cooling capacity greater than 65,000 Btu/h shall be configured to provide

partial cooling even when additional mechanical cooling is required to meet the remainder of the cooling

load.

Exception: The use of mixed air temperature limit control shall be permitted for systems that are both

controlled from space temperature (such as single zone systems) and having cooling capacity less than

65,000 Btu/h.

C403.5.3.3 High-limit shutoff. Air economizers shall be configured to automatically reduce outdoor air

intake to the design minimum outdoor air quantity when outdoor air intake will no longer reduce cooling

energy usage. High-limit shutoff control types shall be chosen from Table C403.5.3.3. High-limit shutoff

control settings for these control types shall be those specified in Table C403.5.3.3.

CE-68 2018 Washington State Energy Code

TABLE C403.5.3.3

HIGH-LIMIT SHUTOFF CONTROL SETTING FOR AIR ECONOMIZERS

DEVICE TYPE

REQUIRED HIGH LIMIT

(Economizer Off When):

REQUIRED HIGH LIMIT FOR CYCLING FANS

(Economizer Off When):

EQUATION

DESCRIPTION

EQUATION

DESCRIPTION

Fixed dry bulb

TOA > 75°F

Outdoor air temperature

exceeds 75°F

TOA > 70°F

Outdoor air temperature

exceeds 70°F

Differential dry bulb

> T

Outdoor air temperature

exceeds return air

temperature

> (T

- 5)

Outdoor air temperature

exceeds return air

temperature - 5°F

Fixed enthalpy with fixed

dry-bulb temperatures

> 28

Btu/lb

> 75°F

Outdoor air enthalpy

exceeds 28 Btu/lb of dry

air

or outdoor

temperature exceeds

75°F

> 26 Btu/lb

> 70°F

Outdoor air enthalpy

exceeds 26 Btu/lb of dry

air

or outdoor temperature

exceeds 70°F

Differential enthalpy with

fixed dry-bulb

temperatures

> h

> 75°F

Outdoor air enthalpy

exceeds return air

enthalpy oroutdoor

temperature exceeds

75°F

> (h

– 2)

> 70°F

Outdoor air enthalpy

exceeds return air

enthalpy

or outdoor temperature

exceeds 70°F

For SI: °C = (°F - 32) × 5/9, 1 Btu/lb = 2.33 kJ/kg.

a. At altitudes substantially different than sea level, the Fixed Enthalpy limit shall be set to the enthalpy value at 75°F and

50-percent relative humidity. As an example, at approximately 6,000 feet elevation the fixed enthalpy limit is

approximately 30.7 Btu/lb.

b. Devices with selectable set point shall be capable of being set to within 2°F and 2 Btu/lb of the set point listed.

c. Where fans cycle on only to provide heating and cooling, limits are adjusted lower to compensate for fan energy use in

economizer mode.

d. For cycling fans, at altitudes substantially different than sea level, the fixed enthalpy limit shall be set to the enthalpy

value at 70°F and 50% relative humidity.

C403.5.3.4 Relief of excess outdoor air. Systems shall be capable of relieving excess outdoor air during

air economizer operation to prevent over-pressurizing the building. The relief air outlet shall be located to

avoid recirculation into the building.

C403.5.3.5 Economizer dampers. Return, exhaust/relief and outdoor air dampers used in economizers

shall comply with Section C403.7.8.

C403.5.4 Water-side economizers. Water-side economizers shall comply with Sections C403.5.4.1 and

C403.5.4.2.

C403.5.4.1 Design capacity. Water economizer systems shall be configured to cool supply air by indirect

evaporation and providing up to 100 percent of the expected system cooling load at outdoor air

temperatures of not greater than 50°F dry-bulb (10°C dry-bulb)/45°F wet-bulb (7.2°C wet-bulb.

Exception: Systems where dehumidification requirements cannot be met using outdoor air temperatures

of 50°F dry-bulb (10°C dry-bulb)/45°F wet-bulb (7.2°C wet-bulb) and where 100 percent of the expected

system cooling load at 45°F dry-bulb (7.2°C dry-bulb)/40°F wet-bulb (4.5°C wet-bulb) is met with

evaporative water economizers.

C403.5.4.2 Maximum pressure drop. Precooling coils and water-to-water heat exchangers used as part of

a water economizer system shall either have a water-side pressure drop of less than 15 feet (4572 mm) of

water or a secondary loop shall be created so that the coil or heat exchanger pressure drop is not seen by

the circulating pumps when the system is in the normal cooling (noneconomizer) mode.

C403.5.5 Economizer fault detection and diagnostics (FDD). Air-cooled unitary direct-expansion units with

a cooling capacity of 54,000 Btu/h or greater listed in Tables C403.3.2(1) through C403.3.2(3) that are

equipped with an economizer in accordance with Section C403.5 shall include a fault detection and

diagnostics (FDD) system complying with the following:

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◄

1. The following temperature sensors shall be permanently installed to monitor system operation:

1.1. Outside air.

1.2. Supply air.

1.3. Return air.

2. Temperature sensors shall have an accuracy of ±2°F (1.1°C) over the range of 40°F to 80°F (4°C to

26.7°C).

3. Refrigerant pressure sensors, where used, shall have an accuracy of ±3 percent of full scale.

4. The unit controller shall be configured to provide system status by indicating the following:

4.1. Free cooling available.

4.2. Economizer enabled.

4.3. Compressor enabled.

4.4. Heating enabled.

4.5. Mixed air low limit cycle active.

4.6. The current value of each sensor.

5. The unit controller shall be capable of manually initiating each operating mode so that the operation of

compressors, economizers, fans and the heating system can be independently tested and verified.

6. The unit shall be configured to report faults to a fault management application available for access by

day-to-day operating or service personnel or annunciated locally on zone thermostats.

7. The FDD system shall be configured to detect the following faults:

7.1. Air temperature sensor failure/fault.

7.2. Not economizing when the unit should be economizing.

7.3. Economizing when the unit should not be economizing.

7.4. Damper not modulating.

7.5. Excess outdoor air.

C403.6 Requirements for mechanical systems serving multiple zones. Sections C403.6.1 through

C403.6.10 shall apply to mechanical systems serving multiple zones.

C403.6.1 Variable air volume (VAV) and multiple zone systems. Supply air systems serving multiple zones

shall be VAV systems that have zone controls configured to reduce the volume of air that is reheated,

recooled or mixed in each zone to one of the following:

1. Twenty percent of the zone design peak supply for systems with DDC and thirty percent of the

maximum supply air for other systems.

2. Systems with DDC where items 2.1 through 2.3 apply.

2.1 The airflow rate in the dead band between heating and cooling does not exceed 20 percent of the

zone design peak supply rate or higher allowed rates under items 3, 4 or 5 of this section.

2.2 The first stage of heating modulates the zone supply air temperature set point up to a maximum set

point while the airflow is maintained at the dead band flow rate.

2.3 The second stage of heating modulates the airflow rate from the dead band flow rate up to the

heating maximum flow rate that is less than 50 percent of the zone design peak supply rate.

3. The outdoor airflow rate required to meet the minimum ventilation requirements of Chapter 4 of the

International Mechanical Code.

4. Any higher rate that can be demonstrated to reduce overall system annual energy use by offsetting

reheat/recool energy losses through a reduction in outdoor air intake for the system as approved by the

code official.

5. The airflow rate required to comply with applicable codes or accreditation standards such as pressure

relationships or minimum air change rates.

Exception: The following individual zones or entire air distribution systems are exempted from the

requirement for VAV control:

1. Zones or supply air systems where not less than 75 percent of the energy for reheating or for

providing warm air in mixing systems is provided from a site-recovered source, including

condenser heat.

2. Systems that prevent reheating, recooling, mixing or simultaneous supply of air that has been

previously cooled, either mechanically or through the use of economizer systems, and air that has

been previously mechanically heated.

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3. .Ventilation systems complying with Section C403.3.5, DOAS, with ventilation rates complying

with Section C403.2.2.

C403.6.2 Single duct variable air volume (VAV) systems, terminal devices. Single duct VAV systems

shall use terminal devices capable of and configured to reduce the supply of primary supply air before

reheating or recooling takes place.

C403.6.3 Dual duct and mixing VAV systems, terminal devices. Systems that have one warm air duct and

one cool air duct shall use terminal devices which are capable of and configured to reduce the flow from one

duct to a minimum before mixing of air from the other duct takes place.

C403.6.4 Supply-air temperature reset controls. Multiple zone HVAC systems shall include controls that

automatically reset the supply-air temperature in response to representative building loads, or to outdoor air

temperature. The controls shall be configured to reset the supply air temperature at least 25 percent of the

difference between the design supply-air temperature and the design room air temperature.

Exceptions:

1. Systems that prevent reheating, recooling or mixing of heated and cooled supply air.

2. Seventy-five percent (75%) of the energy for reheating is from a site-recovered source.

3. Zones with peak supply air quantities of 300 cfm (142 L/s) or less.

C403.6.5 Multiple-zone VAV system ventilation optimization control. Multiple-zone VAV systems with

direct digital control of individual zone boxes reporting to a central control panel shall have automatic controls

configured to reduce outdoor air intake flow below design rates in response to changes in system ventilation

efficiency (E

) as defined by the International Mechanical Code.

Exceptions:

1. VAV systems with zonal transfer fans that recirculate air from other zones without directly mixing it

with outdoor air, dual-duct dual-fan VAV systems, and VAV systems with fan-powered terminal units.

2. Systems where total design exhaust airflow is more than 70 percent of total design outdoor air intake

flow requirements.

C403.6.6 Parallel-flow fan-powered VAV air terminal control. Parallel-flow fan-powered VAV air terminals

shall have automatic controls configured to:

1. Turn off the terminal fan except when space heating is required or where required for ventilation.

2. Turn on the terminal fan as the first stage of heating before the heating coil is activated.

3. During heating for warmup or setback temperature control, either:

3.1. Operate the terminal fan and heating coil without primary air.

3.2. Reverse the terminal damper logic and provide heating from the central air handler by primary air.

C403.6.7 Hydronic and multiple-zone HVAC system controls and equipment. Hydronic and multiple-zone

HVAC system controls and equipment shall comply with this section.

For buildings with a total equipment cooling capacity of 300 tons and above, the equipment shall comply

with one of the following:

1. No one unit shall have a cooling capacity of more than 2/3 of the total installed cooling equipment

capacity.

2. The equipment shall have a variable speed drive.

3. The equipment shall have multiple compressors.

C403.6.8 Set points for direct digital control. For systems with direct digital control of individual zones

reporting to the central control panel, the static pressure set point shall be reset based on the zone requiring

the most pressure. In such cases, the set point is reset lower until one zone damper is nearly wide open. The

direct digital controls shall be capable of monitoring zone damper positions or shall have an alternative

method of indicating the need for static pressure that is configured to provide all of the following:

1. Automatically detecting any zone that excessively drives the reset logic.

2. Generating an alarm to the system operational location.

3. Allowing an operator to readily remove one or more zones from the reset algorithm.

C403.6.9 Static pressure sensor location. Static pressure sensors used to control VAV fans shall be located

such that the controller set point is no greater than 1.2 inches w.c. (299 Pa). Where this results in one or more

2018 Washington State Energy Code CE-71

sensors being located downstream of major duct splits, not less than one sensor shall be located on each

major branch to ensure that static pressure can be maintained in each branch.

Exception: Systems complying with Section C403.6.8.

C403.6.10 High efficiency variable air volume (VAV) systems. For HVAC systems subject to the

requirements of Section C403.3.5 but utilizing Exception 2 of that section, a high efficiency multiple-zone VAV

system may be provided without a separate parallel DOAS when the system is designed, installed, and

configured to comply with all of the following criteria (this exception shall not be used as a substitution for a

DOAS per Section C406.6:

1. Each VAV system must serve a minimum of 3,000 square feet (278.7 m

) and have a minimum of five

VAV zones.

2. The VAV systems are provided with airside economizer per Section C403.5 without exceptions.

3. A direct-digital control (DDC) system is provided to control the VAV air handling units and associated

terminal units per Section C403.4.11 regardless of sizing thresholds of Table C403.4.11.1.

4. Multiple-zone VAV systems with a minimum outdoor air requirement of 2,500 cfm (1180 L/s) or greater

shall be equipped with a device capable of measuring outdoor airflow intake under all load conditions.

The system shall be capable of increasing or reducing the outdoor airflow intake based on feedback

from the VAV terminal units as required by Section C403.6.5, without exceptions, and Section C403.7.1,

Demand controlled ventilation.

5. Multiple-zone VAV systems with a minimum outdoor air requirement of 2,500 cfm (1180 L/s) or greater

shall be equipped with a device capable of measuring supply airflow to the VAV terminal units under all

load conditions.

6. In addition to meeting the zone isolation requirements of C403.2.1 a single VAV air handling unit shall

not serve more than 50,000 square feet (4645 m

) unless a single floor is greater than 50,000 square

feet (4645 m

) in which case the air handler is permitted to serve the entire floor.

7. The primary maximum cooling air for the VAV terminal units serving interior cooling load driven zones

shall be sized for a supply air temperature that is a minimum of 5°F greater than the supply air

temperature for the exterior zones in cooling.

8. Air terminal units with a minimum primary airflow set point of 50 percent or greater of the maximum

primary airflow set point shall be sized with an inlet velocity of no greater than 900 feet per minute.

Allowable fan motor horsepower shall not exceed 90 percent of the allowable HVAC fan system bhp

(Option 2) as defined by Section C403.8.1.1.

9. All fan powered VAV terminal units (series or parallel) shall be provided with electronically commutated

motors. The DDC system shall be configured to vary the speed of the motor as a function of the heating

and cooling load in the space. Minimum speed shall not be greater than 66 percent of design airflow

required for the greater of heating or cooling operation. Minimum speed shall be used during periods of

low heating and cooling operation and ventilation-only operation.

Exception: For series fan powered terminal units where the volume of primary air required to deliver

the ventilation requirements at minimum speed exceeds the air that would be delivered at the speed

defined above, the minimum speed set point shall be configured to exceed the value required to

provide the required ventilation air.

10. Fan-powered VAV terminal units shall only be permitted at perimeter zones with an envelope heating

load requirement. All other VAV terminal units shall be single duct terminal units.

Exception: Fan powered VAV terminal units are allowed at interior spaces with an occupant load

greater than or equal to 25 people per 1000 square feet of floor area (as established in Table

403.3.1.1 of the International Mechanical Code) with demand control ventilation in accordance with

Section C403.7.1.

11. When in occupied heating or in occupied dead band between heating and cooling all fan powered VAV

terminal units shall be configured to reset the primary air supply set point, based on the VAV air

handling unit outdoor air vent fraction, to the minimum ventilation airflow required per International

Mechanical Code.

12. Spaces that are larger than 150 square feet (14 m

) and with an occupant load greater than or equal to

25 people per 1000 square feet (93 m

) of floor area (as established in Table 403.3.1.1 of the

International Mechanical Code) shall be provided with all of the following features:

12.1. A dedicated VAV terminal unit capable of controlling the space temperature and minimum

ventilation shall be provided.

CE-72 2018 Washington State Energy Code

12.2. Demand control ventilation (DCV) shall be provided that utilizes a carbon dioxide sensor to reset

the ventilation set point of the VAV terminal unit from the design minimum to design maximum

ventilation rate as required by Chapter 4 of the International Mechanical Code.

12.3. Occupancy sensors shall be provided that are configured to reduce the minimum ventilation rate

to zero and setback room temperature set points by a minimum of 5°F, for both cooling and

heating, when the space is unoccupied.

13. Dedicated data centers, computer rooms, electronic equipment rooms, telecom rooms, or other similar

spaces with cooling loads greater than 5 watts/ft

shall be provided with separate, cooling systems to

allow the VAV air handlers to turn off during unoccupied hours in the office space and to allow the

supply air temperature reset to occur.

Exception: The VAV air handling unit and VAV terminal units may be used for secondary backup

cooling when there is a failure of the primary HVAC system.

Additionally, computer rooms, electronic equipment rooms, telecom rooms, or other similar spaces

shall be provided with airside economizer in accordance with Section C403.5 without using the

exceptions to Section C403.5.

Exception: Heat recovery per exception 9 of Section C403.5 may be in lieu of airside economizer for

the separate, independent HVAC system.

14. HVAC system central heating or cooling plant will include a minimum of one of the following options:

14.1. VAV terminal units with hydronic heating coils connected to systems with hot water generation

equipment limited to the following types of equipment: gas-fired hydronic boilers with a thermal

efficiency, E

, of not less than 92 percent, air-to-water heat pumps or heat recovery chillers.

Hydronic heating coils shall be sized for a maximum entering hot water temperature of 120°F

(48.9°C) for peak anticipated heating load conditions.

14.2. Chilled water VAV air handing units connected to systems with chilled water generation

equipment with IPLV values more than 25 percent higher than the minimum part load efficiencies

listed in Table C403.3.2(7), in the appropriate size category, using the same test procedures.

Equipment shall be listed in the appropriate certification program to qualify. The smallest chiller or

compressor in the central plant shall not exceed 20 percent of the total central plant cooling

capacity or the chilled water system shall include thermal storage sized for a minimum of 20

percent of the total central cooling plant capacity.

15. The DDC system shall include a fault detection and diagnostics (FDD) system complying with the

following:

15.1. The following temperature sensors shall be permanently installed to monitor system operation:

15.1.1. Outside air.

15.1.2. Supply air.

15.1.3. Return air.

15.2. Temperature sensors shall have an accuracy of ±2°F (1.1°C) over the range of 40°F to 80°F (4°C

to 26.7°C).

15.3. The VAV air handling unit controller shall be configured to provide system status by indicating the

following:

15.3.1. Free cooling available.

15.3.2. Economizer enabled.

15.3.3. Compressor enabled.

15.3.4. Heating enabled.

15.3.5. Mixed air low limit cycle active.

15.3.6. The current value of each sensor.

15.4. The VAV air handling unit controller shall be capable of manually initiating each operating mode

so that the operation of compressors, economizers, fans and the heating system can be

independently tested and verified.

15.5. The VAV air handling unit shall be configured to report faults to a fault management application

able to be accessed by day-to-day operating or service personnel or annunciated locally on zone

thermostats.

15.6. The VAV terminal unit shall be configured to report if the VAV inlet valve has failed by

performing the following diagnostic check at a maximum interval of once a month:

15.6.1. Command VAV terminal unit primary air inlet valve closed and verify that primary airflow

goes to zero.

2018 Washington State Energy Code CE-73

15.6.2. Command VAV thermal unit primary air inlet valve to design airflow and verify that unit

is controlling to with 10% of design airflow.

15.7. The VAV terminal unit shall be configured to report and trend when the zone is driving the

following VAV air handling unit reset sequences. The building operator shall have the capability to

exclude zones used in the reset sequences from the DDC control system graphical user interface:

15.7.1. Supply air temperature set point reset to lowest supply air temperature set point for

cooling operation.

15.7.2. Supply air duct static pressure set point reset for the highest duct static pressure set

point allowable.

15.8. The FDD system shall be configured to detect the following faults:

15.8.1. Air temperature sensor failure/fault.

15.8.2. Not economizing when the unit should be economizing.

15.8.3. Economizing when the unit should not be economizing.

15.8.4. Outdoor air or return air damper not modulating.

15.8.5. Excess outdoor air.

15.8.6. VAV terminal unit primary air valve failure.

C403.7 Ventilation and exhaust systems. In addition to other requirements of Section C403 applicable to the

provisions of ventilation air or the exhaust of air, ventilation and exhaust systems shall be in accordance with

Sections C403.7.1 through C403.7.8.

C403.7.1 Demand control ventilation. Demand control ventilation (DCV) shall be provided for spaces larger

than 500 square feet (46 m

) and with an occupant load greater than or equal to 25 people per 1000 square

feet (93 m

) of floor area (as established in Table 403.3.1.1 of the International Mechanical Code) and served

by systems with one or more of the following:

1. An air-side economizer.

2. Automatic modulating control of the outdoor air damper.

3. A design outdoor airflow greater than 3,000 cfm (1416 L/s).

Exception: Demand control ventilation is not required for systems and spaces as follows:

1. Systems with energy recovery complying with Section C403.7.6.1 or Section C403.3.5.1. This

exception is not available for space types located within the “inclusions” column of Groups A-1 and

A-3 occupancy classifications of Table C403.3.5.

2. Multiple-zone systems without direct digital control of individual zones communicating with a central

control panel.

3. System with a design outdoor airflow less than 750 cfm (354 L/s).

4. Spaces where the supply airflow rate minus any makeup or outgoing transfer air requirement is less

than 1,200 cfm (566 L/s).

5. Ventilation provided for process loads only.

6. Spaces with one of the following occupancy categories (as defined by the International Mechanical

Code): Correctional cells, daycare sickrooms, science labs, barbers, beauty and nail salons, and

bowling alley seating.

C403.7.2 Occupancy sensors. Classrooms, gyms, auditoriums, conference rooms, and other spaces with an

occupant load greater than or equal to 25 people per 1000 square feet (93 m

) of floor area (as established in

Table 403.3.1.1 of the International Mechanical Code) that are larger than 500 square feet (46 m

) of floor

area shall have occupancy sensor control that will either close outside air dampers, close ventilation supply

dampers or turn off ventilation equipment when the space is unoccupied except where equipped with another

means to automatically reduce outside air intake below design rates when spaces are partially occupied.

Exceptions:

1. Spaces with one of the following occupancy categories (as defined by the International Mechanical

Code):

1.1. Correctional cells.

1.2. Daycare sickrooms.

1.3. Science labs.

1.4. Barbers.

1.5. Beauty and nail salons.

1.6. Bowling alley seating.

CE-74 2018 Washington State Energy Code

2. When the space is unoccupied during occupied building hours, a ventilation rate equal to or less than

the zone outdoor airflow as defined in Section 403.3.1.1.1 of the International Mechanical Code with a

zone population of zero.

C403.7.3. Ventilation air heating control. Units that provide ventilation air to multiple zones and operate in

conjunction with zone heating and cooling systems shall not use heating or heat recovery to warm supply air

to a temperature greater than 60°F (16°C) when representative building loads or outdoor air temperature

indicate that the majority of zones require cooling.

C403.7.4 Automatic control of HVAC systems serving guestrooms. In Group R-1 buildings containing

more than 50 guestrooms, each guestroom shall be provided with controls complying with the provisions of

Sections C403.7.4.1 and C403.7.4.2. Card key controls comply with these requirements.

C403.7.4.1 Temperature set point controls. Controls shall be provided on each HVAC system that are

capable of and configured to automatically raise the cooling set point and lower the heating set point by not

less than 4°F (2°C) from the occupant set point within 30 minutes after the occupants have left the

guestroom. The controls shall be capable of and configured to automatically raise the cooling set point to

not lower than 80°F (27°C) and lower the heating set point to not higher than 60°F (16°C) when the

guestroom is unrented or has been continuously unoccupied for over 16 hours or a networked guestroom

control system indicates that the guestroom is unrented and the guestroom is unoccupied for more than 30

minutes. A networked guestroom control system that is capable of returning the thermostat set points to

default occupied set points 60 minutes prior to the time a guestroom is scheduled to be occupied is not

precluded by this section. Cooling that is capable of limiting relative humidity with a set point not lower than

65 percent relative humidity during unoccupied periods is not precluded by this section

C403.7.4.2 Ventilation controls. Controls shall be provided on each HVAC system that are capable of and

configured to automatically turn off the ventilation and exhaust fans within 30 minutes of the occupants

leaving the guestroom, or isolation devices shall be provided to each guestroom that are capable of

automatically shutting off the supply of outdoor air to and exhaust air from the guestroom.

Exception: Guestroom ventilation systems are not precluded from having an automatic daily pre-

occupancy purge cycle that provides daily outdoor air ventilation during unrented periods at the design

ventilation rate for 60 minutes, or at a rate and duration equivalent to one air change.

C403.7.5 Enclosed loading dock and parking garage exhaust ventilation system controls. Mechanical

ventilation systems for enclosed loading docks and parking garages shall be designed to exhaust the airflow

rates (maximum and minimum) determined in accordance with the International Mechanical Code.

Ventilation systems shall be equipped with a control device that operates the system automatically by

means of carbon monoxide detectors applied in conjunction with nitrogen dioxide detectors. Controllers shall

be configured to shut off fans or modulate fan speed to 50 percent or less of design capacity, or intermittently

operate fans less than 20 percent of the occupied time or as required to maintain acceptable contaminant

levels in accordance with the International Mechanical Code provisions.

Gas sensor controllers used to activate the exhaust ventilation system shall stage or modulate fan speed

upon detection of specified gas levels. All equipment used in sensor controlled systems shall be designed for

the specific use and installed in accordance with the manufacturer’s recommendations. The system shall be

arranged to operate automatically by means of carbon monoxide detectors applied in conjunction with

nitrogen dioxide detectors. Garage and loading docks shall be equipped with a controller and a full array of

carbon monoxide (CO) sensors set to maintain levels of carbon monoxide below 35 parts per million (ppm).

Additionally, a full array of nitrogen dioxide detectors shall be connected to the controller set to maintain the

nitrogen dioxide level below the OSHA standard for eight hour exposure.

Spacing and location of the sensors shall be installed in accordance with manufacturer recommendations.

C403.7.5.1 System activation devices for enclosed loading docks. Ventilation systems for enclosed

loading docks shall be activated by one of the following:

1. Gas sensors installed in accordance with the International Mechanical Code; or

2. Occupant detection sensors used to activate the system that detects entry into the loading area along

both the vehicle and pedestrian pathways.

C403.7.5.2 System activation devices for enclosed parking garages. Ventilation systems for enclosed

parking garages shall be activated by gas sensors.

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Exception: A parking garage ventilation system having a total design capacity under 8,000 cfm may use

occupant sensors.

C403.7.6 Energy recovery ventilation systems. Any system with minimum outside air requirements at

design conditions greater than 5,000 cfm or any system where the system’s supply airflow rate exceeds the

value listed in Tables C403.7.6(1) and C403.7.6(2), based on the climate zone and percentage of outdoor

airflow rate at design conditions, shall include an energy recovery system. Table C403.7.6(1) shall be used for

all ventilation systems that operate less than 8,000 hours per year, and Table C403.7.6(2) shall be used for all

ventilation systems that operate 8,000 hours or more per year. The energy recovery system shall have the

capability to provide a change in the enthalpy of the outdoor air supply of not less than 50 percent of the

difference between the outdoor air and return air enthalpies, at design conditions. Where an air economizer

is required, the energy recovery system shall include a bypass of the energy recovery media for both the

outdoor air and exhaust air or return air dampers and controls which permit operation of the air economizer as

required by Section C403.5. Where a single room or space is supplied by multiple units, the aggregate

ventilation (cfm) of those units shall be used in applying this requirement. The return/exhaust air stream

temperature for heat recovery device selection shall be 70°F (21°C) at 30 percent relative humidity, or as

calculated by the registered design professional.

Exception: An energy recovery ventilation system shall not be required in any of the following conditions:

1. Where energy recovery systems are restricted per Section 514 of the International Mechanical Code

to sensible energy, recovery shall comply with one of the following:

1.1. Kitchen exhaust systems where they comply with Section C403.7.7.1.

1.2. Laboratory fume hood systems where they comply with Exception 2 of Section C403.7.6.

1.3. Other sensible energy recovery systems with the capability to provide a change in dry bulb

temperature of the outdoor air supply of not less than 50 percent of the difference between the

outdoor air and the return air dry bulb temperatures, at design conditions.

2. Laboratory fume hood systems that include at least one of the following features and also comply with

Section C403.7.7.2:

2.1. Variable-air-volume hood exhaust and room supply systems capable of reducing exhaust and

makeup air volume to 50 percent or less of design values.

2.2. Direct makeup (auxiliary) air supply equal to at least 75 percent of the exhaust rate, heated no

warmer than 2°F (1.1°C) above room set point, cooled to no cooler than 3°F (1.7°C) below room

set point, no humidification added, and no simultaneous heating and cooling used for

dehumidification control.

3. Systems serving spaces that are heated to less than 60°F (15.5°C) and are not cooled.

4. Where more than 60 percent of the outdoor air heating energy is provided from site-recovered energy.

5. Systems exhausting toxic, flammable, paint or corrosive fumes or dust.

6. Cooling energy recovery in Climate Zones 3C, 4C, 5B, 5C, 6B, 7 and 8.

7. Systems requiring dehumidification that employ energy recovery in series with the cooling coil.

8. Multi-zone systems where the supply airflow rate is less than the values specified in Tables

C403.7.6(1) and C403.7.6(2) for the corresponding percent of outdoor air. Where a value of NR is

listed, energy recovery shall not be required.

9. Equipment which meets the requirements of Section C403.9.2.4.

10. Systems serving Group R-1 and R-3 dwelling or sleeping units where the largest source of air

exhausted at a single location at the building exterior is less than 25 percent of the design outdoor air

flow rate.

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TABLE C403.7.6(1)

ENERGY RECOVERY REQUIREMENT

(VENTILATION SYSTEMS OPERATING LESS THAN 8,000 HOURS PER YEAR)

CLIMATE

ZONE

PERCENT (%) OUTDOOR AIR AT FULL DESIGN AIRFLOW RATE

≥10% and

20%

≥20% and

30%

≥30% and

40%

≥40% and

50%

≥50% and

60%

≥60% and

70%

≥70% and

80%

≥80%

DESIGN SUPPLY FAN AIRFLOW RATE (cfm)

4C, 5B

≥5000

NR = not required

TABLE C403.7.6.1(2)

ENERGY RECOVERY REQUIREMENT

(VENTILATION SYSTEMS OPERATING NOT LESS 8,000 HOURS PER YEAR)

CLIMATE

ZONE

PERCENT (%) OUTDOOR AIR AT FULL DESIGN AIRFLOW RATE

≥10% and

20%

≥20% and

30%

≥30% and

40%

≥40% and

50%

≥50% and

60%

≥60% and

70%

≥70% and

80%

≥80%

DESIGN SUPPLY FAN AIRFLOW RATE (cfm)

≥ 19500

≥ 9000

≥ 5000

≥ 4000

≥ 3000

≥ 1500

≥120

≥ 2500

≥ 2000

≥ 1000

≥ 500

≥ 140

≥ 120

≥ 100

≥ 80

NR = not required

C403.7.7 Exhaust systems.

C403.7.7.1 Kitchen exhaust systems.

C403.7.7.1.1 Replacement air. Replacement air introduced directly into the exhaust hood cavity shall not

be greater than 10 percent of the hood exhaust airflow rate.

C403.7.7.1.2 Kitchen exhaust hood certification and maximum airflow. Where a kitchen or

kitchen/dining facility has a total kitchen hood exhaust airflow rate that is greater than 2,000 cfm, each

hood shall be a factory built commercial exhaust hood listed by a nationally recognized testing laboratory

in compliance with UL 710 and each hood shall have a maximum exhaust rate as specified in Table

C403.7.7.1.2. Where a single hood, or hood section, is installed over appliances with different duty

ratings, the maximum allowable flow rate for the hood or hood section shall be based on the requirements

for the highest appliance duty rating under the hood or hood section.

Exception: Type II dishwasher exhaust hoods that have an exhaust airflow of 1000 cfm or less.

TABLE C403.7.7.1.2

MAXIMUM NET EXHAUST FLOW RATE,

CFM PER LINEAR FOOT OF HOOD LENGTH

TYPE OF HOOD

LIGHT-DUTY

EQUIPMENT

MEDIUM-DUTY

EQUIPMENT

HEAVY-DUTY

EQUIPMENT

EXTRA-HEAVY-

DUTY EQUIPMENT

Wall-mounted canopy

140

210

280

385

Single island

280

350

420

490

Double island (per

side)

175

210

280

385

Eyebrow

175

Backshelf/Pass-over

210

280

For SI: 1 cfm = 0.4719 L/s; 1 foot = 305 mm.

NA = Not Allowed

C403.7.7.1.3 Kitchen exhaust hood system. Where a kitchen or kitchen/dining facility has a total kitchen

hood exhaust airflow rate greater than 2000 cfm, it shall comply with one of the following:

2018 Washington State Energy Code CE-77

1. Not less than 50 percent of all replacement air shall be transfer air that would otherwise be

exhausted.

2. Demand ventilation systems on not less than 75 percent of the total exhaust hood airflow that are

configured to provide not less than a 50 percent reduction in exhaust and replacement air system

airflow rates, including controls necessary to modulate airflow in response to appliance operation

and to maintain full capture and containment of smoke, effluent and combustion products during

cooking and idle.

3. Listed energy recovery devices with a sensible heat recovery effectiveness of not less than 40

percent on not less than 50 percent of the total exhaust hood airflow.

Exceptions:

1. Where not less than 75 percent of all the replacement air is transfer air that would otherwise be

exhausted.

2. UL 710 listed exhaust hoods that have a design maximum exhaust flow rate no greater than 250

cfm per linear foot of hood that serve kitchen or kitchen/dining facilities with a total kitchen hood

exhaust airflow rate less than 5000 cfm.

3. Type II dishwasher exhaust hoods that have an exhaust airflow of 1000 cfm or less.

C403.7.7.2 Laboratory exhaust systems. Buildings with laboratory exhaust systems having a total exhaust

rate greater than 5,000 cfm (2,360 L/s) shall include heat recovery systems to preconditioned replacement

air from laboratory exhaust. The heat recovery system shall be capable of increasing the outside air supply

temperature at design heating conditions by 25°F (13.9°C). A provision shall be made to bypass or control

the heat recovery system to permit air economizer operation as required by Section C403.5.

Exceptions:

1. Variable air volume laboratory exhaust and room supply systems configured to reduce exhaust

and make-up air volume to 50% or less of design values; or

2. Direct make-up (auxiliary) air supply equal to at least 75% of the exhaust rate, heated no warmer

than 2°F (1.1°C) below room set point, cooled to no cooler than 3°F (1.7°C) above room set point,

no humidification added, and no simultaneous heating and cooling used for dehumidification

control; or

3. Combined energy reduction method: VAV exhaust and room supply system configured to reduce

exhaust and makeup air volumes and a heat recovery system to precondition makeup air from

laboratory exhaust that when combined will produce the same energy reduction as achieved by a

heat recovery system with a 50% sensible recovery effectiveness as required above. For

calculation purposes, the heat recovery component can be assumed to include the maximum

design supply airflow rate at design conditions. The combined energy reduction (Q

) shall meet

the following:

≥ Q

MIN

= CFM

- T

)

1.1

0.6

= CFM

- T

)

1.1(A+B)/100

Where:

MIN

= Energy recovery at 60% sensible effectiveness (Btu/h)

= Combined energy reduction (Btu/h)

CFM

= The maximum design supply airflow rate to conditioned spaces served by the

system in cubic feet per minute

= Space return air dry bulb at winter design conditions

= Outdoor air dry bulb at winter design conditions

A = Percentage that the exhaust and makeup air volumes can be reduced from design

conditions

B = Percentage sensible heat recovery effectiveness

C403.7.7.3 Transfer air. Conditioned supply air delivered to any space with mechanical exhaust shall not

exceed the greater of:

1. The supply flow required to meet the space heating or cooling load;

CE-78 2018 Washington State Energy Code

2. The ventilation rate required by the authority having jurisdiction, the facility Environmental Health and

Safety department, or Section C403.2.2; or

3. The mechanical exhaust flow minus the available transfer air from conditioned spaces or return air

plenums that at their closest point are within 15 feet of each other on the same floor that are not in

different smoke or fire compartments. Available transfer air is that portion of outdoor ventilation air

that:

3.1. Is not required to satisfy other exhaust needs,

3.2. Is not required to maintain pressurization of other spaces, and

3.3. Is transferable according to applicable codes and standards and per the International

Mechanical Code.

Exceptions:

1. Laboratories classified as biosafety level 3 or higher.

2. Vivarium spaces.

3. Spaces that are required by applicable codes and standards to be maintained at positive pressure

relative to adjacent spaces. For spaces taking this exception, any transferable air that is not directly

transferred shall be made available to the associated air-handling unit and shall be used whenever

economizer or other options do not save more energy.

4. Spaces where the demand for transfer air may exceed the available transfer airflow rate and where

the spaces have a required negative pressure relationship. For spaces taking this exception, any

transferable air that is not directly transferred shall be made available to the associated air-handling

unit and shall be used whenever economizer or other options do not save more energy.

C403.7.8 Shutoff dampers. Mechanical openings shall be provided with shutoff dampers in accordance with

Sections C403.7.8.1 through C403.7.8.4.

C403.7.8.1 Shutoff dampers for building isolation. Outdoor air supply, exhaust openings and relief

outlets and stairway and elevator hoistway shaft vents shall be provided with Class I motorized dampers.

See Sections C403.10.1 and C403.10.2 for ductwork insulation requirements upstream and downstream of

the shutoff damper.

Exceptions:

1. Gravity (nonmotorized) dampers shall be permitted in lieu of motorized dampers as follows:

1.1. Relief dampers serving systems less than 5,000 cfm total supply shall be permitted in

buildings less than three stories in height.

1.2. Gravity (nonmotorized) dampers where the design outdoor air intake or exhaust capacity does

not exceed 400 cfm (189 L/s).

1.3. Systems serving areas which require continuous operation for 24/7 occupancy schedules.

2. Shutoff dampers are not required in:

2.1. Combustion air intakes.

2.2. Systems serving areas which require continuous operation in animal hospitals, kennels and

pounds, laboratories, and Group H, I and R occupancies.

2.3. Subduct exhaust systems or other systems that are required to operate continuously by the

International Mechanical Code.

2.4. Type I grease exhaust systems or other systems where dampers are prohibited by the

International Mechanical Code to be in the airstream.

2.5. Unconditioned stairwells or unconditioned elevator hoistway shafts that are only connected to

unconditioned spaces.

C403.7.8.2 Shutoff dampers for return air. Return air openings used for airside economizer operation

shall be equipped with Class I motorized dampers.

C403.7.8.3 Damper leakage rating. Class I dampers shall have a maximum leakage rate of 4 cfm/ft

(20.3

L/s

) at 1.0 inch water gauge (w.g.) (249 Pa) when tested in accordance with AMCA 500D and shall be

labeled by an approved agency for such purpose. Gravity (nonmotorized) dampers shall have an air leakage

rate not greater than 20 cfm/ft

where not less than 24 inches (610 mm) in either dimension and 40 cfm/ft

2018 Washington State Energy Code CE-79

where less than 24 inches in either dimension. The rate of air leakage shall be determined at 1.0 inch w.g.

(249 Pa) when tested in accordance with AMCA 500D for such purpose. The dampers shall be labeled by

an approve agency. Gravity dampers for ventilation air intakes shall be protected from direct exposure to

wind.

Exceptions:

1. Gravity (nonmotorized) dampers are not required to be tested to verify the air leakage rating when

installed in exhaust systems where the exhaust capacity does not exceed 400 cfm (189 L/s) and

the gravity damper is provided with a gasketed seal.

2. Motorized dampers on return air openings in unitary packaged equipment that have the minimum

leakage rate available from the manufacturer.

C403.7.8.4 Damper actuation. Outdoor air intake, relief and exhaust shutoff dampers shall be installed

with automatic controls configured to close when the systems or spaces served are not in use or during

unoccupied period warm-up and setback operation, unless the systems served require outdoor or exhaust

air in accordance with the International Mechanical Code or the dampers are opened to provide intentional

economizer cooling. Stairway and elevator hoistway shaft vent dampers shall be installed with automatic

controls configured to open upon the activation of any fire alarm initiating device of the building’s fire alarm

system or the interruption of power to the damper.

C403.8 Fan and fan controls. Fans in HVAC systems shall comply with Sections C403.8.1 through C403.8.5.1.

The airflow requirements of Section C403.8.5.1 shall apply to all fan motors. Group R occupancy exhaust fans

shall also comply with Section C403.8.4.

C403.8.1 Allowable fan motor horsepower. Each HVAC system having a total fan system motor nameplate

horsepower exceeding 5 hp (3.7kW) at fan system design conditions shall not exceed the allowable fan

system motor nameplate hp (Option 1) or fan system bhp (Option 2) as shown in Table C403.8.1(1). This

includes supply fans, exhaust fans, return/relief fans, and fan-powered VAV air terminal units associated with

systems providing heating or cooling capability. Single zone variable-air-volume systems shall comply with the

constant volume fan power limitation. Zone heating and/or cooling terminal units installed in conjunction with a

dedicated outdoor air system (DOAS) shall be evaluated as separate HVAC systems for allowable fan motor

horsepower.

Exceptions:

1. Hospital, vivarium and laboratory systems that utilize flow control devices on exhaust or return to

maintain space pressure relationships necessary for occupant health and safety or environmental

control shall be permitted to use variable volume fan power limitation.

2. Individual exhaust fans with motor nameplate horsepower of 1 hp or less are exempt from the

allowable fan motor horsepower requirements.

TABLE C403.8.1(1)

FAN POWER LIMITATION

LIMIT

CONSTANT VOLUME

VARIABLE VOLUME

Option 1: Fan system

motor nameplate hp

Allowable nameplate motor

hp ≤ CFM

× 0.0011

hp ≤ CFM

× 0.0015

Option 2: Fan system bhp

Allowable fan system bhp

bhp ≤ CFM

× 0.00094 + A

bhp ≤ CFM

× 0.0013 + A

For SI: 1 bhp = 735.5 W, 1 hp = 745.5 W, 1 cfm = 0.471 L/s.

where:

CFM

= The maximum design supply airflow rate to conditioned spaces served by the system in cubic feet per

minute.

Hp = The maximum combined motor nameplate horsepower.

Bhp = The maximum combined fan brake horsepower.

A = Sum of [PD × CFMD / 4131]

where:

PD = Each applicable pressure drop adjustment from Table C403.8.1(2) in. w.c.

CFM

= The design airflow through each applicable device from Table C403.8.1(2) in cubic feet per minute.

CE-80 2018 Washington State Energy Code

TABLE C403.8.1(2)

FAN POWER LIMITATION PRESSURE DROP ADJUSTMENT

Device

Adjustment

Credits

Return air or exhaust system required by code or

accreditation standards to be fully ducted, or systems

required to maintain air pressure differentials between

adjacent rooms

0.5 inch w.c. (2.15 inches w.c. for laboratory and

vivarium systems)

Return and/or exhaust air flow control devices

0.5 inch w.c.

Exhaust filters, scrubbers, or other exhaust treatment

The pressure drop of device calculated at fan system

design condition

Particulate filtration credit: MERV 9 - 12

0.5 inch w.c.

Particulate filtration credit: MERV 13 - 15

0.9 inch w.c.

Particulate filtration credit: MERV 16 and greater and

electronically enhanced filters

Pressure drop calculated at 2x clean filter pressure drop

at fan system design condition

Carbon and other gas-phase air cleaners

Clean filter pressure drop at fan system design

condition

Biosafety cabinet

Pressure drop of device at fan system design condition

Energy recovery device, other than coil runaround loop

For each airstream (2.2 × energy recovery effectiveness

– 0.5 inch w.c.)

Coil runaround loop

0.6 inch w.c. for each airstream

Evaporative humidifier/cooler in series with another

cooling coil

Pressure drop of device at fan system design conditions

Sound attenuation section (fans serving spaces with

design background noise goals below NC35)

0.15 inch w.c.

Exhaust system serving fume hoods

0.35 inch w.c.

Laboratory and vivarium exhaust systems in high-rise

buildings

0.25 inch w.c./100 feet of vertical duct exceeding 75

feet

Deductions

Systems without central cooling device

-0.6 inch w.c.

Systems without central heating device

-0.3 inch w.c.

Systems with central electric resistance heating

-0.2 inch w.c.

For SI: 1 inch w.c. = 249 Pa, 1 inch.= 25.4 mm.

w.c. .= water column, NC = Noise criterion.

C403.8.2 Motor nameplate horsepower. For each fan, the selected fan motor shall be no larger than the

first available motor size greater than the brake horsepower (bhp). The fan bhp shall be indicated on the

design documents to allow for compliance verification by the code official.

Exceptions:

1. For fans less than 6 bhp (4413 W), where the first available motor larger than the brake horsepower

has a nameplate rating within 50 percent of the bhp, selection of the next larger nameplate motor

size is allowed.

2. For fans 6 bhp (4413 W) and larger, where the first available motor larger than the bhp has a

nameplate rating within 30 percent of the bhp, selection of the next larger nameplate motor size is

allowed.

3. For fans used only in approved life safety applications such as smoke evacuation.

4. Fans with motor nameplate horsepower less than 1 hp are exempt from this section.

2018 Washington State Energy Code CE-81

C403.8.3 Fan efficiency. Fans shall have a fan efficiency grade (FEG) of 67 or higher based on

manufacturers’ certified data, as defined by AMCA 205. The total efficiency of the fan at the design point

of operation shall be within 15 percentage points of the maximum total efficiency of the fan.

Exception: The following fans are not required to have a fan efficiency grade:

1. Individual fans with a motor nameplate horsepower of 5 hp (3.7 kW) or less that are not part of a

group operated as the functional equivalent of a single fan.

2. Multiple fans in series or parallel that have a combined motor nameplate horsepower of 5 hp (3.7

kW) or less and are operated as the functional equivalent of a single fan.

3. Fans that are part of equipment covered under Section C403.3.2.

4. Fans included in an equipment package certified by an approved agency for air or energy

performance.

5. Powered wall/roof ventilators.

6. Fans outside the scope of AMCA 205.

7. Fans that are intended to operate only during emergency conditions.

C403.8.4 Group R occupancy exhaust fan efficacy. The Group R occupancies of the building shall be

provided with ventilation that meets the requirements of the International Mechanical Code, as applicable, or

with other approved means of ventilation. Mechanical ventilation system fans with 400 cfm or less in capacity

shall meet the efficacy requirements of Table C403.8.4.

Exceptions:

1. Group R heat recovery ventilator and energy recovery ventilator fans that are less than 400 cfm.

2. Where whole house ventilation fans are integrated with forced-air systems that are tested and listed

HVAC equipment, provided they are powered by an electronically commutated motor where required by

Section C405.8

3. Domestic clothes dryer booster fans, domestic range rood exhaust fans, and domestic range booster

fans that operate intermittently.

TABLE C403.8.4

GROUP R EXHAUST FAN EFFICACY

Fan location

Air Flow Rate

Minimum (cfm)

Minimum

Efficacy

(cfm/watt)

Air Flow Rate

Minimum (cfm)

Exhaust fan: Bathroom,

utility room, whole house

2.8

< 90

Exhaust fan: Bathroom,

utility room, whole house

3.5

Any

In-line (single-port and

multi-port) fans

Any

3.8

Any

C403.8.5 Fan controls. Controls shall be provided for fans in accordance with Section C403.8.5.1 and as

required for specific systems provided in Section C403.

C403.8.5.1 Fan airflow control. Each cooling system listed in Table C403.8.5.1 shall be designed to vary

the indoor fan airflow as a function of load and shall comply with the following requirements:

1. Direct expansion (DX) and chilled water cooling units that control the capacity of the mechanical

cooling directly based on space temperature shall have not fewer than two stages of fan control. Low

or minimum speed shall not be greater than 66 percent of full speed. At low or minimum speed, the

fan system shall draw not more than 40 percent of the fan power at full fan speed. Low or minimum

speed shall be used during periods of low cooling load and ventilation-only operation.

2. Other units including DX cooling units and chilled water units that control the space temperature by

modulating the airflow to the space shall have modulating fan control. Minimum speed shall be not

greater than 50 percent of full speed. At minimum speed, the fan system shall draw no more than 30

percent of the power at full fan speed. Low or minimum speed shall be used during periods of low

cooling load and ventilation-only operation.

3. Units that include an airside economizer in accordance with Section C403.5 shall have not fewer

than two speeds of fan control during economizer operation.

CE-82 2018 Washington State Energy Code

Exceptions:

1. Modulating fan control is not required for chilled water and evaporative cooling units with fan

motors of less than 1 hp (0.746 kW) where the units are not used to provide ventilation air and the

indoor fan cycles with the load.

2. Where the volume of outdoor air required to comply with the ventilation requirements of the

International Mechanical Code at low speed exceeds the air that would be delivered at the

minimum speed defined in Section C403.8.5, the minimum speed shall be selected to provide the

required ventilation air.

TABLE C403.8.5.1

FAN CONTROL

Cooling System

Type

Fan Motor

Size

Mechanical

Cooling

Capacity

DX cooling

Any

≥ 42,000 Btu/h

Chilled water and

evaporative

cooling

≥ ¼ hp

Any

◄

C403.9 Heat rejection and heat recovery equipment.

C403.9.1 Heat rejection equipment. Heat rejection equipment, including air-cooled condensers, dry coolers,

open-circuit cooling towers, closed-circuit cooling towers and evaporative condensers, shall comply with this

section.

Exception: Heat rejection devices where energy use is included in the equipment efficiency ratings listed in

Tables C403.3.2(1)A, C403.3.2(1)B, C403.3.2(1)C, C403.3.2(2), C403.3.2(3), C403.3.2(7) and C403.3.2(9).

Heat rejection equipment shall have a minimum efficiency performance not less than values specified in Table

C403.3.2(8).

C403.9.1.1 Fan speed control. Each fan powered by an individual motor or array of motors with a connected

power, including the motor service factor, totaling 5 hp (3.7 kW) or more shall have controls and devices

configured to automatically modulate the fan speed to control the leaving fluid temperature or condensing

temperature and pressure of the heat rejection device. Fan motor power input shall be not more than 30

percent of design wattage at 50 percent of the design airflow.

Exceptions:

1. Fans serving multiple refrigerant or fluid cooling circuits.

2. Condenser fans serving flooded condensers.

C403.9.1.2 Multiple-cell heat rejection equipment. Multiple-cell heat rejection equipment with variable

speed fan drives shall be controlled to operate the maximum number of fans allowed that comply with the

manufacturer's requirements for all system components and so that all fans can operate at the same fan

speed required for the instantaneous cooling duty, as opposed to staged (on/off) operation. The minimum fan

speed shall be the minimum allowable speed of the fan drive system in accordance with the manufacturer's

recommendations.

C403.9.1.3 Limitation on centrifugal fan open-circuit cooling towers. Centrifugal fan open-circuit cooling

towers with a combined rated capacity of 1,100 gpm (4164 L/m) or greater at 95°F (35°C) condenser water

return, 85°F (29°C) condenser water supply, and 75°F (24°C) outdoor air wet-bulb temperature shall meet the

energy efficiency requirement for axial fan open-circuit cooling towers listed in Table C403.3.2(8).

C403.9.1.4 Tower flow turndown. Open-circuit cooling towers used on water-cooled chiller systems that are

configured with multiple- or variable-speed condenser water pumps shall be designed so that all open circuit

cooling tower cells can be run in parallel with the larger of the flow that is produced by the smallest pump at its

minimum expected flow rate or at 50 percent of the design flow for the cell.

C403.9.2 Heat recovery.

C403.9.2.1 Heat recovery for service water heating. Condenser heat recovery shall be installed for

heating or reheating of service hot water provided the facility operates 24 hours a day, the total installed

heat capacity of water cooled systems exceeds 1,500,000 Btu/hr of heat rejection, and the design service

2018 Washington State Energy Code CE-83

water heating load exceeds 250,000 Btu/hr.

The required heat recovery system shall have the capacity to provide the smaller of:

1. Sixty percent of the peak heat rejection load at design conditions; or

2. The preheating required to raise the peak service hot water draw to 85°F (29°C).

Exceptions:

1. Facilities that employ condenser heat recovery for space heating or reheat purposes with a heat

recovery design exceeding 30 percent of the peak water-cooled condenser load at design

conditions.

2. Facilities that provide 60 percent of their service water heating from site recovered energy.

C403.9.2.2 Steam condensate systems. On-site steam heating systems shall have condensate water heat

recovery. On-site includes a system that is located within or adjacent to one or more buildings within the

boundary of a contiguous area or campus under one ownership and which serves one or more of those

buildings.

Buildings using steam generated off-site with steam heating systems which do not have condensate water

recovery shall have condensate water recovery.

C403.9.2.3 Refrigeration condenser heat recovery. Facilities having food service, meat or deli

departments and having 500,000 Btu/h or greater of remote refrigeration condensers shall have condenser

waste heat recovery from freezers and coolers and shall use the waste heat for service water heating,

space heating or for dehumidification reheat. Facilities having a gross conditioned floor area of 40,000 ft

greater and 1,000,000 Btu/h or greater of remote refrigeration shall have condenser waste heat recovery

from freezers and coolers and shall use the waste heat for service water heating, and either for space

heating or for dehumidification reheat for maintaining low space humidity.

C403.9.2.4 Heat recovery for space heating. A water-source condenser heat recovery system meeting the

requirements of Sections C403.9.2.4.1 through C403.9.2.4.4 shall be installed to serve space and

ventilation heating systems in new buildings and additions meeting the following criteria:

1. The facility operates greater than 70 hours per week.

2. The sum of all heat rejection equipment capacity serving the new building or addition exceeds

1,500,000 BTU/hr.

3. The sum of zone minimum airflows in all zones with zone reheat coils divided by the conditioned floor

area served by those systems is at least 0.45 cfm per square foot.

Exception: Systems complying with Section C403.3.5, Dedicated outdoor air systems (DOAS).

C403.9.2.4.1 Water to water heat recovery. Ninety percent (90%) of the total building space and

ventilation heating system design load shall be served by systems that include heat recovery chiller or

water to water heat pump equipment capable of rejecting heat from the cooling loop to the space and

ventilation heating loop as the first stage of heating.

C403.9.2.4.2 Exhaust heat recovery. Heat shall be recovered by the heat recovery system from 90

percent of the total building exhaust airflow. The maximum leaving air temperature of exhaust air after

heat recovery shall be 55°F dry-bulb when operating at full capacity in heat recovery mode.

Exceptions:

1. Where energy recovery systems are restricted by Section 514 of the International Mechanical

Code to sensible energy, those systems shall not be included in the calculation of total building

exhaust airflow.2. Exhaust air systems handling contaminated airstreams that are regulated by

applicable codes or accreditation standards and pose a health risk to maintenance personnel to

maintain heat recovery devices, those systems shall not be included in the calculation of total

building exhaust airflow.

C403.9.2.4.3 Process heat recovery. Spaces with year-round cooling loads from lights and equipment of

5 watts and greater per square foot shall be served by water-cooled equipment. Cooling loops serving the

water-cooled equipment shall be served by water source heat recovery systems meeting the requirements

of Section C403.9.2.4.1. If such spaces are provided with an air or water economizer, the economizer

controls shall be configured with an override signal from the building automation system to disable

economizer operation during heat recovery mode.

C403.9.2.4.4 Water to water heat recovery sizing. The minimum total combined capacity of heat

recovery chillers or water to water heat pumps shall match the total combined capacity of installed

CE-84 2018 Washington State Energy Code

equipment sized to meet the requirements of Sections C403.9.2.4.2 and C403.9.2.4.3.

C403.10 Construction of HVAC system elements. Ducts, plenums, piping and other elements that are part of

an HVAC system shall be constructed and insulated in accordance with Sections C403.10.1 through

C403.10.3.1

C403.10.1 Duct and plenum insulation and sealing.

C403.10.1.1 Ducts conveying outdoor air. Ducts, shafts and plenums conveying outdoor air from the

exterior of the building to the mechanical system shall meet all air leakage and building envelope insulation

requirements of Section C402, plus building envelope vapor control requirements from the International

Building Code, extending continuously from the building exterior to an automatic shutoff damper or heating

or cooling equipment. For the purposes of building envelope insulation requirements, duct surfaces shall be

insulated with the minimum insulation values in Table C403.10.1.1. Duct surfaces included as part of the

building envelope shall not be used in the calculation of maximum glazing area as described in Section

C402.4.1.

Exceptions:

1. Outdoor air ducts serving individual supply air units with less than 2,800 cfm of total supply air

capacity, provided these are insulated to the minimum insulation values in Table C403.10.1.1.

2. Unheated equipment rooms with combustion air louvers, provided they are isolated from

conditioned space at sides, top and bottom of the room with R-11 nominal insulation.

TABLE C403.10.1.1

OUTDOOR AIR DUCTWORK INSULATION

Duct

system

Duct Location and

Use

Climate

Zone

Airflow

Minimum

Installed

Duct

Insulation

R-value

a,b

Notes

Outdoor Air

Inside conditioned

space and upstream of

automatic shutoff

damper

4C and

≥ 2800 CFM

R-16

See Section C403.10.1.1

for additional

requirements

Outdoor Air

Inside conditioned

space and downstream

of automatic shutoff

damper to HVAC unit or

room

≥ 2800 CFM

R-8

Outdoor Air

Inside conditioned

space and downstream

of automatic shutoff

damper to HVAC unit or

room

≥ 2800 CFM

R-12

Outdoor Air

Inside conditioned

space

4C and

< 2800 CFM

R-7

See Exception 1 to

Section C403.10.1.1 for

additional details

a. Insulation R-values, measured in h·ft

·°F/Btu, are for the insulation as installed and do not include film

resistance. The required minimum thicknesses do not consider water vapor transmission and possible

surface condensation. Insulation resistance measured on a horizontal plane in accordance with ASTM C518

at a mean temperature of 75°F at the installed thickness.

b. See International Mechanical Code Sections 603.12 and 604 for further details on duct insulation

requirements.

C403.10.1.2 Other supply and return ducts. All other supply and return air ducts and plenums shall be

insulated with a minimum of R-6 insulation where located in unconditioned spaces, and where located

outside the building with a minimum of R-8 insulation in Climate Zone 4 and R-12 insulation in Climate Zone

5. Where located within a building envelope assembly, the duct or plenum shall be separated from the

building exterior or unconditioned or exempt spaces by minimum insulation value as required for exterior

walls by Section C402.1.3.

2018 Washington State Energy Code CE-85

Exceptions:

1. Where located within equipment.

2. Supply and return ductwork located in unconditioned spaces where the design temperature

difference between the interior and exterior of the duct or plenum does not exceed 15°F (8°C) and

insulated in accordance with Table C403.10.1.2.

Where located within conditioned space, supply ducts which convey supply air at temperatures less than

55°F or greater than 105°F shall be insulated with a minimum insulation R-value in accordance with Table

C403.10.1.2.

Exception: Ductwork exposed to view within a zone that serves that zone is not required to be insulated.

Where located within conditioned space, return or exhaust air ducts that convey return or exhaust air

downstream of an energy recovery media shall be insulated with a minimum R-value in accordance with

Table C403.10.1.2.

All ducts, air handlers, and filter boxes shall be sealed. Joints and seams shall comply with Section 603.9

of the International Mechanical Code.

TABLE C403.10.1.2

SUPPLY, RETURN, EXHAUST, and RELIEF AIR DUCTWORK INSULATION

Duct system

Duct Location and Use

Climate

Zone

Minimum

Installed

Duct

Insulation

R-value

a,b

Notes

Supply Air or Return

Air

Outside the building (outdoors and

exposed to weather)

R-8

See Section C403.10.1.2 for

details

Supply Air or Return

Air

Outside the building (outdoors and

exposed to weather)

R-12

See Section C403.10.1.2 for

details

Supply Air or Return

Air

Unconditioned space (enclosed but

not in the building conditioned

envelope)

4C and

R-6

See Section C403.10.1.2 for

details

Supply Air or Return

Air

Unconditioned space where the duct

conveys air that is within 15°F of the

air temperature of the surrounding

unconditioned space

4C and

R-3.3

See IMC Section 603.12 for

additional requirements for

condensation control at

ductwork

Supply Air or Return

Air

Where located in a building envelope

assembly

4C and

R-16

Duct or plenum is separated

from building envelope

assembly with the minimum

insulation value

Supply Air

Within conditioned space where the

supply duct conveys air that is less

than 55°F or greater than 105°F

4C and

R-3.3

See Section C403.10.1.2 for

details

Supply Air

Within conditioned space that the duct

directly serves where the supply duct

conveys air that is less than 55°F or

greater than 105°F

4C and

None

See Section C403.10.1.2 for

details

Supply Air

Within conditioned space where the

supply duct conveys air that is 55 °F

or greater and 105 °F or less

4C and

None

Return or Exhaust

Air

Within conditioned space,

downstream of an energy recovery

media, upstream of an automatic

shutoff damper

R-8

Return or Exhaust

Air

Within conditioned space,

downstream of an energy recovery

media, upstream of an automatic

shutoff damper

R-12

Relief or Exhaust Air

Conditioned space and downstream

4C and

R-16

CE-86 2018 Washington State Energy Code

of an automatic shutoff damper

a. Insulation R-values, measured in h·ft

·°F/Btu, are for the insulation as installed and do not include film

resistance. The required minimum thicknesses do not consider water vapor transmission and possible

surface condensation. Insulation resistance measured on a horizontal plane in accordance with ASTM C518

at a mean temperature of 75°F at the installed thickness.

b. See International Mechanical Code Sections 603.12 and 604 for further details on duct insulation

requirements.

c. Includes attics above insulated ceilings, parking garages and crawl spaces.

C403.10.2 Duct construction. Ductwork shall be constructed and erected in accordance with the

International Mechanical Code.

C403.10.2.1 Low-pressure duct systems. Longitudinal and transverse joints, seams and connections of

supply and return ducts operating at a static pressure less than or equal to 2 inches water gauge (w.g.) (500

Pa) shall be securely fastened and sealed with welds, gaskets, mastics (adhesives), mastic-plus embedded-

fabric systems or tapes installed in accordance with the manufacturer's installation instructions. Pressure

classifications specific to the duct system shall be clearly indicated on the construction documents in

accordance with the International Mechanical Code.

Exception: Continuously welded and locking-type longitudinal joints and seams on ducts operating at

static pressures less than 2 inches water gauge (w.g.) (500 Pa) pressure classification.

C403.10.2.2 Medium-pressure duct systems. Ducts and plenums designed to operate at a static pressure

greater than 2 inches water gauge (w.g.) (500 Pa) but less than 3 inches w.g. (750 Pa) shall be insulated

and sealed in accordance with Section C403.10.1. Pressure classifications specific to the duct system shall

be clearly indicated on the construction documents in accordance with the International Mechanical Code.

C403.10.2.3 High-pressure duct systems. Ducts designed to operate at static pressures equal to or

greater than 3 inches water gauge (w.g.) (750 Pa) shall be insulated and sealed in accordance with Section

C403.10.1. In addition, ducts and plenums shall be leak-tested in accordance with the SMACNA HVAC Air

Duct Leakage Test Manual and shown to have a rate of air leakage (CL) less than or equal to 4.0 as

determined in accordance with Equation 4-9.

CL = F/P

0.65

(Equation 4-9)

Where:

F = The measured leakage rate in cfm per 100 square feet of duct surface.

P = The static pressure of the test.

Documentation shall be furnished by the designer demonstrating that representative sections totaling

at least 25 percent of the duct area have been tested and that all tested sections meet the requirements of

this section.

C403.10.3 Piping insulation. All piping serving as part of a heating or cooling system shall be thermally

insulated in accordance with Table C403.10.3.

Exceptions:

1. Factory-installed piping within HVAC equipment tested and rated in accordance with a test procedure

referenced by this code.

2. Factory-installed piping within room fan-coils and unit ventilators tested and rated according to AHRI

440 (except that the sampling and variation provisions of Section 6.5 shall not apply) and 840,

respectively.

3. Piping that conveys fluids that have a design operating temperature range between 60°F (15°C) and

105°F (41°C).

4. Piping that conveys fluids that have not been heated or cooled through the use of fossil fuels or

electric power.

5. Strainers, control valves, and balancing valves associated with piping 1 inch (25 mm) or less in

diameter.

6. Direct buried piping that conveys fluids at or below 60°F (15°C).

2018 Washington State Energy Code CE-87

TABLE C403.10.3

MINIMUM PIPE INSULATION THICKNESS (thickness in inches)

FLUID

OPERATING

TEMPERATURE

RANGE AND

USAGE (F)

INSULATION CONDUCTIVITY

NOMINAL PIPE OR TUBE SIZE (inches)

Conductivity

Btu · in./(h · ft

· F)

Mean Rating

Temperature, F

1

1 to 1-

1/2

1-1/2 to

4

4 to 8

≥8

> 350

0.32 – 0.34

250

4.5

5.0

251 – 350

0.29 – 0.32

200

3.0

4.0

4.5

201 – 250

0.27 – 0.30

150

2.5

3.0

141 – 200

0.25 – 0.29

125

1.5

2.0

105 – 140

0.21 – 0.28

100

1.0

1.5

40 – 60

0.21 – 0.27

0.5

1.0

< 40

0.20 – 0.26

0.5

1.0

1.5

a. For piping smaller than 1-1/2 inch (38 mm) and located in partitions within conditioned spaces, reduction of these

thicknesses by 1 inch (25 mm) shall be permitted (before thickness adjustment required in footnote b) but not to a

thickness less than 1 inch (25 mm).

b. For insulation outside the stated conductivity range, the minimum thickness (T) shall be determined as follows:

T = r{(1 + t/r)

K/k

– 1}

where:

T = minimum insulation thickness,

r = actual outside radius of pipe,

t = insulation thickness listed in the table for applicable fluid temperature and pipe size,

K = conductivity of alternate material at mean rating temperature indicated for the applicable fluid temperature (Btu ×

in/h × ft2 × °F) and

k = the upper value of the conductivity range listed in the table for the applicable fluid temperature.

c. For direct-buried heating and hot water system piping, reduction of these thicknesses by 11/2 inches (38 mm) shall be

permitted (before thickness adjustment required in footnote b but not to thicknesses less than 1 inch (25 mm).

C403.10.3.1 Protection of piping insulation. Piping insulation exposed to weather shall be protected from

damage, including that due to sunlight, moisture, equipment maintenance and wind, and shall provide

shielding from solar radiation that can cause degradation of the material. Adhesives tape shall not be

permitted.

C403.11 Mechanical systems located outside of the building thermal envelope. Mechanical systems

providing heat outside of the thermal envelope of a building shall comply with Section C403.11.1 through

C403.11.3.

C403.11.1 Heating outside a building. Systems installed to provide heat outside a building shall be radiant

systems.

Such heating systems shall be controlled by an occupancy sensing device or a timer switch, so that the

system is automatically deenergized when no occupants are present.

C403.11.2 Snow- and ice-melt system controls. Snow- and ice-melting systems, supplied through energy

service to the building, shall include automatic controls configured to shut off the system when the pavement

temperature is above 50°F (10°C) and no precipitation is falling and an automatic control that is configured to

shut off when the outdoor temperature is above 40°F (4°C) so that the potential for snow or ice accumulation

is negligible.

C403.11.3 Freeze protection system controls. Freeze protection systems, such as heat tracing of outdoor

piping and heat exchangers, including self-regulating heat tracing, shall include automatic controls configured

to shut off the systems when outdoor air temperatures are above 40°F (4°C) or when the conditions of the

protected fluid will prevent freezing.

C403.12 High efficiency single-zone variable air volume (VAV) systems. For HVAC systems subject to the

requirements of Section C403.3.5 but utilizing Exception 2 of that section, a high efficiency single-zone VAV

system may be provided without a separate parallel DOAS when the system is designed, installed, and

configured to comply with all of the following criteria (this exception shall not be used as a substitution for a

DOAS per Section C406.6 or as a modification to the requirements for the Standard Reference Design in

accordance with Section C407):

CE-88 2018 Washington State Energy Code

1. The single-zone VAV system is provided with airside economizer in accordance with Section 403.3 without

exceptions.

2. A direct-digital control (DDC) system is provided to control the system as a single zone in accordance with

Section C403.4.11 regardless of sizing thresholds of Table C403.4.11.1.

3. Single-zone VAV systems with a minimum outdoor air requirement of 1,000 cfm (472 L/s) or greater shall be

equipped with a device capable of measuring outdoor airflow intake under all load conditions. The system

shall be capable of increasing or reducing the outdoor airflow intake based on Section C403.7.1, Demand

controlled ventilation.

4. Allowable fan motor horsepower shall not exceed 90 percent of the allowable HVAC fan system bhp (Option

2) as defined by Section C403.8.1.1.

5. Each single-zone VAV system shall be designed to vary the supply fan airflow as a function of heating and

cooling load and minimum fan speed shall not be more than the greater of:

5.1. 30 percent of peak design airflow; or

5.2. The required ventilation flow assuming no occupants.

6. Spaces that are larger than 150 square feet (14 m

) and with an occupant load greater than or equal to 25

people per 1000 square feet (93 m

) of floor area (as established in Table 403.3.1.1 of the International

Mechanical Code) shall be provided with all of the following features:

6.1. Demand control ventilation (DCV) shall be provided that utilizes a carbon dioxide sensor to reset the

ventilation set point of the single-zone VAV system from the design minimum to design maximum

ventilation rate as required by Chapter 4 of the International Mechanical Code.

6.2. Occupancy sensors shall be provided that are configured to reduce the minimum ventilation rate to

zero and setback room temperature set points by a minimum of 5°F, for both cooling and heating, when

the space is unoccupied.

7. Single-zone VAV systems shall comply with one of the following options:

7.1. Single-zone VAV air handling units with a hydronic heating coil connected to systems with hot water

generation equipment limited to the following types of equipment: gas-fired hydronic boilers with a

thermal efficiency, E

, of not less than 92 percent, air-to-water heat pumps or heat recovery chillers.

Hydronic heating coils shall be sized for a maximum entering hot water temperature of 120°F for peak

anticipated heating load conditions.

7.2. Single-zone VAV air handing units with a chilled water coil connected to systems with chilled water

generation equipment with IPLV values more than 25 percent higher than the minimum part load

efficiencies listed in Table C403.3.2(7), in the appropriate size category, using the same test

procedures. Equipment shall be listed in the appropriate certification program to qualify. The smallest

chiller or compressor in the central plant shall not exceed 20 percent of the total central plant cooling

capacity or the chilled water system shall include thermal storage sized for a minimum of 20 percent of

the total central cooling plant capacity.

7.3. Single-zone VAV air handling units with DX cooling, heat pump heating or gas-fired furnace shall

comply with the following requirements as applicable:

7.3.1. Have a DX cooling coil with cooling part load efficiency that are a minimum of 15 percent higher

than the minimum SEER or IEER listed in Tables C403.3.2(1) and C403.3.2(2).

7.3.2. Have a gas-fired furnace with a thermal efficiency, Et, of not less than 90 percent or heat pump

with a minimum heating HSPF or COP efficiency that are a minimum of 10 percent higher than the

minimum heating efficiency in Tables C403.3.2(1) and C403.3.2(2).

7.3.3. Heating coils or burner output shall be modulating or have a minimum of 2 stages with the first

stage being less than 50 percent of total heating capacity. Cooling coils shall be modulating or

have a minimum of 2 stages with the first stage being less than 50 percent of the total cooling

capacity.

8. The DDC system shall include a fault detection and diagnostics (FDD) system complying with the following:

8.1. The following temperature sensors shall be permanently installed to monitor system operation:

8.1.1. Outside air.

8.1.2. Supply air.

8.1.3. Return air.

8.2. Temperature sensors shall have an accuracy of ±2°F (1.1°C) over the range of 40°F to 80°F (4°C to

26.7°C).

2018 Washington State Energy Code CE-89

8.3. The single-zone VAV air handling unit controller shall be configured to provide system status by

indicating the following:

8.3.1. Free cooling available.

8.3.2. Economizer enabled.

8.3.3. Compressor enabled.

8.3.4. Heating enabled.

8.3.5. Mixed air low limit cycle active.

8.3.6. The current value of each sensor.

8.4. The single-zone VAV air handling unit controller shall be capable of manually initiating each operating

mode so that the operation of compressors, economizers, fans and the heating system can be

independently tested and verified.

8.5. The single-zone VAV air handling unit shall be configured to report faults to a fault management

application able to be accessed by day-to-day operating or service personnel or annunciated locally on

zone thermostats.

8.6. The FDD system shall be configured to detect the following faults:

8.6.1. Air temperature sensor failure/fault.

8.6.2. Not economizing when the unit should be economizing.

8.6.3. Economizing when the unit should not be economizing.

8.6.4. Outdoor air or return air damper not modulating.

8.6.5. Excess outdoor air.

C403.13 Commissioning. Mechanical systems shall be commissioned in accordance with Section C408.

SECTION C404

SERVICE WATER HEATING AND PRESSURE-BOOSTER SYSTEMS

C404.1 General. This section covers the minimum efficiency of, and controls for, service water-heating

equipment and insulation of service hot water piping.

C404.2 Service water-heating equipment performance efficiency. Water-heating equipment and hot water

storage tanks shall meet the requirements of Table C404.2. The efficiency shall be verified through certification

and listed under an approved certification program, or if no certification program exists, the equipment efficiency

ratings shall be supported by data furnished by the manufacturer. Water-heating equipment intended to be used

to provide space heating shall meet the applicable provisions of Table C404.2.

TABLE C404.2

MINIMUM PERFORMANCE OF WATER-HEATING EQUIPMENT

EQUIPMENT TYPE

SIZE CATEGORY

(input)

SUBCATEGORY OR

RATING CONDITION

PERFORMANCE

REQUIRED

a, b

TEST PROCEDURE

Water heaters,

electric

≤ 12 kW

Tabletop

, ≥20 gal

and <120 gal

0.93 – 0.00132V, EF

DOE 10 CFR Part

430

Resistance ≥20 gal

and ≤55 gal

0.960 - 0.0003V, EF

Grid-enabled

>75 gal

and ≤120 gal

1.06-0.00168V, EF

> 12 kW

Resistance ≥20 gal

(0.3 + 27)/V

%/h

Section G.2 of ANSI

Z21.10.3

≤ 24 amps and

≤ 250 volts

Heat pump

2.057 – 0.00113V, EF

DOE 10 CFR Part

430

Instantaneous

water heaters, electric

All

Resistance

0.93 - 0.00132V, EF

DOE 10 CFR Part

430

CE-90 2018 Washington State Energy Code

TABLE C404.2 (continued)

MINIMUM PERFORMANCE OF WATER-HEATING EQUIPMENT

EQUIPMENT TYPE

SIZE CATEGORY

(input)

SUBCATEGORY OR

RATING CONDITION

PERFORMANCE

REQUIRED

a, b

TEST PROCEDURE

Storage water

heaters, gas

≤ 75,000 Btu/h

≥ 20 gal and ≤ 55 gal

0.675 - 0.0015V, EF

DOE 10 CFR Part

430

>55 gal and ≤100 gal

0.8012 – 0.00078V, EF

> 75,000 Btu/h

< 4,000 Btu/h/gal

80% Et

(Q/800 +110√V)SL,

Btu/h

Section G.1 and G.2

of ANSI Z21.10.3

Instantaneous

water heaters, gas

> 50,000 Btu/h and

< 200,000 Btu/h

≥ 4,000 (Btu/h)/gal

and

< 2 gal

0.82 - 0.0019V, EF

DOE 10 CFR Part

430

≥ 200,000 Btu/h

≥ 4,000 Btu/h/gal and

< 10 gal

80% Et

Section G.1 and G.2

of ANSI Z21.10.3

≥ 200,000 Btu/h

≥ 4,000 Btu/h/gal and

≥10 gal

80% Et

(Q/800 +110√V)SL,

Btu/h

Storage water

heaters, oil

≤ 105,000 Btu/h

≥20 gal

0.68 - 0.0019V, EF

DOE 10 CFR Part

430

> 105,000 Btu/h

< 4,000 Btu/h/gal

80% Et

(Q/800 +110√V)SL,

Btu/h

Section G.1 and G.2

of ANSI Z21.10.3

Instantaneous

water heaters, oil

≤ 210,000 Btu/h

≥ 4,000 Btu/h/gal and

< 2 gal

0.59 - 0.0019V, EF

DOE 10 CFR Part

430

> 210,000 Btu/h

≥ 4,000 Btu/h/gal and

< 10 gal

80% Et

Section G.1 and G.2

of ANSI Z21.10.3

> 210,000 Btu/h

≥ 4,000 Btu/h/gal and

≥10 gal

78% Et

(Q/800 +110√V)SL,

Btu/h

Hot water supply

boilers, gas and oil

≥ 300,000 Btu/h and

< 12,500,000 Btu/h

≥ 4,000 Btu/h/gal and

< 10 gal

80% Et

Section G.1 and G.2

of ANSI Z21.10.3

Hot water supply

boilers, gas

≥ 300,000 Btu/h and

< 12,500,000 Btu/h

≥4,000 Btu/h/gal and

≥10 gal

80% Et

(Q/800 +110√V)SL,

Btu/h

Hot water supply

boilers, oil

≥ 300,000 Btu/h and

< 12,500,000 Btu/h

≥ 4,000 Btu/h/gal and

> 10 gal

78% Et

(Q/800 +110√V)SL,

Btu/h

Pool heaters, gas and

oil

All

—

82% Et

ASHRAE 146

Heat pump pool

heaters

All

—

4.0 COP

AHRI 1160

Unfired storage tanks

All

—

Minimum insulation

requirement R-12.5

(h x ft

x °F)/Btu

(none)

For SI: °C = [(°F) - 32]/1.8, 1 British thermal unit per hour = 0.2931 W, 1 gallon = 3.785 L, 1 British thermal unit per hour per

gallon = 0.078 W/L.

a. Energy factor (EF) and thermal efficiency (Et ) are minimum requirements. In the EF equation, V is the rated volume

in gallons.

b. Standby loss (SL) is the maximum Btu/h based on a nominal 70°F temperature difference between stored water and

ambient requirements. In the SL equation, Q is the nameplate input rate in Btu/h. In the SL equation for electric water

heaters, V is the rated volume in gallons and V

is the measured volume in gallons. In the SL equation for oil and gas

water heaters and boilers, V is the rated volume in gallons.

c. Instantaneous water heaters with input rates below 200,000 Btu/h must comply with these requirements if the water

heater is designed to heat water to temperatures 180°F or higher.

2018 Washington State Energy Code CE-91

d. Electric water heaters with an input rating of 12kW (40,950 Btu/h) or less that are designed to heat water to

temperatures of 180°F or greater shall comply with the requirements for electric water heaters that have an input

rating greater than 12 kW.

e. A tabletop water heater is a water heater that is enclosed in a rectangular cabinet with a flat top surface not more than

three feet (0.91 m) in height.

f. A grid-enabled water heater is an electric resistance water heater that meets all of the following:

1. Has a rated storage tank volume of more than 75 gallons.

2. Is manufactured on or after April 16, 2015.

3. Is equipped at the point of manufacture with an activation lock.

4. Bears a permanent label applied by the manufacturer that complies with all of the following:

4.1 Is made of material not adversely affected by water.

4.2 Is attached by means of non-water soluble adhesive.

4.3 Advises purchasers and end-users of the intended and appropriate use of the product with the following

notice printed in 16.5 point Arial Narrow Bold font: “IMPORTANT INFORMATION: This water heater is

intended only for use as a part of an electric thermal storage or demand response program. It will not

provide adequate hot water unless enrolled in such a program and activated by your utility company or

another program operator. Confirm the availability of a program in your local area before purchasing or

installing this product.”

g. %/h is the energy consumed to replace the heat lost from the tank while on standby, expressed as a percentage of the

total energy in the stored water per hour.

C404.2.1 High input-rated service water heating systems for other than Group R-1 and R-2

occupancies. In new buildings where the combined input rating of the water-heating equipment installed in a

building is equal to or greater than 1,000,000 Btu/h (293 kW), the combined input-capacity-weighted-average

efficiency of water-heating equipment shall be no less than the following for each water heating fuel source:

1. Electric: A rated COP of not less than 2.0. For air-source heat pump equipment, the COP rating will be

reported at the design leaving heat pump water temperature with an entering air temperature of 60°F

(15.6°C) or less.

2. Fossil Fuel: A rated E

of not less than 90 percent as determined by the applicable test procedures in

Table C404.2.

Exceptions:

1. Where not less than 25 percent of the annual service water-heating requirement is provided from any of the

following sources:

1.1. Renewable energy generated on site that is not being used to satisfy another requirement of this code;

1.2. Site recovered energy that is not being used to satisfy other requirements of this code.

2. Redundant equipment intended to only operate during equipment failure or periods of extended

maintenance.

3. Electric resistance heated systems installed as part of an alteration where the water heating equipment is

installed at the grade level in a building with a height of four stories or greater.

4. Hot water heat exchangers used to provide service water heating from a district utility (steam, heating hot

water).

5. Water heaters provided as an integral part of equipment intended to only heat or boost the heat of water

used by that equipment.

6. For electric heat systems, supplemental water heaters not meeting this criteria that function as auxiliary

heating only when the outdoor temperature is below 32°F (0°C) or when a defrost cycle is required are not

required to have a rated COP of 2.0. Such systems shall be sized and configured to lock out electric

resistance or fossil fuel heating from operation when the outdoor temperature is above 32°F (0°C) unless

the system is in defrost operation.

C404.2.2 High input-rated service water heating system for Group R-1 and R-2 occupancies. In new

buildings with over 1,000,000 Btu/h installed service water heating capacity serving Group R-1 and R-2

occupancies, at least 25 percent of annual water heating energy shall be provided from any combination of

the following water heating sources:

CE-92 2018 Washington State Energy Code

1. Renewable energy generated on site that is not being used to satisfy other requirements of this code;

2. Site-recovered energy that is not being used to satisfy other requirements of this code.

Exception: Compliance with this section is not required if the combined input-capacity-weighted average

equipment rating for each service water heating fuel source type is not less than the following:

1. Electric Resistance: An electric resistance water heater water with a rating of 105% of the rated

efficiency of Table C404.2.

2. Electric Heat Pump (10 CFR Part 430): A heat pump water heater rated in accordance with 10 CFR

Part 430 with a rating of 105% of the rated efficiency of Table C404.2.

3. Electric Heat Pump (not listed in accordance with 10 CFR Part 430): A heat pump water heater not

rated in accordance with 10 CFR Part 430 shall have a COP of not less than 2.0. For air-source heat

pump equipment the COP rating will be reported at the design leaving heat pump water temperature

with an entering air temperature of 60°F (15.6°C) or less. Supplemental water heaters not meeting the

above criteria that function as auxiliary heating only when the outdoor temperature is below 32°F (0°)

or when a defrost cycle is required are not required to have a rated COP of 2.0. Such systems shall

be sized and configured to lock out electric resistance or fossil fuel heating from operation when the

outdoor temperature is above 32°F (0°C) unless the system is in defrost operation.

4. Fossil Fuels: A rated E

of not less than 90% as determined by the applicable test procedures in Table

C404.2.

5. Hot water heat exchangers used to provide service water heating from a district utility (steam, heating

hot water).

C404.3 Efficient heated water supply piping. Heated water supply piping shall be in accordance with Section

C404.3.1 or C404.3.2. The flow rate through 1/4-inch (6.4 mm) piping shall be not greater than 0.5 gpm (1.9

L/m). The flow rate through 5/16-inch (7.9 mm) piping shall be not greater than 1 gpm (3.8 L/m). The flow rate

through 3/8-inch (9.5 mm) piping shall be not greater than 1.5 gpm (5.7 L/m). Water heaters, circulating water

systems and heat trace temperature maintenance systems shall be considered sources of heated water.

C404.3.1 Maximum allowable pipe length method. The maximum allowable piping length from the nearest

source of heated water to the termination of the fixture supply pipe shall be in accordance with the following.

Where the piping contains more than one size of pipe, the largest size of pipe within the piping shall be used

for determining the maximum allowable length of the piping in Table C404.3.1.

1. For a public lavatory faucet, use the "Public lavatory faucets" column in Table C404.3.1.

2. For all other plumbing fixtures and plumbing appliances, use the "Other fixtures and appliances" column

in Table C404.3.1.

TABLE C404.3.1

PIPING VOLUME AND MAXIMUM PIPING LENGTHS

NOMINAL PIPE SIZE

(inches)

VOLUME

(liquid ounces per foot

length)

MAXIMUM PIPING LENGTH

(feet)

Public lavatory faucets

Other fixtures and

appliances

1/4

0.33

5/16

0.5

3/8

0.75

1/2

1.5

5/8

3/4

0.5

7/8

0.5

11/4

0.5

11/2

0.5

2 or larger

0.5

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C404.3.2 Maximum allowable pipe volume method. The water volume in the piping shall be calculated in

accordance with Section C404.3.2.1. The volume from the nearest source of heated water to the termination

of the fixture supply pipe shall be as follows:

1. For a public lavatory faucet: Not more than 2 ounces (0.06 L).

2. For other plumbing fixtures or plumbing appliances; not more than 0.5 gallon (1.89 L).

C404.3.2.1 Water volume determination. The volume shall be the sum of the internal volumes of pipe,

fittings, valves, meters and manifolds between the nearest source of heated water and the termination of the

fixture supply pipe. The volume in the piping shall be determined from the "Volume" column in Table

C404.3.1. The volume contained within fixture shutoff valves, within flexible water supply connectors to a

fixture fitting and within a fixture fitting shall not be included in the water volume determination. Where

heated water is supplied by a recirculating system or heat-traced piping, the volume shall include the portion

of the fitting on the branch pipe that supplies water to the fixture.

C404.4 Heat traps for hot water storage tanks. Storage tank-type water heaters and hot water storage tanks

that have vertical water pipes connecting to the inlet and outlet of the tank shall be provided with integral heat

traps at those inlets and outlets or shall have pipe-configured heat traps in the piping connected to those inlets

and outlets. Tank inlets and outlets associated with solar water heating system circulation loops shall not be

required to have heat traps.

C404.5 Water heater installation. Electric water heaters in unconditioned spaces or on concrete floors shall be

placed on an incompressible, insulated surface with a minimum thermal resistance of R-10.

C404.6 Insulation of piping. Piping from a water heater to the termination of the heated water fixture supply

pipe shall be insulated in accordance with Table C403.10.3. On both the inlet and outlet piping of a storage hot

water heater or heated water storage tank, the piping to a heat trap or the first 8 feet (2438 mm) of piping,

whichever is less, shall be insulated. Piping that is heat traced shall be insulated in accordance with Table

C403.10.3 or the heat trace manufacturer’s instructions. Tubular pipe insulation shall be installed in accordance

with the insulation manufacturer’s instructions. Pipe insulation shall be continuous, including through hangers

and supports, such that thermal bridging is prevented, except where the piping passes through a framing

member. The minimum insulation thickness requirements of this section shall not supersede any greater

insulation thickness requirements necessary for the protection of piping from freezing temperatures or the

protection of personnel against external surface temperatures on the insulation.

Exception: Tubular pipe insulation shall not be required on the following:

1. The tubing from the connection at the termination of the fixture supply piping to a plumbing fixture or

plumbing appliance.

2. Valves, pumps, strainers and threaded unions in piping that is 1 inch (25 mm) or less in nominal

diameter.

3. Piping from user-controlled shower and bath mixing valves to the water outlets.

4. Cold-water piping of a demand recirculation water system.

5. Tubing from a hot drinking-water heating unit to the water outlet.

6. Piping at locations where a vertical support of the piping is installed.

7. Piping surrounded by building insulation with a thermal resistance (R-value) of not less than R-3.

8. Hot water piping that is part of the final pipe run to the plumbing fixture and is not part of the heated-

water circulation system circulation path is not required to meet the minimum insulation requirements of

Section C404.6.

C404.7 Heated-water circulating and temperature maintenance systems. Heated-water circulation systems

shall be in accordance with Section C404.7.1. Heat trace temperature maintenance systems shall be in

accordance with Section C404.7.2. Controls for hot water storage shall be in accordance with Section C404.7.3.

Automatic controls, temperature sensors and pumps shall be in a location with access. Manual controls shall be

in a location with ready access.

C404.7.1 Circulation systems. Heated-water circulation systems shall be provided with a circulation pump.

The system return pipe shall be a dedicated return pipe. Gravity and thermo-syphon circulation systems shall

be prohibited. Controls shall start the pump based on the identification of a demand for hot water within the

occupancy.

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C404.7.1.1 Single riser systems. Where the circulation system serves only a single domestic hot water

riser or zone, the following controls shall be provided:

1. Control to automatically turn off the pump when the water in the circulation loop is at the supply

temperature and shall not turn the pump back on until the temperature is a minimum of 10°F lower

than the supply temperature or have controls equipped with automatic time switches or other controls

that can be set to switch off the pump during unoccupied hours when hot water is not required.

2. Control shall be equipped with manual switch or other controls that can be used to turn off the pump

during extended periods when hot water is not required.

C404.7.1.2 Multiple riser systems. Where the circulation system serves multiple domestic hot water risers

or piping zones, controls shall be provided such that they can be set to switch off the pump during extended

periods when hot water is not required. System shall include means for balancing the flow rate through each

individual hot water supply riser or piping zone.

C404.7.2 Heat trace systems. Electric heat trace systems shall comply with IEEE 515.1. Controls for such

systems shall be able to automatically adjust the energy input to the heat tracing to maintain the desired water

temperature in the piping in accordance with the times when heated water is used in the occupancy. Heat

trace shall be arranged to be turned off automatically when there is no hot water demand.

C404.7.3 Controls for hot water storage. The controls on pumps that circulate water between a water

heater and a heated-water storage tank shall limit operation of the pump from heating cycle startup to not

greater than 5 minutes after the end of the cycle.

C404.8 Demand recirculation controls. Demand recirculation water systems shall have controls that comply

with both of the following:

1. The controls shall start the pump upon receiving a signal from the action of a user of a fixture or

appliance, sensing the presence of a user of a fixture or sensing the flow of hot or tempered water to a

fixture fitting or appliance.

2. The controls shall limit the temperature of the water entering the cold water-piping to not greater than

104°F (40°C)

C404.9 Domestic hot water meters. Each individual dwelling unit in a Group R-2 occupancy with central

service domestic hot water systems shall be provided with a domestic hot water meter to allow for domestic hot

water billing based on actual domestic hot water usage.

Exception: Dwelling units in other than Group R-2 multi-family and live/work units are not required to provide

domestic hot water metering at each dwelling unit where domestic hot water is metered separately for each of

the following building end uses:

1. Dwelling units.

2. Sleeping units.

3. Commercial kitchens.

4. Central laundries.

C404.10 Drain water heat recovery units. Drain water heat recovery units shall comply with CSA B55.2.

Potable water-side pressure loss shall be less than 10 psi (69 kPa) at maximum design flow. For Group R

occupancies, the efficiency of drain water heat recovery unit efficiency shall be in accordance with CSA B55.1.

C404.11 Energy consumption of pools and permanent spas. The energy consumption of pools and

permanent spas shall be controlled by the requirements in Sections C404.11.1 through C404.11.4.

C404.11.1 Heaters. Heat pump pool heaters shall have a minimum COP of 4.0 determined in accordance

with ASHRAE Standard 146. Other pool heating equipment shall comply with the applicable efficiencies in

Section C404.2.

The electric power to all heaters shall be controlled by an on-off switch that is an integral part of the heater,

mounted on the exterior of the heater, or external to and within 3 feet of the heater in a location with ready

access. Operation of such switch shall not change the setting of the heater thermostat. Such switches shall be

in addition to a circuit breaker for the power to the heater. Gas fired heaters shall not be equipped with

constant burning pilot lights.

2018 Washington State Energy Code CE-95

C404.11.2 Time switches. Time switches or other control method that can automatically turn off and on

heaters and pump motors according to a preset schedule shall be installed for heaters and pump motors.

Heaters and pump motors that have built in time switches shall be in compliance with this section.

Exceptions:

1. Where public health standards require 24-hour pump operation.

2. Pumps that are required to operate solar- and waste-heat-recovery pool heating systems.

C404.11.3 Covers. Heated pools and in-ground permanent spas shall be provided with a vapor-retardant

cover on or at the water surface. Pools heated to more than 90°F shall have a pool cover with a minimum

insulation value of R-12, and the sides and bottom of the pool shall also have a minimum insulation value of

R-12.

C404.11.4 Heat recovery. Heated indoor swimming pools, spas or hot tubs with water surface area greater

than 200 square feet shall provide for energy conservation by an exhaust air heat recovery system that heats

ventilation air, pool water or domestic hot water. The heat recovery system shall be configured to decrease

the exhaust air temperature at design heating conditions (80°F indoor) by 36°F (10°C).

Exception: Pools, spas or hot tubs that include system(s) that provide equivalent recovered energy on an

annual basis through one of the following methods:

1. Solar water heating systems not claimed in Section C406.5 or Section C407;

2. Dehumidification heat recovery;

3. Waste heat recovery; or

4. A combination of these system sources capable of and configured to provide at least 70 percent of the

heating energy required over an operating season.

C404.12 Energy consumption of portable spas. The energy consumption of electric-powered portable spas

shall be controlled by the requirements of APSP 14.

C404.13 Service water pressure-booster systems. Service water pressure-booster systems shall be

designed and configured such that the following apply:

1. One or more pressure sensors shall be used to vary pump speed and/or start and stop pumps. The

sensors shall either be located near the critical fixtures that determine the pressure required, or logic shall

be employed that adjusts the set point to simulate operations of remote sensors.

2. No devices shall be installed for the purpose of reducing the pressure of all of the water supplied by any

booster system pump or booster system, except for safety devices.

3. Booster system pumps shall not operate when there is no service water flow except to refill hydro

pneumatic tanks.

4. Systems pump motors 7.5 hp and greater shall be provided with variable flow capacity in accordance with

Section C403.2.3.

C404.14 Commissioning. Service water heating systems shall be commissioned in accordance with Section

C408.

SECTION C405

ELECTRICAL POWER AND LIGHTING SYSTEMS

C405.1 General. This section covers lighting system controls, the maximum lighting power for interior and

exterior applications, electrical energy consumption, vertical and horizontal transportation systems, and

minimum efficiencies for motors and transformers.

Dwelling units within multi-family buildings shall comply with Sections C405.1.1 and C405.7. All other dwelling

units in dormitory, hotel and other residential occupancies that are not classified as multi-family residential

occupancies shall comply with Section C405.2.5 and Section C405.1.1 or Section C405.4. Sleeping units shall

comply with Section C405.2.5 and Section C405.1.1 or Section C405.4.

Lighting installed in walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated

warehouse freezers shall comply with the lighting requirements of Section C410.2.

Transformers, uninterruptable power supplies, motors and electrical power processing equipment in data

center systems shall comply with Section 8 of ASHRAE Standard 90.4 in addition to this code.

CE-96 2018 Washington State Energy Code

C405.1.1 Dwelling and sleeping unit lighting efficacy. No less than 90 percent of the lamps serving

dwelling units or sleeping units shall be provided by light emitting diodes (LED), T-8 or smaller diameter linear

fluorescent lamps, or other lamps with a minimum efficacy of 65 lumens per watt.

C405.2 Lighting controls. Lighting systems shall be provided with controls that comply with one of the

following:

1. Lighting controls as specified in Sections C405.2.1 through C405.2.7.

2. Luminaire level lighting controls (LLLC) and lighting controls as specified in Sections C405.2.1, C405.2.3

and C405.2.5. The LLLC luminaire shall be independently configured to:

2.1. Monitor occupant activity to brighten or dim lighting when occupied or unoccupied, respectively.

2.2. Monitor ambient light, both electric and daylight, and brighten or dim artificial light to maintain desired

light level.

2.3. For each control strategy, configuration and re-configuration of performance parameters including:

bright and dim set points, timeouts, dimming fade rates, sensor sensitivity adjustments, and wireless

zoning configuration.

Exception: Except for specific application controls required by Section C405.2.5, lighting controls are not

required for the following:

1. Areas designated as security or emergency areas that are required to be continuously lighted.

2. Means of egress illumination serving the exit access that does not exceed 0.02 watts per square foot of

building area is exempt from this requirement..

3. Emergency egress lighting that is normally off.

4. Industrial or manufacturing process areas, as may be required for production and safety.

C405.2.1 Occupant sensor controls. Occupant sensor controls shall be installed to control lights in the

following space types:

1. Classrooms/lecture/training rooms.

2. Conference/meeting/multipurpose rooms.

3. Copy/print rooms.

4. Lounge/breakrooms.

5. Enclosed offices.

6. Open plan office areas.

7. Restrooms.

8. Storage rooms.

9. Locker rooms.

10. Other spaces 300 square feet (28 m

) or less that are enclosed by floor-to- ceiling height partitions.

11. Warehouse storage areas.

12. Enclosed fire rated stairways.

13. Service corridors.

14. Covered parking areas.

Occupant sensor controls in warehouse storage areas, stairways, corridors and library stacks shall comply

with Section C405.2.1.2. Occupant sensor controls in open plan office areas shall comply with Section

C405.2.1.3. Occupant sensor controls in covered parking areas shall comply with Section C405.2.1.4.

Occupant sensors in fire rated stairways shall comply with Section C405.2.1.5. Occupant sensor controls for

all other spaces shall comply with Section C405.2.1.1.

Exceptions:

1. Corridors in manufacturing facilities.

2. General lighting and task lighting in shop and laboratory classrooms.

3. Digital timer switch controls may be provided in lieu of occupant sensor controls in the following space

types if under 300 square feet: copy/print rooms, storage rooms and janitorial closets.

Digital timer switches shall comply with the following:

3.1. Turn lights on or off with operation of a button, switch or other manual means.

3.2. Automatically turn lights off within 15 minutes of the lights being turned on. The means for setting

the time delay shall not be visible on the front of the switch.

3.3. The switch shall provide both audible and visual indication of impending time-out of the switch.

Audible and visual indication shall be given at least once within five minutes of time-out of the

switch. Visual indication shall consist of turning the lights momentarily off, and then back on.

2018 Washington State Energy Code CE-97

C405.2.1.1 Occupant sensor control function. Occupant sensor controls shall comply with all of the

following:

1. They shall be configured to automatically turn off lights within 20 minutes of all occupants leaving the

space.

2. They shall be manual on or shall be configured to automatically turn the lighting on to not more than

50 percent power.

Exception: Full automatic-on controls shall be permitted to control lighting in public corridors,

stairways, restrooms, primary building entrance areas and lobbies, and areas where manual-on

operation would endanger the safety or security of the room or building occupants.

3. They shall incorporate a manual control to allow occupants to turn lights off.

C405.2.1.2 Occupant sensor control function in warehouses, storage areas and service corridors.

Occupant sensor controls shall be configured to comply with all of the following:

1. Automatically reduce lighting power by not less than 50 percent within 20 minutes of all occupants

leaving the area.

2. Control lighting in each aisleway and corridor independently, and shall not control lighting beyond the

aisleway or corridor being controlled by the sensor.

3. Automatically turn lighting off within 20 minutes of all occupants leaving the space, or comply with

Section C405.2.2 to turn lighting off when the building is vacant.

4. Restore lighting to full power when occupants enter the space.

C405.2.1.3 Occupant sensor control function in open plan office areas. Occupant sensor controls in

open plan office spaces less than 300 square feet (28 m

) in area shall comply with Section C405.2.1.1.

Occupant sensor controls in all other open plan office spaces shall be configured to comply with all of the

following:

1. General lighting is controlled separately in control zones with floor areas not greater than 600 square

feet (55 m

) within the open plan office space.

2. Automatically turn off general lighting in all control zones within 20 minutes after all occupants have left

the open plan office space.

3. General lighting power in each control zone is reduced by not less than 80 percent of the full zone

general lighting power within 20 minutes of all occupants leaving that control zone. Control functions

that switch control zone lights completely off when the zone is unoccupied meet this requirement.

4. Daylight responsive controls activate open plan office space general lighting or control zone general

lighting only when occupancy for the same area is detected.

C405.2.1.4 Occupant sensor control function in parking garages. Occupant sensor controls shall be

configured to comply with all of the following:

1. Lighting power of each luminaire shall be automatically reduced by a minimum of 30 percent when

there is no vehicle or pedestrian activity detected within a lighting zone for 20 minutes. Lighting zones

for this requirement shall be no larger than 3600 square feet.

Exceptions:

4.1 Lighting in daylight transition zones and ramps without parking.

4.2 Covered parking garages with a total lighting power less than 0.07 watts per square foot.

2. Where time switch controls in accordance with Section C405.2.2 are not installed, the occupant

sensor shall automatically turn all the lighting off within 20 minutes of all occupants leaving the space

and restore lighting to full power when occupants enter the space.

C405.2.1.5 Occupant sensor control function in enclosed fire rated stairways. Occupant sensor

controls shall be configured to automatically reduce lighting power by not less than 50 percent when no

occupants have been detected in the stairway for a period not exceeding 20 minutes and restore lighting to

full power when occupants enter the stairway. All portions of stairways shall remain illuminated to meet the

requirements of Section 1009 of the International Building Code when the lighting power is reduced.

C405.2.2 Time switch controls. Each area of the building that is not provided with occupant sensor controls

or digital timer switch controls complying with Section C405.2.1 shall be provided with time switch controls

complying with Section C405.2.2.1.

Exception: Where a manual control provides light reduction in accordance with Section C405.2.3.1, time-

switch controls shall not be required for the following:

CE-98 2018 Washington State Energy Code

1. Spaces where patient care is directly provided.

2. Spaces where an automatic shutoff would endanger occupant safety or security.

3. Lighting intended for continuous operation.

4. Shop and laboratory classrooms.

C405.2.2.1 Time switch control function. Time switch controls shall comply with the following:

1. Have a minimum 7 day clock.

2. Be capable of being set for 7 different day types per week.

3. Incorporate an automatic holiday "shut-off" feature, which turns off all controlled loads for at least 24

hours and then resumes normally scheduled operations.

4. Have program back-up capabilities, which prevent the loss of program and time settings for at least 10

hours, if power is interrupted.

5. Include an override switching device that complies with the following:

5.1 The override switch shall be a manual control.

5.2 The override switch, when initiated, shall permit the controlled lighting to remain on for not more

than 2 hours.

5.3 Any individual override switch shall control the lighting for an area not larger than 5,000 square

feet (465 m

6. Time switch controls are allowed to automatically turn on lighting to full power in corridors, lobbies,

restrooms, storage rooms less than 50 square feet, and medical areas of healthcare facilities. In all

other spaces, time switch controls are allowed to automatically turn on the lighting to not more than 50

percent power.

Exception: Within mall concourses, auditoriums, sales areas, manufacturing facilities and sports arenas:

1.1. The time limit shall be permitted to be greater than 2 hours provided the switch is a captive

key device.

1.2. The area controlled by the override switch shall not be limited to 5,000 square feet (465 m

)

provided that such area is less than 20,000 square feet (1860 m

C405.2.3 Manual controls. All lighting shall have manual controls complying with the following:

1. They shall be in a location with ready access to occupants.

2. They shall be located where the controlled lights are visible, or shall identify the area served by the

lights and indicate their status.

3. Each control device shall control an area no larger than a single room or 2,500 square feet, whichever is

less, if the room area is less than or equal to 10,000 square feet; or one-quarter of the room or 10,000

square feet, whichever is less, if the room area is greater than 10,000 square feet.

Exceptions:

1. A manual control may be installed in a remote location for the purpose of safety or security provided

each remote control device has an indicator pilot light as part of or next to the control device and the

light is clearly labeled to identify the controlled lighting.

2. Restrooms.

C405.2.3.1 Light reduction controls. Manual controls shall be configured to provide light reduction control

that allows the occupant to reduce the connected lighting load between 30 and 70 percent. Lighting

reduction shall be achieved by one of the following approved methods:

1. Controlling all lamps or luminaires.

2. Dual switching of alternate rows of luminaires, alternate luminaires or alternate lamps.

3. Switching the middle lamp luminaires independently of the outer lamps.

4. Switching each luminaire or each lamp.

Exceptions:

1. Light reduction controls are not required in daylight zones with daylight responsive controls

complying with Section C405.2.4.

2. Where provided with manual control, the following areas are not required to have light reduction

control:

2.1. Spaces that have only one luminaire with a rated power of less than 100 watts.

2018 Washington State Energy Code CE-99

◄

2.2. Spaces that use less than 0.6 watts per square foot (6.5 W/m

2.3. Lighting in corridors, lobbies, electrical rooms, restrooms, storage rooms, airport concourse

baggage areas, dwelling and sleeping rooms and mechanical rooms.

C405.2.4 Daylight responsive controls. Daylight responsive controls complying with Section C405.2.4.1

shall be provided to control the lighting within daylight zones in the following spaces:

1. Sidelit zones as defined in Section C405.2.4.2 with more than two general lighting fixtures within the

combined primary and secondary sidelit zones.

2. Toplit zones as defined in Section C405.2.4.3 with more than two general lighting fixtures within the

daylight zone.

Exception: Daylight responsive controls are not required for the following:

1. Spaces in health care facilities where patient care is directly provided.

2. Lighting that is required to have specific application control in accordance with Section C405.2.5.

3. Sidelit zones on the first floor above grade in Group A-2 and Group M occupancies.

4. Daylight zones where the total proposed lighting power density is less than 35 percent of the lighting

power allowance per Section C405.4.2.

C405.2.4.1 Daylight responsive controls function. Where required, daylight responsive controls shall be

provided within each space for control of lights in that space and shall comply with all of the following:

1. Lights in primary sidelit t zones shall be controlled independently of lights in secondary sidelit zones in

accordance with Section C405.2.4.2.

Exception: Spaces enclosed by walls or ceiling height partitions with no more than three general

lighting fixtures may have combined daylight zone control of primary and secondary daylight zones

provided uniform illumination can be achieved.

2. Lights in toplit zones in accordance with Section C405.2.4.3 shall be controlled independently of lights in

sidelit zones in accordance with Section C405.2.4.2.

3. Daylight responsive controls within each space shall be configured so that they can be calibrated from

within that space by authorized personnel.

4. Calibration mechanisms shall be in a location with ready access.

5. Daylight responsive controls shall be configured to completely shut off all controlled lights in that zone.

6. Lights in sidelit zones in accordance with Section C405.2.4.2 facing different cardinal orientations (i.e.,

within 45 degrees of due north, east, south, west) shall be controlled independently of each other.

Exception: Up to two light fixtures in each space are permitted to be controlled together with lighting

in a daylight zone facing a different cardinal orientation.

7. Incorporate time-delay circuits to prevent cycling of light level changes of less than three minutes.

8. The maximum area a single daylight responsive control device serves shall not exceed 2,500 square

feet (232 m

9. Occupant override capability of daylight dimming controls is not permitted, other than a reduction of light

output from the level established by the daylighting controls.

C405.2.4.1.1 Dimming. Daylight responsive controls shall be configured to automatically reduce the

power of general lighting in the daylight zone in response to available daylight, while maintaining uniform

illumination in the space through one of the following methods:

1. Continuous dimming using dimming ballasts/dimming drivers and daylight-sensing automatic controls.

The system shall reduce lighting power continuously to less than 15 percent of rated power at

maximum light output.

2. Stepped dimming using multi-level switching and daylight-sensing controls. The system shall provide

a minimum of two steps of uniform illumination between 0 and 100 percent of rated power at

maximum light output. Each step shall be in equal increments of power, plus or minus 10 percent.

General lighting within daylight zones in offices, classrooms, laboratories and library reading rooms shall

use the continuous dimming method. Stepped dimming is not allowed as a method of daylight zone

control in these spaces.

CE-100 2018 Washington State Energy Code

C405.2.4.2 Sidelit zone. The sidelit zone is the floor area adjacent to vertical fenestration which complies

with the following:

1. Where the fenestration is located in a wall, the sidelit zone includes the primary and secondary

daylight zones. The primary daylight zone shall extend laterally to the nearest full height wall, or up to

1.0 times the height from the floor to the top of the fenestration, and longitudinally from the edge of the

fenestration to the nearest full height wall, or up to 2 feet (610 mm), whichever is less, as indicated in

Figure C405.2.4.2(1). The secondary daylight zone begins at the edge of the primary daylight zone

and extends laterally to the nearest full height wall, or up to 2.0 times the height from the floor to the

top of the fenestration, whichever is less, as indicated in Figure C405.2.4.2(1).

2. Where clerestory fenestration is located in a wall, the sidelit zone includes a lateral area twice the

depth of the clerestory fenestration height, projected upon the floor at a 45 degree angle from the

center of the clerestory fenestration. The longitudinal width of the sidelit zone is calculated the same

as for fenestration located in a wall. Where the 45 degree angle is interrupted by an obstruction

greater than 0.7 times the ceiling height, the daylight zone shall remain the same lateral area but be

located between the clerestory and the obstruction, as indicated in Figure C405.2.4.2(2).

3. If the rough opening area of a vertical fenestration assembly is less than 10 percent of the calculated

primary sidelit zone area for this fenestration, it does not qualify as a sidelit zone.

4. The visible transmittance of the fenestration is no less than 0.20.

5. In parking garages with floor area adjacent to perimeter wall openings, the sidelit zone shall include

the area within 20 feet of any portion of a perimeter wall that has a net opening to wall ratio of at least

40 percent.

C405.2.4.3 Toplit zone. The toplit zone is the floor area underneath a roof fenestration assembly which

complies with the following:

1. The toplit zone shall extend laterally and longitudinally beyond the edge of the roof fenestration

assembly to the nearest obstruction that is taller than 0.7 times the ceiling height, or up to 0.7 times

the ceiling height, whichever is less, as indicated in Figure C405.2.4.3(1).

2. Where the fenestration is located in a rooftop monitor, the toplit zone shall extend laterally to the

nearest obstruction that is taller than 0.7 times the ceiling height, or up to 1.0 times the height from the

floor to the bottom of the fenestration, whichever is less, and longitudinally from the edge of the

fenestration to the nearest obstruction that is taller than 0.7 times the ceiling height, or up to 0.25

times the height from the floor to the bottom of the fenestration, whichever is less, as indicated in

Figures C405.2.4.3(2) and C405.2.4.3(3).

3. Where toplit zones overlap with sidelit zones, lights within the overlapping area shall be assigned to

the toplit zone.

4. The product of the visible transmittance of the roof fenestration assembly and the area of the rough

opening of the roof fenestration assembly, divided by the area of the toplit zone is no less than 0.008.

5. Where located under atrium fenestration, the toplit zone shall include the bottom floor area directly

beneath the atrium fenestration, and the top floor directly under the atrium fenestration, as indicated in

Figure C405.2.4.3(4). The toplit zone area at the top floor is calculated the same as for a toplit zone.

Intermediate levels below the top floor that are not directly beneath the atrium are not included.

2018 Washington State Energy Code CE-101

FIGURE C405.2.4.2(1)

SIDELIT ZONE ADJACENT TO FENESTRATION IN A WALL

FIGURE C405.2.4.2(2)

SIDELIT ZONE ADJACENT TO CLERESTORY FENESTRATION IN A WALL

CE-102 2018 Washington State Energy Code

FIGURE C405.2.4.3(1)

TOPLIT ZONE UNDER A ROOFTOP FENESTRATION ASSEMBLY

2018 Washington State Energy Code CE-103

FIGURE C405.2.4.3(2)

TOPLIT ZONE UNDER A ROOFTOP MONITOR

FIGURE C405.2.4.3(3)

TOPLIT ZONE UNDER A SLOPED ROOFTOP MONITOR

FIGURE C405.2.4.3(4)

TOPLIT ZONE UNDER ATRIUM FENESTRATION

CE-104 2018 Washington State Energy Code

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C405.2.5 Additional lighting controls. Specific application lighting shall be provided with controls, in addition

to controls required by other sections, for the following:

1. The following lighting shall be controlled by an occupant sensor complying with Section C405.2.1.1 or a

time-switch control complying with Section C405.2.2.1 In addition, a manual control shall be provided to

control such lighting separately from the general lighting in the space:

1.1. Display and accent.

1.2. Lighting in display cases.

1.3. Supplemental task lighting, including permanently installed under-shelf or under-cabinet lighting.

1.4. Lighting equipment that is for sale or demonstration in lighting education.

2. Sleeping units shall have control devices or systems configured to automatically switch off all permanently

installed luminaires and switched receptacles within 20 minutes after all occupants have left the unit.

Exceptions: 1.Lighting and switched receptacles controlled by card key controls.

2. Spaces where patient care is directly provided.

3. Permanently installed luminaires within dwelling units shall be provided with controls complying with either

Section C405.2.1.1 or C405.2.3.1.

4. Lighting for nonvisual applications, such as plant growth and food warming, shall be controlled by a

dedicated control that is independent of the controls for other lighting within the room or space. Each

control zone shall be no greater than the area served by a single luminaire or 4,000 square feet,

whichever is larger.

5. Luminaires serving the exit access and providing means of egress illumination required by Section 1006.1

of the International Building Code, including luminaires that function as both normal and emergency

means of egress illumination shall be controlled by a combination of listed emergency relay and

occupancy sensors, or signal from another building control system, that automatically shuts off the lighting

when the areas served by that illumination are unoccupied.

Exception: Means of egress illumination serving the exit access that does not exceed 0.02 watts per

square foot of building area is exempt from this requirement.

C405.2.6 Exterior lighting controls. Exterior lighting systems shall be provided with controls that comply with

Sections C405.2.6.1 through C405.2.6.4. Decorative lighting systems shall comply with Sections C405.2.6.1,

C405.2.6.2 and C405.2.6.4.

Exceptions:

1. Lighting for covered vehicle entrances or exits from buildings or parking structures where required for

safety, security or eye adaption.

2. Lighting controlled from within dwelling units.

C405.2.6.1 Daylight shutoff. Lights shall be configured to automatically turn off when daylight is present

and satisfies the lighting needs.

C405.2.6.2 Facade and landscape lighting shutoff. Building façade and landscape lighting shall be

configured to automatically shut off for a minimum of 6 hours per night or from not later than one hour after

business closing to not earlier than one hour before business opening, whichever is less.

Exception: Areas where an automatic shutoff would endanger safety or security.

C405.2.6.3 Lighting setback. Lighting that is not controlled in accordance with Section C405.2.6.2 shall be

controlled so that the total wattage of such lighting is automatically reduced by not less than 30 percent by

selectively switching off or dimming luminaires at one of the following times:

1. From not later than 12 midnight to 6 a.m.

2. From not later than one hour after business closing to not earlier than one hour before business

opening.

3. During any period when no activity has been detected for 15 minutes or more.

C405.2.6.4 Exterior time-switch control functions. Time switch controls for exterior lighting shall comply

with the following:

1. They shall have a clock capable of being programmed for not fewer than 7 days.

2. They shall be capable of being set for seven different day types per week.

2018 Washington State Energy Code CE-105

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3. They shall incorporate an automatic holiday setback feature.

4. They shall have program backup capabilities that prevent the loss of program and time settings for a

period of at least 10 hours in the event that power is interrupted.

C405.2.7 Area controls. The maximum lighting power that may be controlled from a single switch or

automatic control device shall not exceed that which is provided by a 20 ampere circuit loaded to not more

than 80 percent. A master control may be installed provided the individual switches retain their capability to

function independently. Circuit breakers may not be used as the sole means of switching.

Exception: Areas less than 5 percent of the building footprint for footprints over 100,000 ft

C405.3 Reserved

C405.4 Interior lighting power requirements. A building complies with this section if its total connected interior

lighting power calculated under Section C405.4.1 is no greater than the interior lighting power allowance

calculated under Section C405.4.2.

C405.4.1 Total connected interior lighting power. The total connected interior lighting power shall be

determined in accordance with Equation 4-10.

(Equation 4-10)

TCLP = [LVL + BLL + TRK+ POE + Other]

Where:

TCLP

Total connected lighting power (watts)

LVL

For luminaires with lamps connected directly to building power, such

as line voltage lamps, the rated wattage of the lamp, which must be

minimum 60 lumen/watt.

BLL

For luminaires incorporating a ballast or transformer, the rated input

wattage of the ballast or transformer when operating the lamp.

TRK

For lighting track, cable conductor, rail conductor and plug-in busway

systems that allow the addition and relocation of luminaires without

rewiring, the wattage shall be one of the following:

1. The specified wattage of the luminaires, but not less than 16

W/lin. ft. (52 W/lin. m).

2. The wattage limit of the permanent current-limiting devices

protecting the system.

3. The wattage limit of the transformer supplying the system.

POE

For other modular lighting systems served with power supplied by a

driver, power supply or transformer, including but not limited to low-

voltage lighting systems, the wattage of the system shall be the

maximum rated input wattage of the driver, power supply or

transformer published in the manufacturer’s catalogs, as specified by

UL 2108 or 8750. For power-over-Ethernet lighting systems, power

provided to installed non-lighting devices may be subtracted from the

total power rating of the power-over-Ethernet system.

Other

The wattage of all other luminaires and lighting, sources not covered

above and associated with interior lighting verified by data supplied

by the manufacturer or other approved sources.

The connected power associated with the following lighting equipment and applications is not included in

calculating total connected lighting power

1. Television broadcast lighting for playing areas in sports arenas

2. Emergency lighting automatically off during normal building operation.

3. Lighting in spaces specifically designed for use by occupants with special lighting needs including

those with visual impairment and other medical and age-related issues.

4. Casino gaming areas.

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5. General area lighting power in industrial and manufacturing occupancies dedicated to the inspection or

quality control of goods and products.

6. Mirror lighting in dressing rooms.

7. Task lighting for medical and dental purposes that is in addition to general lighting and controlled by an

independent control device.

8. Display lighting for exhibits in galleries, museums and monuments that is in addition to general lighting

and controlled by an independent control device.

9. Lighting for theatrical purposes, including performance, stage, film production and video production.

10. Lighting for photographic processes.

11. Lighting integral to equipment or instrumentation and installed by the manufacturer.

12. Task lighting for plant growth or maintenance where the lamp efficacy is not less than 90 lumens per

watt.

13. Advertising signage or directional signage.

14. Lighting for food warming.

15. Lighting equipment that is for sale.

16. Lighting demonstration equipment in lighting education facilities.

17. Lighting approved because of safety considerations.

18. Lighting in retail display windows, provided the display area is enclosed by ceiling-height partitions.

19. Furniture mounted supplemental task lighting that is controlled by automatic shutoff.

20. Exit signs.

21. Lighting used for aircraft painting.

C405.4.2 Interior lighting power allowance. The total interior lighting power allowance (watts) is determined

according to Table C405.4.2(1) using the Building Area Method, or Table C405.4.2(2) using the Space-by-

Space Method, for all areas of the building covered in this permit.

C405.4.2.1 Building area method. For the Building Area Method, the interior lighting power allowance is

the floor area for each building area type listed in Table C405.4.2(1) times the value from Table C405.4.2(1)

for that area. For the purposes of this method, an "area" shall be defined as all contiguous spaces that

accommodate or are associated with a single building area type as listed in Table C405.4.2(1). Where this

method is used to calculate the total interior lighting power for an entire building, each building area type

shall be treated as a separate area.

C405.4.2.2 Space-by-space method. For the Space-by-Space Method, the interior lighting power

allowance is determined by multiplying the floor area of each space times the value for the space type in

Table C405.4.2(2) that most closely represents the proposed use of the space, and then summing the

lighting power allowances for all spaces. Tradeoffs among spaces are permitted.

Each area enclosed by partitions that are 80 percent of the ceiling height or taller shall be considered a

separate space and assigned the appropriate space type from Table C405.4.2(2). If a space has multiple

functions where more than one space type is applicable, that space shall be broken up into smaller

subspaces, each using their own space type. Any of these subspaces that are smaller in floor area than 20

percent of the enclosed space and less than 1,000 square feet need not be broken out separately.

2018 Washington State Energy Code CE-107

TABLE C405.4.2(1)

INTERIOR LIGHTING POWER ALLOWANCES: BUILDING AREA METHOD

Building Area Type

LPD (w/ft

)

Automotive facility

0.64

Convention center

0.64

Court house

0.79

Dining: Bar lounge/leisure

0.79

Dining: Cafeteria/fast food

0.72

Dining: Family

0.71

Dormitory

a,b

0.46

Exercise center

0.67

Fire station

0.54

Gymnasium

0.75

Health care clinic

0.70

Hospital

0.84

Hotel

a,b

0.56

Library

0.83

Manufacturing facility

0.82

Motion picture theater

0.44

Multifamily

0.41

Museum

0.55

Office

0.64

Parking garage

0.14

Penitentiary

0.65

Performing arts theater

0.84

Police station

0.66

Post office

0.65

Religious building

0.67

Retail

0.84

School/university

0.70

Sports arena

0.62

Town hall

0.69

Transportation

0.50

Warehouse

0.40

Workshop

0.91

a. Where sleeping units are excluded from lighting power calculations by application of Section R404.1, neither the area

of the sleeping units nor the wattage of lighting in the sleeping units is counted.

b. Where dwelling units are excluded from lighting power calculations by application of Section R404.1, neither the area

of the dwelling units nor the wattage of lighting in the dwelling units is counted.

c. Dwelling units are excluded. Neither the area of the dwelling units nor the wattage of lighting in the dwelling units is

counted.

CE-108 2018 Washington State Energy Code

TABLE C405.4.2(2)

INTERIOR LIGHTING POWER ALLOWANCES: SPACE-BY-SPACE METHOD

COMMON SPACE-BY-SPACE

TYPES

LPD (w/ft

)

Atrium - Less than 20 feet in height

0.39

Atrium – 20 to 40 feet in height

0.48

Atrium - Above 40 feet in height

0.60

Audience/seating area - Permanent

In an auditorium

0.61

In a gymnasium

0.23

In an motion picture theater

0.27

In a penitentiary

0.67

In an performing arts theater

1.16

In a religious building

0.72

In a sports arena

0.33

Otherwise

0.23

Banking activity area

0.61

Breakroom (see Lounge/breakroom)

Classroom/lecture hall/training room

In a penitentiary

0.89

Otherwise

0.71

Computer room, data center

0.94

Conference/meeting/multipurpose

0.97

Confinement cell

0.70

Copy/print room

0.31

Corridor

In a facility for the visually

impaired (and not used primarily

by the staff)

0.71

In a hospital

0.71

In a manufacturing facility

0.41

Otherwise

0.41

Courtroom

1.20

Dining area

In a penitentiary

0.42

In a facility for the visually

impaired (and not used primarily

by the staff)

1.27

In a bar/lounge or leisure dining

0.86

In cafeteria or fast food dining

0.40

In a family dining area

0.60

Otherwise

0.43

Electrical/mechanical

0.43

Emergency vehicle garage

0.52

Food preparation

1.09

COMMON SPACE-BY-SPACE

TYPES

LPD (w/ft

)

Guest room

a,b

0.41

Laboratory

In or as a classrooms

1.11

Otherwise

1.33

Laundry/washing area

0.53

Loading dock, interior

0.88

Lobby

In a facility for the visually

impaired (and not used primarily

by the staff)

1.69

For an elevator

0.65

In a hotel

0.51

In a motion picture theater

0.23

In a performing arts theater

1.25

Otherwise

0.84

Locker room

0.52

Lounge /breakroom

In a health care facility

0.42

Otherwise

0.59

Office

Enclosed ≤ 250

0.74

Enclosed >250

0.66

Open plan

0.61

Parking area, interior

0.15

Pharmacy area

1.66

Restroom

In a facility for the visually

impaired (and not used primarily

by the staff)

1.26

Otherwise

0.63

Sales area

1.05

Seating area, general

0.23

Stairway (See space containing

stairway)

Stairwell

0.49

Storage room

< 50 ft

0.51

50-100 ft

0.38

All other storage

0.38

Vehicular maintenance

0.60

Workshop

1.26

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TABLE C405.4.2(2) (continued)

INTERIOR LIGHTING POWER ALLOWANCES: SPACE-BY-SPACE METHOD

BUILDING SPECIFIC

SPACE-BY-SPACE TYPES

LPD (w/ft

)

Automotive

0.60

Convention center - Exhibit space

0.61

Dormitory living quarters

a,b

0.50

Facility for the visually impaired

In a chapel (and not used

primarily by the staff)

0.70

In a recreation room (and not

used primarily by the staff)

1.77

Fire stations

Sleeping quarters

0.23

Gymnasium/fitness center

In an exercise area

0.90

In a playing area

0.85

Health care facility

In an exam/treatment room

1.40

In an imaging room

0.94

In a medical supply room

0.62

In a nursery

0.92

In a nurse’s station

1.17

In an operating room

2.26

In a patient room

0.68

In a physical therapy room

0.91

In a recovery room

1.25

Library

In a reading area

0.31

In the stacks

1.10

Manufacturing facility

In a detailed manufacturing

area

0.80

In an equipment room

0.76

In an extra high bay area

(> 50-foot floor-ceiling height)

1.42

BUILDING SPECIFIC

SPACE-BY-SPACE TYPES

LPD (w/ft

)

In a high bay area

(25 - 50-foot floor-ceiling

height)

1.24

In a low bay area

(< 25-foot floor-ceiling height)

0.86

Museum

In a general exhibition area

0.31

In a restoration room

1.10

Performing arts theater

dressing/fitting room

0.41

Post office—Sorting area

0.71

Religious building

In a fellowship hall

0.54

In a worship pulpit/choir

area

0.85

Retail

In a dressing/fitting room

0.51

In a mall concourse

0.82

Sports arena—Playing area

For a Class 1 facility

2.94

For a Class 2 facility

2.01

For a Class 3 facility

1.30

For a Class 4 facility

0.86

Transportation

In a baggage/carousel area

0.39

In an airport concourse

0.25

At a terminal ticket counter

0.51

Warehouse—Storage area

For medium to bulky

palletized items

0.33

For smaller, hand-carried

items

0.69

For SI: 1 foot = 304.8 mm, 1 watt per square foot = 11 W/m

a. In cases where both a common space type and a building area specific space type are listed, the building area specific

space type shall apply.

b. A facility for the visually impaired is a facility that is licensed or will be licensed by local or state authorities for senior

long-term care, adult daycare, senior support or people with special visual needs.

c. For spaces in which lighting is specified to be installed in addition to, and controlled separately from, the general lighting

for the purposed of highlighting art or exhibits, provided that the additional lighting power shall not exceed 0.5 W/ft

such spaces.

d. RESERVED.

e. RESERVED.

f. RESERVED.

g. Where sleeping units are excluded from lighting power calculations by application of Section R404.1, neither the area of

the sleeping units nor the wattage of lighting in the sleeping units is counted.

h. Where dwelling units are excluded from lighting power calculations by application of Section R404.1, neither the area of

the dwelling units nor the wattage of lighting in the dwelling units is counted.

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i. Class I facilities consist of professional facilities; and semi-professional, collegiate or club facilities with seating for 5,000

or more spectators.

j. Class II facilities consist of collegiate and semi-professional facilities with seating for fewer than 5,000 spectators; club

facilities with seating between 2,000 and 5,000 spectators; and amateur league and high school facilities with seating for

more than 2,000 spectators.

k. Class III facilities consist of club, amateur league and high school facilities with seating for 2,000 or fewer spectators.

l. Class IV facilities consist of elementary school and recreational facilities; and amateur league and high school facilities

without provisions for spectators.

m. For classrooms, additional lighting power allowance of 4.50 W/lineal foot of white or chalk boards for directional lighting

dedicated to white or chalk boards.

n. Additional lighting power allowance of 0.30 W/square foot for ornamental lighting. Qualifying ornamental lighting

includes luminaires such as chandeliers, sconces, lanterns, neon and cold cathode, light emitting diodes, theatrical

projectors, moving lights and light color panels when any of those lights are used in a decorative manner that does not

serve as display lighting or general lighting.

C405.4.2.2.1 Additional interior lighting power. Where using the Space-by-Space Method, an increase

in the interior lighting power allowance is permitted for specific lighting functions. Additional power shall be

permitted only where the specified lighting is installed and automatically controlled separately from the

general lighting, to be turned off during nonbusiness hours. This additional power shall be used only for

the specified luminaires and shall not be used for any other purpose. An increase in the interior lighting

power allowance is permitted for lighting equipment to be installed in sales areas specifically to highlight

merchandise. The additional lighting power shall be determined in accordance with Equation 4-11:

Additional interior lighting power allowance = 500 watts + (Retail Area 1

0.45 W/ft

) + (Retail Area 2

0.45 W/ft

) + (Retail Area 3

1.05 W/ft

) + (Retail Area 4

1.87 W/ft

)

(Equation 4-11)

Where:

Retail Area 1

The floor area for all products not listed in

Retail Area 2, 3 or 4.

Retail Area 2

The floor area used for the sale of vehicles,

sporting goods and small electronics.

Retail Area 3

The floor area used for the sale of furniture,

clothing, cosmetics and artwork.

Retail Area 4

The floor area used for the sale of jewelry,

crystal and china.

Exception: Other merchandise categories are permitted to be included in Retail Areas 2 through 4,

provided that justification documenting the need for additional lighting power based on visual

inspection, contrast, or other critical display is approved by the code official.

C405.5 Exterior lighting power requirements. The total connected exterior lighting power calculated in

accordance with Section C405.5.2 shall not be greater than the exterior lighting power allowance calculated in

accordance with Section C405.5.3.

C405.5.1 Exterior building grounds lighting. All exterior building grounds luminaires that operate at greater

than 50 watts shall have a minimum efficacy of 100 lumens per watt unless the luminaire is controlled by a

motion sensor or qualifies for one of the exceptions under Section C405.5.2.

Exceptions:

1. Solar-powered lamps not connected to any electrical service.

2. Luminaires controlled by a motion sensor.

3. Luminaires that qualify for one of the exceptions under Section C405.5.2.

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C405.5.2 Total connected exterior building lighting power. The total exterior connected lighting power

shall be the total maximum rated wattage of all lighting that is powered through the energy service for the

building.

Exception: Lighting used for the following applications shall not be included:

1. Lighting approved because of safety considerations.

2. Emergency lighting automatically off during normal business operation.

3. Exit signs.

4. Specialized signal, directional and marker lighting associated with transportation.

5. Advertising signage or directional signage.

6. Integral to equipment or instrumentation and is installed by its manufacturer.

7. Theatrical purposes, including performance, stage, film production and video production.

8. Athletic playing areas.

9. Temporary lighting.

10. Industrial production, material handling, transportation sites and associated storage areas.

11. Theme elements in theme/amusement parks.

12. Lighting integrated within or used to highlight features of art, public monuments and the national flag.

13. Lighting for water features and swimming pools.

14. Lighting that is controlled from within dwelling units, where the lighting complies with Section R404.1.

C405.5.3 Exterior lighting power allowance. The total exterior lighting power allowance is the sum of the

base site allowance plus the individual allowances for areas that are to be illuminated by lighting that is

powered through the energy service for the building. Lighting power allowances are as specified in Table

C405.5.3(2). The lighting zone for the building exterior is determined in accordance with Table C405.5.3(1)

unless otherwise specified by the code official.

TABLE C405.5.3(1)

EXTERIOR LIGHTING ZONES

LIGHTING

ZONE

DESCRIPTION

Developed areas of national parks, state parks,

forest land, and rural areas

Areas predominantly consisting of residential

zoning, neighborhood business districts, light

industrial with limited nighttime use and residential

mixed use areas

All other areas not classified as lighting zone 1, 2 or

High-activity commercial districts in major

metropolitan areas as designated by the local land

use planning authority

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TABLE C405.5.3(2)

LIGHTING POWER ALLOWANCES FOR BUILDING EXTERIORS

LIGHTING ZONES

Zone 1

Zone 2

Zone 3

Zone 4

Base Site Allowance

350 W

400 W

500 W

900 W

Uncovered Parking Areas

Parking areas and drives

0.03 W/ft

0.04 W/ft

0.06 W/ft

0.08 W/ft

Building Grounds

Walkways and ramps less than 10 feet wide

0.5

W/linear

foot

0.5

W/linear

foot

0.6

W/linear

foot

0.7

W/linear

foot

Walkways and ramps 10 feet wide or greater, plaza areas special

feature areas

0.10 W/ft

0.11 W/ft

0.14 W/ft

Dining areas

0.65 W/ft

0.75 W/ft

0.95 W/ft

Stairways

0.6 W/ft

0.7 W/ft

Pedestrian tunnels

0.12 W/ft

0.14 W/ft

0.21 W/ft

Landscaping

0.03 W/ft

0.04 W/ft

Building Entrances and Exits

Pedestrian and vehicular entrances and exists

W/linear

foot of

opening

W/linear

foot of

opening

W/linear

foot of

opening

W/linear

foot of

opening

Entry canopies

0.2 W/ft

0.25 W/ft

0.4 W/ft

Loading docks

0.35 W/ft

Sales Canopies

Free-standing and attached

0.4 W/ft

0.6 W/ft

0.7 W/ft

Outdoor Sales

Open areas (including vehicle sales lots)

0.2 W/ ft

0.35 W/

0.5 W/ ft

Street frontage for vehicle sales lots in addition to “open area”

allowance

7 W/linear

foot

7 W/linear

foot

W/linear

foot

For SI: 1 foot = 304.8 mm, 1 watt per square foot = W/0.0929 m

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TABLE C405.5.3(3)

INDIVIDUAL LIGHTING POWER ALLOWANCES FOR BUILDING EXTERIORS

LIGHTING ZONES

Zone 1

Zone 2

Zone 3

Zone 4

Building facades

No Allowance

0.075 W/ft

of gross

above-grade wall

area

0.113 W/ft

of gross

above-grade wall

area

0.150 W/ft

of gross

above-grade wall

area

Automated teller

machines (ATM) and

night depositories

135 W per location plus 45 W per additional ATM per location

Uncovered entrances

and gatehouse

inspection stations at

guarded facilities

0.5 W/ft

Uncovered loading

areas for law

enforcement, fire,

ambulance and other

emergency service

vehicles

0.35 W/ft

Drive-up

windows/doors

200 W per drive-through

Parking near 24-hour

retail entrances

400 W per main entry

C405.5.3.1 Additional exterior lighting power. Any increase in the exterior lighting power allowance is

limited to the specific lighting applications indicated in Table C405.5.3(3). The additional power shall be

used only for the luminaires that are serving these applications and shall not be used for any other purpose.

C405.5.4 Gas lighting. Gas-fired lighting appliances shall not be equipped with continuously burning pilot

ignition systems.

C405.6 Electrical transformers. Low-voltage dry-type distribution electric transformers shall meet the minimum

efficiency requirements of Table C405.6 as tested and rated in accordance with the test procedure listed in DOE

10 CFR 431. The efficiency shall be verified through certification under an approved certification program or,

where no certification program exists, the equipment efficiency ratings shall be supported by data furnished by

the transformer manufacturer.

Exception: The following transformers are exempt:

1. Transformers that meet the Energy Policy Act of 2005 exclusions based on the DOE 10 CFR 431

definition of special purpose applications.

2. Transformers that meet the Energy Policy Act of 2005 exclusions that are not to be used in general

purpose applications based on information provided in DOE 10 CFR 431.

3. Transformers that meet the Energy Policy Act of 2005 exclusions with multiple voltage taps where the

highest tap is not less than 20 percent more than the lowest tap.

4. Drive transformers.

5. Rectifier transformers.

6. Auto-transformers.

7. Uninterruptible power system transformers.

8. Impedance transformers.

9. Regulating transformers.

10. Sealed and nonventilating transformers.

11. Machine tool transformer.

12. Welding transformer.

13. Grounding transformer.

14. Testing transformer.

CE-114 2018 Washington State Energy Code

TABLE C405.6

MINIMUM NOMINAL EFFICIENCY LEVELS FOR 10 CFR 431 LOW VOLTAGE DRY-TYPE DISTRIBUTION

TRANSFORMERS

Single Phase

Transformers

Three Phase

Transformers

kVA

Efficiency (%)

kVA

Efficiency (%)

97.70

97.89

98.00

98.23

37.5

98.20

98.40

98.30

98.60

98.50

112.5

98.74

100

98.60

150

98.83

167

98.70

225

98.94

250

98.80

300

99.02

333

98.90

500

99.14

750

99.23

1000

99.28

a. kiloVolt-Amp rating.

b. Nominal efficiencies shall be established in accordance with the DOE 10 CFR 431 test procedure for low voltage dry-

type transformers.

C405.7 Dwelling unit electrical energy consumption. Each dwelling unit located in a Group R-2 building shall

have a separate electrical meter. A utility tenant meter meets this requirement. See Section C409 for additional

requirements for energy metering and energy consumption management.

Exception: Dwelling units in other than Group R-2 apartment and live/work units are not required to provide a

separate electrical metering at each dwelling unit where electrical usage is metered separately for each of the

following building end uses:

1. Dwelling units.

2. Sleeping units.

3. Commercial kitchens.

4. Central laundries.

C405.8 Electric motor efficiency. All electric motors, fractional or otherwise, shall meet the minimum efficiency

requirements of Tables C405.8(1) through C405.8(4) when tested and rated in accordance with DOE 10 CFR.

The efficiency shall be verified through certification under an approved certification program, or, where no

certification program exists, the equipment efficiency rating shall be supported by data furnished by the motor

manufacturer.

Exception: The standards in this section shall not apply to the following exempt electric motors.

1. Air-over electric motors.

2. Component sets of an electric motor.

3. Liquid-cooled electric motors.

4. Submersible electric motors.

5. Inverter-only electric motors.

Fractional hp fan motors that are 1/12 hp or greater and less than 1 hp (based on output power) which are not

covered by Tables C405.8(3) and C405.8(4) shall be electronically commutated motors or shall have a minimum

motor efficiency of 70 percent when rated in accordance with DOE 10 CFR 431. These motors shall also have

the means to adjust motor speed for either balancing or remote control. Belt-driven fans may use sheave

adjustment for airflow balancing in lieu of a varying motor speed.

Exceptions:

1. Motors that are an integral part of specialized process equipment.

2. Where the motor is integral to a listed piece of equipment for which no complying motor has been

approved.

3. Motors used as a component of the equipment meeting the minimum efficiency requirements of

Section C403.3.2 and Tables C403.3.2(1) through C403.3.2(12), provided that the motor input is

included when determining the equipment efficiency.

4. Motors in the airstream within fan coils and terminal units that operate only when providing heating to

the space served.

2018 Washington State Energy Code CE-115

5. Fan motors that are not covered by Tables C405.8(1) through C405.8(4) and are used to power heat

recovery ventilators, energy recovery ventilators, or local exhaust fans in Group R subject to the

efficacy requirements of Section C403.8.4.

6. Domestic clothes dryer booster fans, range hood exhaust fans, and domestic range booster fans that

operate intermittently.

7. Radon and contaminated soil exhaust fans.

8. Group R heat recovery ventilator and energy recovery ventilator fans that are less than 400 cfm.

TABLE C405.8(1)

MINIMUM NOMINAL FULL-LOAD EFFICIENCY FOR NEMA DESIGN A, NEMA DESIGN B AND IEC DESIGN

N MOTORS (EXCLUDING FIRE PUMP) ELECTRIC MOTORS AT 60 HZ

a,b

Motor horsepower

(Standard kilowatt

equivalent)

Nominal full-load efficiency (%) as of June 1, 2016

2 pole

4 pole

6 pole

8 pole

Enclosed

Open

Enclosed

Open

Enclosed

Open

Enclosed

Open

1 (0.75)

77.0

85.5

82.5

75.5

1.5 (1.1)

84.0

86.5

87.5

86.5

78.5

77.5

2 (1.5)

85.5

86.5

88.5

87.5

84.0

86.5

3 (2.2)

86.5

85.5

89.5

88.5

85.5

87.5

5 (3.7)

88.5

86.5

89.5

86.5

88.5

7.5 (5.5)

89.5

88.5

91.7

91.0

90.2

86.5

89.5

10 (7.5)

90.2

89.5

91.7

91.0

91.7

89.5

90.2

15 (11)

91.0

90.2

92.4

93.0

91.7

89.5

90.2

20 (15)

91.0

93.0

91.7

92.4

90.2

91.0

25 (18.5)

91.7

93.6

93.0

90.2

91.0

30 (22)

91.7

93.6

94.1

93.0

93.6

91.7

40 (30)

92.4

94.1

91.7

50 (37)

93.0

94.5

94.1

92.4

60 (45)

93.6

95.0

94.5

92.4

93.0

75 (55)

93.6

95.4

95.0

94.5

93.6

94.1

100 (75)

94.1

93.6

95.4

95.0

93.6

94.1

125 (90)

95.0

94.1

95.4

95.0

94.1

150 (110)

95.0

94.1

95.8

95.4

94.1

200 (150)

95.4

95.0

96.2

95.8

95.4

94.5

94.1

250 (186)

95.8

95.0

96.2

95.8

95.0

300 (224)

95.8

95.4

96.2

95.8

350 (261)

95.8

95.4

96.2

95.8

400 (298)

95.8

96.2

95.8

450 (336)

95.8

96.2

500 (373)

95.8

96.2

a. Nominal efficiencies shall be established in accordance with DOE 10 CFR 431.

b. For purposes of determining the required minimum nominal full-load efficiency of an electric motor that has a

horsepower or kilowatt rating between two horsepower or two kilowatt ratings listed in this table, each such motor

shall be deemed to have a listed horsepower or kilowatt rating, determined as follows:

1. A horsepower at or above the midpoint between the two consecutive horsepowers shall be rounded up to

the higher of the two horsepowers.

2. A horsepower below the midpoint between the two consecutive horsepowers shall be rounded down to the

lower of the two horsepowers.

3. A kilowatt rating shall be directly converted from kilowatts to horsepower using the formula 1 kW =

(1/0.746) horsepower. The conversion should be calculated to three significant decimal places, and the

resulting horsepower shall be rounded in accordance with 1 or 2, whichever applies.

CE-116 2018 Washington State Energy Code

TABLE C405.8(2)

MINIMUM NOMINAL FULL-LOAD EFFICIENCY

FOR NEMA DESIGN C AND IEC DESIGN H MOTORS AT 60HZ

a,b

Motor horsepower

(Standard kilowatt equivalent)

Nominal full-load efficiency (%) as of June 1, 2016

4 pole

6 pole

8 pole

Enclosed

Open

Enclosed

Open

Enclosed

Open

1 (0.75)

85.5

82.5

75.5

1.5 (1.1)

86.5

87.5

86.5

78.5

77.5

2 (1.5)

86.5

88.5

87.5

84.0

86.5

3 (2.2)

89.5

88.5

85.5

87.5

5 (3.7)

89.5

86.5

88.5

7.5 (5.5)

91.7

91.0

90.2

86.5

89.5

10 (7.5)

91.7

91.0

91.7

89.5

90.2

15 (11)

92.4

93.0

91.7

89.5

90.2

20 (15)

93.0

91.7

92.4

90.2

91.0

25 (18.5)

93.6

93.0

90.2

91.0

30 (22)

93.6

94.1

93.0

93.6

91.7

40 (30)

94.1

91.7

50 (37)

94.5

94.1

92.4

60 (45)

95.0

94.5

92.4

93.0

75 (55)

95.4

95.0

94.5

93.6

94.1

100 (75)

95.4

95.0

93.6

94.1

125 (90)

95.4

95.0

94.1

150 (110)

95.8

95.4

94.1

200 (150)

96.2

95.8

95.4

94.5

94.1

NR - No requirement.

a. Nominal efficiencies shall be established in accordance with DOE 10 CFR 431.

b. For purposes of determining the required minimum nominal full-load efficiency of an electric motor that has a

horsepower or kilowatt rating between two horsepower or two kilowatt ratings listed in this table, each such motor

shall be deemed to have a listed horsepower or kilowatt rating, determined as follows:

1. A horsepower at or above the midpoint between the two consecutive horsepowers shall be rounded up to the

higher of the two horsepowers.

2. A horsepower below the midpoint between the two consecutive horsepowers shall be rounded down to the

lower of the two horsepowers.

3. A kilowatt rating shall be directly converted from kilowatts to horsepower using the formula 1 kW = (1/0.746)

horsepower. The conversion should be calculated to three significant decimal places, and the resulting

horsepower shall be rounded in accordance with 1 or 2, whichever applies.

2018 Washington State Energy Code CE-117

TABLE C405.8(3)

MINIMUM AVERAGE FULL LOAD EFFICIENCY FOR

POLYPHASE SMALL ELECTRIC MOTORS

NUMBER OF POLES ►

OPEN MOTORS

SYNCHRONOUS SPEED (RPM) ►

3600

1800

1200

MOTOR HORSEPOWER ▼

0.25

65.6

69.5

67.5

0.33

69.5

73.4

71.4

0.50

73.4

78.2

75.3

0.75

76.8

81.1

81.7

77.0

83.5

82.5

1.5

84.0

86.5

83.8

85.5

86.5

N/A

85.5

86.9

N/A

a. Average full load efficiencies shall be established in accordance with 10 CFR 431.

TABLE C405.8(4)

MINIMUM AVERAGE FULL LOAD EFFICIENCY FOR

CAPACITOR-START CAPACITOR-RUN AND CAPACITOR-

START INDUCTION-RUN SMALL ELECTRIC MOTORS

NUMBER OF POLES ►

OPEN MOTORS

SYNCHRONOUS SPEED (RPM) ►

3600

1800

1200

MOTOR HORSEPOWER ▼

0.25

66.6

68.5

62.2

0.33

70.5

72.4

66.6

0.50

72.4

76.2

0.75

76.2

81.8

80.2

80.4

82.6

81.1

1.5

81.5

83.8

N/A

82.9

84.5

N/A

84.1

N/A

a. Average full load efficiencies shall be established in accordance with 10 CFR. 431.

C405.9 Vertical and horizontal transportation systems and equipment. Vertical and horizontal

transportation systems and equipment shall comply with this section.

C405.9.1 Elevator cabs. For the luminaires in each elevator cab, not including signals and displays, the sum

of the lumens divided by the sum of the watts shall be not less than 35 lumens per watt. Ventilation fans in

elevators that do not have their own air conditioning system shall not consume more than 0.33 watts/cfm at

the maximum rated speed of the fan. Controls shall be provided that will de-energize ventilation fans and

lighting systems when the elevator is stopped, unoccupied and with its doors closed for over 15 minutes.

C405.9.2 Escalators and moving walks. Escalators and moving walks shall comply with ASME A17.1/CSA

B44 and shall have automatic controls configured to reduce speed to the minimum permitted speed in

accordance with ASME A17.1/CSA B44 or applicable local code when not conveying passengers.

Exception: A variable voltage drive system that reduces operating voltage in response to light loading

conditions may be provided in place of the variable speed function.

CE-118 2018 Washington State Energy Code

C405.9.3 Regenerative drive. An escalators designed either for one-way down operation only or for

reversible operation shall have a variable frequency regenerative drive that supplies electrical energy to the

building electrical system when the escalator is loaded with passengers whose combined weight exceeds 750

pounds.

C405.10 Controlled receptacles. At least 50 percent of all 125 volt 15- and 20-ampere receptacles installed in

private offices, open offices, conference rooms, rooms used primarily for printing and/or copying functions,

break rooms, individual workstations and classrooms, including those installed in modular partitions and

modular office workstation systems, shall be controlled as required by this section. In rooms larger than 200

square feet (19 m

), a controlled receptacle shall be located within 72 inches (1.8 m) of each uncontrolled

receptacle. Controlled receptacles shall be visibly differentiated from standard receptacles and shall be

controlled by one of the following automatic control devices:

1. An occupant sensor that turns receptacle power off when no occupants have been detected for a

maximum of 20 minutes.

2. A time-of-day operated control device that turns receptacle power off at specific programmed times and

can be programmed separately for each day of the week. The control device shall be configured to

provide an independent schedule for each portion of the building not to exceed 5,000 square feet (465 m

)

and not to exceed one full floor. The device shall be capable of being overridden for periods of up to two

hours by a timer in a location with access to occupants. Any individual override switch shall control the

controlled receptacles for a maximum area of 5,000 square feet (465 m

). Override switches for controlled

receptacles are permitted to control the lighting within the same area.

Exception: Receptacles designated for specific equipment requiring 24-hour operation, for building

maintenance functions, or for specific safety or security equipment are not required to be controlled by an

automatic control device and are not required to be located within 72 inches of a controlled receptacle.

C405.11 Voltage drop in feeders and branch circuits. The total voltage drop across the combination of

feeders and branch circuits shall not exceed five percent.

C405.12 Commissioning. Controlled receptacles and lighting systems shall be commissioned in accordance

with Section C408.

SECTION C406

EFFICIENCY PACKAGES

C406.1 Additional energy efficiency credit requirements. New buildings and changes in space conditioning,

change of occupancy and building additions in accordance with Chapter 5 shall comply with sufficient packages

from Table C406.1 so as to achieve a minimum number of six credits. Each area shall be permitted to apply for

different packages provided all areas in the building comply with the requirement for six credits. Areas included

in the same permit within mixed use buildings shall be permitted to demonstrate compliance by an area

weighted average number of credits by building occupancy achieving a minimum number of six credits.

Exceptions:

1. Low energy spaces in accordance with Section C402.1.1.1 and equipment buildings in accordance with

Section C402.1.2 shall comply with sufficient packages from Table C406.1 to achieve a minimum

number of three credits.

2. Building additions that have less than 1,000 square feet of conditioned floor area shall comply with

sufficient packages from Table C406.1 to achieve a minimum number of three credits.

C406.1.1 Tenant spaces. Initial tenant improvement shall comply with sufficient packages from Table

C406.1 to achieve a minimum number of six credits. In buildings with multiple tenant spaces, each tenant

space is permitted to apply for different packages provided all areas in the building comply with the

requirement for six credits.

C406.1.1.1 Applicable envelope and on-site renewable energy credits. Where an entire building or

building addition complies with Section C406.5, C406.10 or C406.11, under an initial tenant improvement

permit, tenant spaces within the building qualify for the number of credits assigned to the occupancy type

of the tenant space in accordance with Table C406.1.

2018 Washington State Energy Code CE-119

TABLE C406.1

EFFICIENCY PACKAGE CREDITS

Code Section

Commercial Building Occupancy

Group R-1

Group R-2

Group B

Group E

Group M

All Other

Additional Efficiency Credits

1. More efficient HVAC

performance in accordance

with Section C406.2

2.0

3.0

2.0

1.0

2.0

2. Reduced lighting power:

Option 1 in accordance with

Section C406.3.1

1.0

2.0

3.0

2.0

3. Reduced lighting power:

Option 2 in accordance with

Section C406.3.2

2.0

3.0

4.0

6.0

4.0

4. Enhanced lighting controls in

accordance with Section

C406.4

1.0

5. On-site supply of renewable

energy in accordance with

C406.5

3.0

6. Dedicated outdoor air system

in accordance with Section

C406.6

4.0

7. High performance dedicated

outdoor air system in

accordance with Section

C406.7

4.0

8. High-efficiency service water

heating in accordance with

Sections C406.8.1 and

C406.8.2

4.0

5.0

8.0

9. High performance service

water heating in multi-family

buildings in accordance with

Section C406.9

7.0

8.0

10. Enhanced envelope

performance in accordance

with Section C406.10

3.0

6.0

3.0

4.0

11. Reduced air infiltration in

accordance with Section

C406.11

1.0

2.0

1.0

12. Enhanced commercial

kitchen equipment in

accordance with Section

C406.12

5.0

5.0 (Group

A-2 only)

a. Projects using this option may not use Item 2.

b. This option is not available to buildings subject to the prescriptive requirements of Section C403.3.5.

c. Buildings or building areas that are exempt from thermal envelope requirements in accordance with Sections

C402.1.1 and C402.1.2 do not qualify for this package.

C406.1.1.2 Applicable HVAC and service water heating credits. Where HVAC and service water heating

systems and services are installed and comply with Section C406.2 or C406.8 under an initial tenant

improvement permit, those systems and services shall be considered a part of the tenant space. Tenant

spaces qualify for the credits assigned to the occupancy type of the tenant space in accordance with Table

C406.1 if the tenant space includes the distribution system and equipment that the central HVAC systems or

service water heating systems were designed to support.

CE-120 2018 Washington State Energy Code

Exception: Previously occupied tenant spaces in existing buildings that comply with this code in

accordance with Section C501.

C406.2 More efficient HVAC equipment and fan performance. No less than 90 percent of the total HVAC

capacity serving the total conditioned floor area of the entire building, or tenant space in accordance with

Section C406.1.1, shall comply with Sections C406.2.1 through C406.2.3. For systems required to comply with

Section C403.1.1, HVAC total system performance ratio, exceed the minimum requirement by 10 percent.

Exception: In low energy spaces complying with Section C402.1.1 and semi-heated spaces complying with

Section C402.1.1.2, no less than 90 percent of the installed heating capacity is provided by electric infrared or

gas-fired radiant heating equipment for localized heating applications. Stand-alone supply, return and exhaust

fans shall comply with Section C406.2.3.

C406.2.1 HVAC system selection. Equipment installed shall be types that are listed in Tables C403.3.2(1)

through C403.3.2(12) or a combination thereof. Electric resistance heating does not meet this requirement.

Exception: Allowed equipment not listed in Tables C403.3.2(1) through C403.3.2(12):

1. Air-to-water heat pumps.

2. Heat recovery chillers.

C406.2.2 Minimum equipment efficiency. Equipment shall exceed the minimum efficiency requirements

listed in Tables C403.3.2(1) through C403.3.2(12) by 15 percent, in addition to the requirements of Section

C403. Where multiple performance requirements are provided, the equipment shall exceed all requirements

by 15 percent.

Exceptions:

1. Equipment that is larger than the maximum capacity range indicated in Tables C403.3.2(1) through

C403.3.2(12) shall utilize the values listed for the largest capacity equipment for the associated

equipment type shown in the table.

2. Equipment complying with the exception to Section C406.2.1 is not required to comply with the

minimum equipment efficiency requirement.

3. Compliance may be demonstrated by calculating a total weighted average percentage for all heating

and cooling equipment combined. All equipment shall have efficiency that is no less than 5 percent

better than the minimum required efficiency in Tables C403.3.2(1) through C403.3.2(12), and the

resulting weighted average percentage for all equipment performance requirements shall exceed 15

percent. Calculation shall include heating and cooling capacities for all equipment, percentage better

or worse than minimum required efficiency per Tables C403.3.2(1) through C403.3.2(12) for each

performance requirement (SEER, EER/IEER, COP, HSPF, E

, E

and AFUE), and the total weighted

average efficiency percentage.

4. Hot water boilers with input capacity greater than 2,500,000 Btu/h shall be considered to comply with

this section with a minimum thermal efficiency of 95 percent E

per the test procedure in 10 CFR Part

431.

C406.2.3 Minimum fan efficiency. Stand-alone supply, return and exhaust fans designed for operating with

motors over 750 watts (1 hp) shall have a fan efficiency grade of not less than FEG 71 as defined in AMCA

205. The total efficiency of the fan at the design point of operation shall be within 10 percentage points of

either the maximum total efficiency of the fan or the static efficiency of the fan.

C406.3 Reduced lighting power. Interior lighting within the whole building, building addition or tenant space

shall comply with Section C406.3.1 or C406.3.2. Dwelling units and sleeping units within the building shall

comply with Section C406.3.3.

C406.3.1 Reduced lighting power option 1. The total connected interior lighting power calculated in

accordance with Section C405.4.1 shall be 90 percent or less of the lighting power values specified in Table

C405.4.2(1) times the floor area for the building types, or by using 90 percent or less of the total interior

lighting power allowance calculated in accordance with Section C405.4.2.

C406.3.2 Reduced lighting power option 2. The total connected interior lighting power calculated in

accordance with Section C405.4.1 shall be 80 percent or less of the lighting power values specified in Table

C405.4.2(1) times the floor area for the building types, or by using 80 percent or less of the total interior

lighting power allowance calculated in accordance with Section C405.4.2.

2018 Washington State Energy Code CE-121

C406.3.3 Lamp fraction. No less than 95 percent of the permanently installed light fixtures in dwelling units

and sleeping units shall be provided by high efficacy lamps with a minimum efficacy of 65 lumens per watt.

C406.4 Enhanced digital lighting controls. No less than 90 percent of the total installed interior lighting power

within the whole building, building addition or tenant space shall comply with Section C406.4.1.

C406.4.1 Lighting controls function. Interior lighting shall be located, scheduled and operated in

accordance with Section C405.2, and shall be configured with the following enhanced control functions:

1. Luminaires shall be configured for continuous dimming.

2. Each luminaire shall be individually addressed.

Exceptions to Item 2:

1. Multiple luminaires mounted on no more than 12 linear feet of a single lighting track and

addressed as a single luminaire.

2. Multiple linear luminaires that are ganged together to create the appearance of a single longer

fixture and addressed as a single luminaire, where the total length of the combined luminaires is

not more than 12 feet.

3. No more than eight luminaires within a daylight zone are permitted to be controlled by a single daylight

responsive control.

4. Luminaires shall be controlled by a digital control system configured with the following capabilities:

4.1. Scheduling and illumination levels of individual luminaires and groups of luminaires are capable of

being reconfigured through the system.

4.2. Load shedding.

4.3. In open and enclosed offices, the illumination level of overhead general illumination luminaires are

configured to be individually adjusted by occupants.

4.4. Occupancy sensors and daylight responsive controls are capable of being reconfigured through

the system.

5. Construction documents shall include submittal of a Sequence of Operations, including a specification

outlining each of the functions required by this section.

C406.5 On-site renewable energy. A whole building, building addition or tenant space shall be provided with

on-site renewable energy systems with an annual production per square foot of no less than the value specified

in Table C406.5 based on the total conditioned floor area of the whole building. The on-site renewable used in

this option shall be separate from on-site renewables used as part of Section C406.7 or used to qualify for any

exception in this code.

TABLE C406.5

ON-SITE RENEWABLE ENERGY SYSTEM RATING

(PER SQUARE FOOT)

Building Area Type

kBTU per

year

kWh per

year

Assembly

1.8

0.53

Dining

10.7

3.14

Hospital

3.6

1.06

Hotel/Motel

2.0

0.59

Multi-family residential

0.50

0.15

Office

0.82

0.24

Other

2.02

0.59

Retail

1.31

0.38

School/University

1.17

0.34

Supermarket

5.0

1.47

Warehouse

0.43

0.13

CE-122 2018 Washington State Energy Code

C406.6 Dedicated outdoor air system (DOAS). No less than 90 percent of the total conditioned floor area of

the whole building, building addition or tenant space, excluding floor area of unoccupied spaces that do not

require ventilation per the International Mechanical Code, shall be served by DOAS installed in accordance with

Section C403.3.5. This option is not available to buildings subject to the prescriptive requirements of Section

C403.3.5.

C406.7 High performance dedicated outdoor air system (DOAS). A whole building, building addition or

tenant space which includes a DOAS complying with Section C406.6 shall also provide minimum sensible

effectiveness of heat recovery of 80 percent and DOAS total combined fan power less than 0.5 W/cfm of

outdoor air. For the purposes of this section, total combined fan power includes all supply, exhaust, recirculation

and other fans utilized for the purpose of ventilation.

C406.8 Reduced energy use in service water heating. Buildings with service hot water heating equipment

that serves the whole building, building addition or tenant space shall comply with Sections C406.8.1 and

C406.8.2.

C406.8.1 Building type. Not less than 90 percent of the conditioned floor area of the whole building, building

addition or tenant space shall be of the following types:

1. Group R-1: Boarding houses, hotels or motels.

2. Group I-2: Hospitals, psychiatric hospitals and nursing homes.

3. Group A-2: Restaurants and banquet halls or buildings containing food preparation areas.

4. Group F: Laundries.

5. Group R-2.

6. Group A-3: Health clubs and spas.

7. Buildings with a service hot water load of 10 percent or more of total building energy loads, as shown

with an energy analysis as described in Section C407 or as shown through alternate service hot water

load calculations showing a minimum service water energy use of 15 k/Btu per square foot per year, as

approved by the building official..

C406.8.2 Load fraction. Not less than 60 percent of the annual service hot water heating energy use, or not

less than 100 percent of the annual service hot water heating energy use in buildings with water-cooled

systems subject to the requirements of Section C403.9.5 or qualifying for one of its exceptions, shall be

provided by one or more of the following:

1. Service hot water system delivering heating requirements using heat pump technology with a minimum

COP of 3.0. For air-source equipment, the COP rating will be reported at the design leaving heat pump

water temperature with an entering air temperature of 60°F (15.6°C) or lower. For water-source

equipment, the COP rating will be reported at the design leaving load water temperature with an

entering water temperature of 74°F (23.3°C) or lower.

2. Waste heat recovery from service hot water, heat recovery chillers, building equipment, process

equipment, or other approved system. Qualifying heat recovery must be above and beyond heat

recovery required by other sections of this code.

3. On site renewable energy water-heating systems.

C406.9 High performance service water heating in multifamily buildings. For a whole building, building

addition, or tenant space with not less than 90 percent of the conditioned floor area being Group R-2 occupancy,

not less than 90 percent of the annual building service hot water energy use shall be provided by a heat pump

system with a minimum COP of 3.0. This efficiency package is allowed be taken in addition to Section C406.8.2.

C406.10 Enhanced envelope performance. The Proposed Total UA of the thermal envelope of the whole

building or building addition shall be 15 percent lower than the Allowable Total UA for an area of identical

configuration and fenestration area in accordance with Section C402.1.5 and Equation 4-2.

C406.11 Reduced air infiltration. Measured air infiltration of the total conditioned floor area of the whole

building, fully isolated building addition or tenant space shall comply with Section C406.11.1.

C406.11.1 Air leakage testing and verification. Air infiltration shall be verified by whole building

pressurization testing conducted in accordance with ASTM E779 or ASTM E1827 by an independent third

party. The measured air leakage rate of the building envelope shall not exceed 0.17 cfm/ft

under a pressure

differential of 0.3 in. water (75 Pa), with the calculated surface area being the sum of the above and below

grade building envelope. A report that includes the tested surface area, floor area, air by volume, stories

2018 Washington State Energy Code CE-123

above grade, and leakage rates shall be submitted to the code official and the building owner.

Exception: Where the conditioned floor area of the building is not less than 250,000 ft

(25,000 m

), air

leakage testing shall be permitted to be conducted on representative above grade sections of the building

provided the conditioned floor area of tested areas is no less than 25 percent of the conditioned floor area of

the building and are tested in accordance with this section.

C406.12 Enhanced commercial kitchen equipment. For buildings and spaces designated as Group A-2, or

facilities whose primary business type involves the use of a commercial kitchen with at least one gas or electric

fryer, all fryers, dishwashers, steam cookers and ovens shall comply with all of the following:

1. Achieve the ENERGY STAR label in accordance with the specifications current as of January 1, 2018.

2. Be installed prior to the issuance of the certificate of occupancy.

3. Have the ENERGY STAR qualified model number listed on the construction documents submitted for

permitting.

SECTION C407

TOTAL BUILDING PERFORMANCE

C407.1 Scope. This section establishes criteria for compliance using total building performance. All systems

and loads shall be included in determining the total building performance including, but not limited to: Heating

systems, cooling systems, service water heating, fan systems, lighting power, receptacle loads and process

loads.

Exception: Energy used to recharge or refuel vehicles that are used for on-road and off-site transportation

purposes.

C407.2 Mandatory requirements. Compliance with this section requires compliance with those sections shown

in Table C407.2.

The building permit application for projects utilizing this method shall include in one submittal all building and

mechanical drawings and all information necessary to verify that the building envelope and mechanical design

for the project corresponds with the annual energy analysis. If credit is proposed to be taken for lighting energy

savings, then an electrical permit application shall also be submitted and approved prior to the issuance of the

building permit. If credit is proposed to be taken for energy savings from other components, then the

corresponding permit application (e.g., plumbing, boiler, etc.) shall also be submitted and approved prior to the

building permit application. Otherwise, components of the project that would not be approved as part of a

building permit application shall be modeled the same in both the proposed building and the standard reference

design and shall comply with the requirements of this code.

C407.3 Performance-based compliance. Compliance with this section requires compliance with ASHRAE

Standard 90.1 Appendix G, Performance Rating Method, in accordance with Standard 90.1 Section 4.2.1 with

the following modifications..

1. The mandatory requirements of Section G1.2.1a of Standard 90.1 are not required to be met.

2. The reduction in annual carbon emissions of the proposed building design associated with on-site

renewable energy shall not be more than 3 percent of the total carbon emissions of the baseline

building design.

3. References to energy cost in Section 4.2.1.1 and Appendix G shall be replaced by carbon emissions

calculated by multiplying site energy consumption by the carbon emission factor from Table C407.3(1).

4. The building performance factors in Table C4.2.1.1 shall be replaced with those in Table C407.3(2).

CE-124 2018 Washington State Energy Code

TABLE C407.2

MANDATORY COMPLIANCE MEASURES FOR TOTAL BUILDING PERFORMANCE METHOD

Section

Title

Comments

Envelope

C402.5

Air Leakage

Mechanical

C403.1.2

Calculation of heating and cooling loads

C403.1.3

Data centers

C403.2

System design

C403.3.1

Equipment and system sizing

C403.3.2

HVAC equipment performance requirements

C403.3.6

Ventilation for Group R occupancy

C403.4

HVAC system controls

C403.4.1

Thermostatic controls

Except for C403.4.1.4

C403.4.2

Off-hour controls

Except for Group R

C403.4.7

Combustion heating equipment controls

C403.4.8

Group R-1 hotel/motel guestrooms

See Section C403.7.4

C403.4.9

Group R-2 and R-3 dwelling units

C403.4.10

Group R-2 sleeping units

C403.4.11

Direct digital control systems,

C403.5.5

Economizer fault detection and diagnostics (FDD)

C403.7

Ventilation and exhaust systems

Except for C403.7.6

C403.8

Fan and fan controls

C403.9.1.1

Variable flow controls

For cooling tower fans ≥ 7.5 hp

C403.9.1.2

Limitation on centrifugal fan cooling towers

For open cooling towers

C403.10

Construction of HVAC elements

C403.11

Mechanical systems located outside of the building thermal envelope

Service Water Heating

C404

Service Water Heating

Lighting and Electrical

C405.1

General

C405.2

Lighting controls

C405.3

Exit signs

C405.4

Interior lighting power

C405.5

Exterior building lighting power

C405.6

Electrical transformers

C405.7

Dwelling unit energy consumption

C405.8

Electric motor efficiency

C405.9

Vertical and horizontal transportation

C405.10

Controlled receptacles

C405.11

Voltage drop in feeders

Other Requirements

C407

Total Building Performance

C408

System commissioning

C409

Energy metering

C410

Refrigeration requirements

C411

Solar readiness

2018 Washington State Energy Code CE-125

TABLE C407.3(1)

CARBON EMISSIONS FACTORS

Type

CO2e (lb/unit)

Unit

Electricity

0.70

kWh

Natural Gas

11.7

Therm

Oil

19.2

Gallon

Propane

10.5

Gallon

Other

195.00

mmBtu

On-site renewable energy

0.00

a. District energy systems may use alternative emission factors

supported by calculations approved by the code official.

TABLE C407.3(2)

BUILDING PERFORMANCE FACTORS (BPF) TO BE USED

FOR COMPLIANCE WITH SECTION C407.3

Building Area Type

Building Performance Factor

Multifamily

0.58

Healthcare/hospital

0.54

Hotel/motel

0.64

Office

0.56

Restaurant

0.70

Retail

0.47

School

0.36

Warehouse

0.48

All Others

0.54

C407.3.1 Limits on non-mandatory measures. The Proposed Total UA of the proposed building shall be no

more than 20 percent higher than the Allowed Total UA as defined in Section C402.1.5.

SECTION C408

SYSTEM COMMISSIONING

C408.1 General. A building commissioning process led by a certified commissioning professional and functional

testing requirements shall be completed for mechanical systems in Section C403; service water heating

systems in Section C404; controlled receptacle and lighting control systems in Section C405; equipment,

appliance and systems installed to comply with Section C406 or C407;senergy metering in Section C409; and

refrigeration systems in Section C410.

Exception: Buildings, or portions thereof, which are exempt from Sections C408.2 through C408.7 may be

excluded from the commissioning process.

1. Mechanical systems are exempt from the commissioning process where the installed total mechanical

equipment capacity is less than 240.000 Btu/h cooling capacity and less than 300,000 Btu/h heating

capacity.

2. Service water heating systems are exempt from the commissioning process in buildings where the

largest service water heating system capacity is less than 200,000 Btu/h and where there are no pools

or permanent spas.

CE-126 2018 Washington State Energy Code

3. Lighting control systems are exempt from the commissioning process in buildings where both the total

installed lighting load is less than 20 kW and the lighting load controlled by occupancy sensors or

automatic daylighting controls is less than 10 kW.

4. Refrigeration systems are exempt from the commissioning process if they are limited to self-contained

units.

C408.1.1 Commissioning in construction documents. Construction documents shall clearly indicate

provisions for commissioning process. The construction documents shall minimally include the following:

1. A narrative description of the activities that will be accomplished during the commissioning process. At a

minimum, the commissioning process is required to include:

1.1. Development and execution of the commissioning plan, including all subsections of Section

C408.1.2;

1.2. The certified commissioning professional’s review of the building documentation and close out

submittals in accordance with Section C103.6; and

1.3. The commissioning report in accordance with Section C408.1.3.

2. Roles, responsibilities and required qualifications of the certified commissioning professional.

3. A listing of the specific equipment, appliances or systems to be tested.

C408.1.2 Commissioning plan. A commissioning plan shall be developed by the project's certified

commissioning professional and shall outline the organization, schedule, allocation of resources, and

documentation requirements of the commissioning process. The plan shall also include the following:

1. A narrative description of the activities that will be accomplished during each phase of commissioning,

including the personnel intended to accomplish each of the activities, systems testing and balancing,

functional performance testing, and verification of the building documentation requirements in Section

C103.6.

2. Roles and responsibilities of the commissioning team, including the name and statement of

qualifications of the certified commissioning professional.

3. A listing of the specific equipment, appliances or systems to be tested and a description of the tests to

be performed.

C408.1.2.1 In-house commissioning disclosure and conflict management plan. Where the certified

commissioning professional’s contract or employment is other than directly with the building owner, an in-house

commissioning disclosure and conflict management plan shall be a part of the commissioning process. A copy

shall be included in the commissioning plan. This plan shall disclose the certified commissioning professional’s

contractual relationship with other team members and provide a conflict management plan demonstrating that

the certified commissioning professional is free to identify any issues discovered and report directly to the

owner.

C408.1.2.2 Functional performance testing. Functional performance testing shall be conducted for

mechanical systems in Sections C403; service water heating systems in Section C404; controlled

receptacles and lighting control systems in Section C405; equipment, appliances and systems installed to

comply with Section C406 or C407; energy metering in Section C409; and refrigeration systems in Section

C410. Written procedures which clearly describe the individual systematic test procedures, the expected

system response or acceptance criteria for each procedure, the actual response or findings, and any

pertinent discussion shall be followed. This testing shall include control systems which will be tested to

document that control devices, components, equipment, and systems are calibrated and adjusted to operate

in accordance with approved construction documents. Testing shall affirm the conditions required within

Sections C408.2 through C408.7 under system testing.

C408.1.2.3 Functional performance testing - sampling. For projects with seven or fewer similar systems,

each system shall be tested. For projects with more than seven systems, testing shall be done for each

unique combination of controls type. Where multiples of each unique combination of control types exist, no

fewer than 20 percent of each combination shall be tested unless the code official or design professional

requires a higher percentage to be tested. Where 30 percent or more of the tested system fail, all remaining

identical combinations shall be tested.

C408.1.2.4 Deficiencies. Deficiencies found during testing shall be resolved including corrections and

retesting.

2018 Washington State Energy Code CE-127

C408.1.3 Commissioning report. A commissioning report shall be completed and certified by the certified

commissioning professional and delivered to the building owner or owner's authorized agent. The report shall

be organized with mechanical, service water heating, controlled receptacle and lighting control systems,

energy metering, and refrigeration findings in separate sections to allow independent review. The report shall

record the activities and results of the commissioning process and be developed from the final commissioning

plan with all of its attached appendices. The report shall include:

1. Results of functional performance tests.

2. Disposition of deficiencies found during testing, including details of corrective measures used or

proposed.

3. Functional performance test procedures used during the commissioning process including measurable

criteria for test acceptance, provided herein for repeatability.

4. Commissioning plan.

5. Testing, adjusting and balancing report.

Exception: Deferred tests which cannot be performed at the time of report preparation due to climatic

conditions.

C408.1.4 Commissioning process completion requirements. Prior to the final mechanical, plumbing and

electrical inspections or obtaining a certificate of occupancy, the certified commissioning professional shall

provide evidence of building commissioning in accordance with the provisions of this section.

C408.1.4.1 Commissioning compliance. Buildings, or portions thereof, shall not be considered acceptable

for a final inspection pursuant to Section C104.2.6 until the code official has received a letter of transmittal

from the building owner or owner’s representative acknowledging that the building owner or owner's

authorized agent has received the Commissioning Report. Completion of Commissioning Compliance

Checklist (Figure C408.1.4.1) is deemed to satisfy this requirement. Phased acceptance of Commissioning

Compliance Checklist for portions of the work specific to the trade that is being inspected is permissible

where accepted by the code official and where the certified commissioning professional remains responsible

for completion of the commissioning process. If there are unresolved deficiencies when the final inspection

is scheduled, the Commissioning Report shall be submitted and shall describe the unresolved deficiencies.

C408.1.4.3 Copy of report. The code official shall be permitted to require that a copy of the Commissioning

Report be made available for review by the code official.

C408.2 Mechanical systems commissioning. Mechanical equipment and controls subject to Section C403

shall be included in the commissioning process required by Section C408.1. The commissioning process shall

minimally include all energy code requirements for which the code states that equipment or controls shall "be

capable of" or "configured to" perform specific functions.

Exception: Mechanical systems are exempt from the commissioning process where the installed total

mechanical equipment capacity is less than 240,000 Btu/h cooling capacity and less than 300,000 Btu/h

heating capacity.

C408.2.1 Reserved.

CE-128 2018 Washington State Energy Code

FIGURE C408.1.4.1

COMMISSIONING COMPLIANCE CHECKLIST

Project

Information

Project Name:

Project Address:

Certified Commissioning Professional:

Type of ISO Certification and Number:

Supporting

Documents



Manuals, record documents and training have been completed or are scheduled (Section C103.6)

 Building operations and maintenance information (C103.6.2) have been submitted to the owner

or scheduled date: _______________________________________________________________

 Manuals (C103.6.2.1) have been submitted to the owner or scheduled date: __________________

 Compliance documentation (C103.6.3) has been provided to the owner or scheduled date: _____

 System operation training (C103.6.4) has been provided to the owner or scheduled date: ________

Commissioning

Plan



Commissioning Plan was used during construction (Section C408.1.2)

Commissioning

Report



Commissioning Report has been submitted (Section C408.1.3)

Commissioned

Systems



Mechanical Systems were included in the commissioning process (Section C408.2)



Testing, adjusting and balancing is complete (Section C408.2.2)



There are unresolved deficiencies with the mechanical systems. These are described in the attached

Commissioning Report submitted to the Owner.



Service Water Heating Systems were included in the commissioning process (Section C408.3)



There are unresolved deficiencies with the service water heating systems. These are described in the

attached Commissioning Report submitted to the Owner.



Controlled receptacles and lighting control systems were included in the commissioning process

(Section C408.4)



There are unresolved deficiencies with the electrical power and/or automatic lighting controls. These are

described in the attached Commissioning Report submitted to the Owner.



Additional systems were included in the commissioning process (Section C408.5)



There are unresolved deficiencies with systems required by C406 or C407. These are described in the

attached Commissioning Report submitted to the Owner.



Metering systems were included in the commissioning process (Section C408.6)



There are unresolved deficiencies with the metering system. These are described in the attached

Commissioning Report submitted to the Owner.



Refrigeration systems were included in the commissioning process (Section C408.7)



There are unresolved deficiencies with systems required by Section C410. These are described in the

attached Commissioning Report submitted to the Owner.

Certification



I hereby certify that requirements for Section C408 System Commissioning have been completed in

accordance with the Washington State Energy Code, including all items above.

----------------------------------------------------------------------------------------------------------------------------------------------

Certified Commissioning Professional Date



I hereby certify that requirements for Section C408 System Commissioning have been completed in

accordance with the Washington State Energy Code, including all items above.

----------------------------------------------------------------------------------------------------------------------------------------------

Building Owner or Owner’s Representative Date

2018 Washington State Energy Code CE-129

C408.2.2 Systems adjusting and balancing. HVAC systems shall be balanced in accordance with generally

accepted engineering standards. Air and water flow rates shall be measured and adjusted to deliver final flow

rates within the tolerances provided in the project specifications. Test and balance activities shall include air

system and hydronic system balancing.

C408.2.2.1 Air systems balancing. Each supply air outlet and zone terminal device shall be equipped with

means for air balancing in accordance with the requirements of Chapter 6 of the International Mechanical

Code. Discharge dampers used for air system balancing are prohibited on constant volume fans and

variable volume fans with motors 10 hp (18.6 kW) and larger. Air systems shall be balanced in a manner to

first minimize throttling losses then, for fans with system power of greater than 1 hp (0.74 kW), fan speed

shall be adjusted to meet design flow conditions.

Exception: Fans with fan motors of 1 hp (0.74 kW) or less.

C408.2.2.2 Hydronic systems balancing. Individual hydronic heating and cooling coils shall be equipped

with means for balancing and measuring flow. Hydronic systems shall be proportionately balanced in a

manner to first minimize throttling losses, then the pump impeller shall be trimmed or pump speed shall be

adjusted to meet design flow conditions. Each hydronic system shall have either the capability to measure

pressure across the pump, or test ports at each side of each pump.

Exception: The following equipment is not required to be equipped with means for balancing or

measuring flow:

1. Pumps with pump motors of 5 hp (3.7 kW) or less.

2. Where throttling results in no greater than five percent of the nameplate horsepower draw above

that required if the impeller were trimmed.

C408.2.3 System testing. Functional performance testing shall demonstrate the components, systems, and

system-to-system interfacing relationships are installed and operate in accordance with approved

construction documents. Testing shall include the sequence of operation, and be conducted under full-load,

part-load and the following conditions:

1. All modes as described in the sequence of operation;

2. Redundant or automatic back-up mode;

3. Performance of alarms; and

4. Mode of operation upon a loss of power and restoration of power.

C408.3 Service water heating systems commissioning. Service water heating equipment and controls

subject to Section C404 shall be included in the commissioning process required by Section C408.1. The

commissioning process shall minimally include equipment and components installed to meet all energy code

requirements for devices to “start,” “automatically turn off,” “automatically adjust,” “limit operation,” and “limit the

temperature” and “be configured to.”

C408.3.1 System testing. Functional performance testing shall demonstrate that heaters, piping, distribution

systems, and system-to-system interfacing relationships are installed and operate in accordance with

approved construction documents. Testing shall include the sequence of operation, and be conducted under

at least 50 percent water heating load, part-load and the following conditions:

1. Normal operation;

2. Redundant or automatic back-up mode;

3. Performance of alarms; and

4. Mode of operation upon a loss of power and restoration of power.

C408.4 Controlled receptacle and lighting control system commissioning. Controlled receptacles and

lighting control systems subject to Section C405 shall be included in the commissioning process required by

Section C408.1. The configuration and function of controlled receptacles and lighting control systems required

by this code shall be tested and shall comply with Section C408.4.1.

Exception: Lighting control systems are exempt from the commissioning process in buildings where:

1. The total installed lighting load is less than 20 kW, and

2. The lighting load controlled by occupancy sensors or automatic daylighting controls is less than 10 kW.

CE-130 2018 Washington State Energy Code

C408.4.1 System testing. Functional performance testing shall demonstrate that occupant sensors, time

switches, manual overrides, night sweep-off, daylight responsive control, and controlled receptacles are

installed and operate in accordance with approved construction documents. Testing shall include the

sequence of operation and be conducted under the following conditions:

1. Normal operation;

2. Redundant or automatic back-up mode;

3. Performance of alarms; and

4. Mode of operation upon a loss of power and restoration of power.

C408.5 Systems installed to meet Section C406 or C407. Equipment, components, controls or configuration

settings for systems which are included in the project to comply with Section C406 or C407 shall be included in

the commissioning process required by Section C408.1.

C408.5.1 System testing. Functional performance testing for these appliances, equipment, components,

controls and/or configuration settings shall demonstrate operation, function and maintenance serviceability for

each of the commissioned systems in accordance with the approved construction documents.

C408.6 Metering system commissioning. Energy metering systems required by Section C409 shall comply

with Section C408.6 and be included in the commissioning process required by Section C408.1. The

commissioning process shall include all energy metering equipment and controls required by Section C409.

C408.6.1 System testing. Functional performance testing shall demonstrate that energy source meters, end-

use meters, data acquisition systems, and energy displays are installed and operate in accordance with

approved construction documents. . At a minimum, testing shall confirm that:

1. The metering system devices and components work properly under low and high load conditions.

2. The metered data is delivered in a format that is compatible with the data collection system.

3. The energy display is in a location with access to building operation and management personnel.

4. The energy display meets code requirements regarding views required in Section C409.4.3. The display

shows energy data in identical units (e.g., kWh).

C408.7 Refrigeration system commissioning. All installed refrigeration systems subject to Section C410 shall

be included in the commissioning process required by Section C408.1.

Exceptions:

1. Self-contained refrigeration systems are exempt from the commissioning process.

2. Total installed capacity for refrigeration is equal to or less than 240 kBtu/h.

C408.7.1 System Testing. Functional performance testing shall demonstrate that compressors, heat

exchangers, piping, distribution systems, and system-to-system interfacing relationships are installed and

operate in accordance with approved construction documents. Testing shall include the sequence of operation

and be conducted under full-load at, part-load and the following conditions:

1. Normal mode;

2. Redundant or automatic back-up mode;

3. Performance of alarms; and

4. Mode of operation upon a loss of power and restoration of power.

SECTION C409

ENERGY METERING AND ENERGY CONSUMPTION MANAGEMENT

C409.1 General. All new buildings and additions shall have the capability of metering source energy for on-site

renewable energy production in accordance with Section C409.2.4 and the end-use energy usage for electric

vehicle charging in accordance with Section C409.3.4. New buildings and additions with a gross conditioned

floor area over 50,000 square feet shall comply with Section C409. Buildings shall be equipped to measure,

monitor, record and display energy consumption data for each energy source and end use category per the

provisions of this section, to enable effective energy management.

Exceptions:

1. Tenant spaces smaller than 50,000 ft

within buildings if the tenant space has its own utility service and

utility meters.

2018 Washington State Energy Code CE-131

2. Buildings in which there is no gross conditioned floor area over 25,000 square feet, including building

common area, that is served by its own utility services and meters.

C409.1.1 Alternate metering methods. Where approved by the building official, energy use metering

systems may differ from those required by this section, provided that they are permanently installed and that

the source energy measurement, end use category energy measurement, data storage and data display have

similar accuracy to and are at least as effective in communicating actionable energy use information to the

building management and users, as those required by this section.

C409.1.2 Conversion factor. Any threshold stated in kW shall include the equivalent BTU/h heating and

cooling capacity of installed equipment at a conversion factor of 3,412 Btu per kW at 50 percent demand.

C409.1.3 Dwelling units. See Sections C404.9 and C405.7 for additional metering requirements for Group R-

2 dwelling units.

C409.2 Energy source metering. Buildings shall have a meter at each energy source. For each energy supply

source listed in Section C409.2.1 through C409.2.4, meters shall collect data for the whole building or for each

separately metered portion of the building where not exempted by the exception to Section C409.1.

Exceptions:

1. Energy source metering is not required where end use metering for an energy source accounts for all

usage of that energy type within a building, and the data acquisition system accurately totals the energy

delivered to the building or separately metered portion of the building.

2. Solid fuels such as coal, firewood or wood pellets that are delivered via mobile transportation do not

require metering.

C409.2.1 Electrical energy. This category shall include all electrical energy supplied to the building and its

associated site, including site lighting, parking, recreational facilities, and other areas that serve the building

and its occupants.

C409.2.2 Gas and liquid fuel supply energy. This category shall include all natural gas, fuel oil, propane

and other gas or liquid fuel energy supplied to the building and site.

C409.2.3 District energy. This category shall include all net energy extracted from district steam systems,

district chilled water loops, district hot water systems, or other energy sources serving multiple buildings.

C409.2.4 Site-generated renewable energy. This category shall include all net energy generated from on-

site solar, wind, geothermal, tidal or other natural sources. For buildings exempt from data collection systems,

the data from these meters is permitted to either be stored locally using a manual totalizing meter or other

means at the meter or fed into a central data collection system.

C409.3 End-use metering. Meters shall be provided to collect energy use data for each end-use category listed

in Sections C409.3.1 through C409.3.7. These meters shall collect data for the whole building or for each

separately metered portion of the building where not exempted by the exception to Section C409.1. Not more

than 10 percent of the total connected load of any of the end-use metering categories in Sections C409.3.1

through C409.3.6 is permitted to be excluded from that end-use data collection. Not more than 10 percent of the

total connected load of any of the end-use metering categories in Sections C409.3.1 through C409.3.6 is

permitted to consist of loads not part of that category. Multiple meters may be used for any end-use category,

provided that the data acquisition system totals all of the energy used by that category. Full-floor tenant space

submetering data shall be provided to the tenant in accordance with Section C409.7, and the data shall not be

required to be included in other end-use categories.

Exceptions:

1. HVAC and service water heating equipment serving only an individual dwelling unit or sleeping unit

does not require end-use metering.

2. Separate metering is not required for fire pumps, stairwell pressurization fans or other life safety

systems that operate only during testing or emergency.

3. End use metering is not required for individual tenant spaces not exceeding 2,500 square feet in floor

area when a dedicated source meter meeting the requirements of Section C409.4.1 is provided for the

tenant space.

4. Healthcare facilities with loads in excess of 150 kVA are permitted to have submetering that measures

electrical energy usage in accordance with the normal and essential electrical systems except that

CE-132 2018 Washington State Energy Code

submetering is required for the following load categories:

4.1. HVAC system energy use in accordance with the requirements of Section C409.3.1.

4.2. Service water heating energy use in accordance with the requirements of Section C409.3.2.

4.3. Process load system energy in accordance with the requirements of Section C409.3.5 for each

significant facility not used in direct patient care, including but not limited to, food service, laundry

and sterile processing facilities, where the total connected load of the facility exceeds 100 kVA.

5. End-use metering is not required for electrical circuits serving only Iand guest suites within Group R-1

occupancies. This exception does not apply to common areas or to equipment serving multiple sleeping

rooms.

C409.3.1 HVAC system energy use. This category shall include all energy including electrical, gas, liquid

fuel, district steam and district chilled water that is used by boilers, chillers, pumps, fans and other equipment

used to provide space heating, space cooling, dehumidification and ventilation to the building, but not

including energy that serves process loads, service water heating or miscellaneous loads as defined in

Section C409.3. Multiple HVAC energy sources, such as gas, electric and steam, are not required to be

summed together.

Exceptions:

1. 120 volt equipment.

2. An HVAC branch circuit where the total MCA of equipment served equates to less than 10 kVA.

3. Individual fans or pumps that are not on a variable frequency drive.

C409.3.2 Service water heating energy use. This category shall include all energy used for heating of

domestic and service hot water, but not energy used for space heating.

Exception: Service water heating energy use less than 50 kVA does not require end-use metering.

C409.3.3 Lighting system energy use. This category shall include all energy used by interior and exterior

lighting, including lighting in parking structures and lots, but not including plug-in task lighting.

C409.3.4 Electric vehicle charging energy use. This category shall include all energy used for electrical

vehicle charging. For buildings exempt from data collection systems, the data from these meters is permitted

to either be stored locally using a manual totalizing meter or other means at the meter or fed into a central

data collection system.

C409.3.5 Plug load system energy use. This category shall include all energy used by appliances,

computers, plug-in task lighting, and other equipment or equipment covered by other end-use metering

categories listed in Section C409.3. In a building where the main service is 480/277 volt, each 208/120 volt

panel is permitted to be assumed to serve only plug load for the purpose of Section C409, unless it serves

nonresidential refrigeration or cooking equipment.

Exception: Where the total connected load of all plug load circuits is less than 50 kVA end-use metering is

not required.

C409.3.6 Process load system energy use. This category shall include all energy used by any non-building

process load, including but not limited to nonresidential refrigeration and cooking equipment, laundry

equipment, industrial equipment and stage lighting.

Exception: Where the process load energy use is less than 50 kVA, end-use metering is not required.

C409.3.7 Full-floor tenant space electrical submetering. In a multi-tenant building where more than 90

percent of the leasable area of a floor is occupied by a single tenant, an electrical energy use display shall be

provided to the tenant in accordance with the requirements of Section C409.4.3. Electrical loads from areas

outside of the tenant space or from equipment that serves areas outside of the tenant space shall not be

included in the tenant space submetering. A single display is permitted to serve multiple floors occupied by

the same tenant.

C409.4 Measurement devices, data acquisition system and energy display.

C409.4.1 Meters. Meters and other measurement devices required by this section shall have local displays or

be configured to automatically communicate energy data to a data acquisition system. Source meters may be

any digital-type meters. Current sensors or flow meters are allowed for end use metering, provided that they

have an accuracy of .+/- 5%. All required metering systems and equipment shall provide at least hourly data

that is fully integrated into the data acquisition and display system per the requirements of Section C409.

2018 Washington State Energy Code CE-133

C409.4.2 Data acquisition system. The data acquisition system shall store the data from the required meters

and other sensing devices in a single database for a minimum of 36 months. For each energy supply and end

use category required by C409.2 and C409.3, it shall provide real-time energy consumption data and logged

data for any hour, day, month or year.

C409.4.3 Energy display. For each building subject to Section C409.2 and C409.3, either a visible display in

a location with ready access, or a single web page or other electronic document available for access to

building management or to a third-party energy data analysis service shall be provided in the building

available for access to building operation and management personnel. The display shall graphically provide

the current energy consumption rate for each whole building energy source, plus each end use category, as

well as the total and peak values for any day, week, month and year.

The display shall graphically provide the current energy consumption rate for each whole building energy

source, plus each end-use category, as well as the total and peak values for any day, week, month and year.

C409.4.4 Commissioning. Energy metering and energy consumption management systems shall be

commissioned in accordance with Section C408.

C409.5 Metering for existing buildings.

C409.5.1 Existing buildings that were constructed subject to the requirements of this section. Where

new or replacement systems or equipment are installed in an existing building that was constructed subject to

the requirements of this section, metering shall be provided for such new or replacement systems or

equipment so that their energy use is included in the corresponding end-use category defined in Section

C409.3. This includes systems or equipment added in conjunction with additions or alterations to existing

buildings.

C409.5.1.1 Small existing buildings. Metering and data acquisition systems shall be provided for additions

over 25,000 square feet to buildings that were constructed subject to the requirements of this section, in

accordance with the requirements of Sections C409.2 and C409.3.

SECTION C410

REFRIGERATION SYSTEM REQUIREMENTS

C410.1 General. Walk-in coolers, walk-in freezers, refrigerated warehouse coolers, refrigerated warehouse

freezers, and refrigerated display cases shall comply with this Section.

Refrigerated warehouse coolers and refrigerated warehouse freezers shall comply with Section C402. Section

C402.1.5, Component performance alternative, may be used if granted prior approval by the jurisdiction

C410.1.1 Refrigeration equipment performance. Refrigeration equipment shall have an energy use in

kWh/day not greater than the values of Tables C410.1.1(1) and C410.1.1(2) when tested and rated in

accordance with AHRI Standard 1200. The energy use shall be verified through certification under an

approved certification program or, where a certification program does not exist, the energy use shall be

supported by data furnished by the equipment manufacturer.

TABLE C410.1.1(1)

MINIMUM EFFICIENCY REQUIREMENTS: COMMERCIAL REFRIGERATION

EQUIPMENT TYPE

APPLICATION

ENERGY USE LIMITS

(kWh per day)

TEST

PROCEDURE

Refrigerator with solid doors

Holding Temperature

0.10 x V + 2.04

AHRI 1200

Refrigerator with transparent doors

0.12 x V + 3.34

Freezers with solid doors

0.40 x V + 1.38

Freezers with transparent doors

0.75 x V + 4.10

Refrigerator/freezers with solid doors

The greater of 0.12 x V + 3.34 or 0.70

Commercial refrigerators

Pulldown

0.126 x V + 3.51

a. V = Volume of the chiller for frozen compartment as defined in AHAM-HRF-1.

CE-134 2018 Washington State Energy Code

TABLE C410.1.1(2)

MINIMUM EFFICIENCY REQUIREMENTS: COMMERCIAL REFRIGERATORS AND FREEZERS

EQUIPMENT TYPE

ENERGY USE LIMITS

(kWh per day)

a,b

TEST

PROCEDURE

Equipment Class

Family Code

Operating

Mode

Rating

Temperature

VOP.RC.M

Vertical open

Remote

condensing

Medium

0.82 x TDA + 4.07

SVO.RC.M

Semivertical

open

Remote

condensing

Medium

0.83 x TDA + 3.18

HZO.RC.M

Horizontal

open

Remote

condensing

Medium

0.35 x TDA + 2.88

VOP.RC.L

Vertical open

Remote

condensing

Low

2.27 x TDA + 6.85

AHRI 1200

HZO.RC.L

Horizontal

open

Remote

condensing

Low

0.57 x TDA + 6.88

VCT.RC.M

Vertical

transparent

door

Remote

condensing

Medium

0.22 x TDA + 1.95

VCT.RC.L

Vertical

transparent

door

Remote

condensing

Low

0.56 x TDA + 2.61

SOC.RC.M

Service over

counter

Remote

condensing

Medium

0.51 x TDA + 0.11

VOP.SC.M

Vertical open

Self-contained

Medium

1.74 x TDA + 4.71

SVO.SC.M

Semivertical

open

Self-contained

Medium

1.73 x TDA + 4.59

HZO.SC.M

Horizontal

open

Self-contained

Medium

0.77 x TDA + 5.55

HZO.SC.L

Horizontal

open

Self-contained

Low

1.92 x TDA + 7.08

VCT.SC.I

Vertical

transparent

door

Self-contained

Ice cream

0.67 x TDA + 3.29

VCS.SC.I

Vertical solid

door

Self-contained

Ice cream

0.38 x V + 0.88

HCT.SC.I

Horizontal

transparent

door

Self-contained

Ice cream

0.56 x TDA + 0.43

AHRI 1200

SVO.RC.L

Semivertical

open

Remote

condensing

Low

2.27 x TDA + 6.85

VOP.RC.I

Vertical open

Remote

condensing

Ice cream

2.89 x TDA + 8.7

SVO.RC.I

Semivertical

open

Remote

condensing

Ice cream

2.89 x TDA + 8.7

HZO.RC.I

Horizontal

open

Remote

condensing

Ice cream

0.72 x TDA + 8.74

VCT.RC.I

Vertical

transparent

door

Remote

condensing

Ice cream

0.66 x TDA + 3.05

HCT.RC.M

Horizontal

transparent

door

Remote

condensing

Medium

0.16 x TDA + 0.13

HCT.RC.L

Horizontal

transparent

door

Remote

condensing

Low

0.34 x TDA + 0.26

HCT.RC.I

Horizontal

transparent

door

Remote

condensing

Ice cream

0.4 x TDA + 0.31

VCS.RC.M

Vertical solid

door

Remote

condensing

Medium

0.11 x V + 0.26

VCS.RC.L

Vertical solid

door

Remote

condensing

Low

0.23 x V + 0.54

2018 Washington State Energy Code CE-135

TABLE C410.1.1(2) (continued)

MINIMUM EFFICIENCY REQUIREMENTS: COMMERCIAL REFRIGERATORS AND FREEZERS

EQUIPMENT TYPE

ENERGY USE LIMITS

(kWh per day)

a,b

TEST

PROCEDURE

Equipment Class

Family Code

Operating

Mode

Rating

Temperature

VCS.RC.I

Vertical solid

door

Remote

condensing

Ice cream

0.27 x V + 0.63

HCS.RC.M

Horizontal solid

door

Remote

condensing

Medium

0.11 x V + 0.26

HCS.RC.L

Horizontal solid

door

Remote

condensing

Low

0.23 x V + 0.54

HCS.RC.I

Horizontal solid

door

Remote

condensing

Ice cream

0.27 x V + 0.63

SOC.RC.L

Service over

counter

Remote

condensing

Low

1.08 x TDA + 0.22

SOC.RC.I

Service over

counter

Remote

condensing

Ice cream

1.26 x TDA + 0.26

VOP.SC.L

Vertical open

Self-contained

Low

4.37 x TDA + 11.82

VOP.SC.I

Vertical open

Self-contained

Ice cream

5.55 x TDA + 15.02

SVO.SC.L

Semivertical

open

Self-contained

Low

4.34 x TDA + 11.51

SVO.SC.I

Semivertical

open

Self-contained

Ice cream

5.52 x TDA + 14.63

AHRI 1200

HZO.SC.I

Horizontal

open

Self-contained

Ice cream

2.44 x TDA + 9.0

SOC.SC.I

Service over

counter

Self-contained

Ice cream

1.76 x TDA + 0.36

HCS.SC.I

Horizontal solid

door

Self-contained

Ice cream

0.38 x V + 0.88

a V = Volume of the case, as measured in accordance with Appendix C of AHRI 1200.

b TDA = Total display area of the case, as measured in accordance with Appendix D of AHRI 1200.

c Equipment class designations consist of a combination [(in sequential order separated by periods (AAA).(BB).(C))] of:

(AAA) An equipment family code where:

VOP = Vertical open

SVO = Semi-vertical open

HZO = Horizontal open

VCT = Vertical transparent doors

VCS = Vertical solid doors

HCT = Horizontal transparent doors

HCS = Horizontal solid doors

SOC = Service over counter

(BB) An operating mode code:

RC = Remote condensing

SC = Self-contained

M = Medium temperature (38°F)

L = Low temperature (0°F)

I = Ice cream temperature (15°F)

For example, "VOP.RC.M" refers to the "vertical-open, remote-condensing, medium-temperature" equipment class.

C410.2 Walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse

freezers. Refrigerated warehouse coolers, refrigerated warehouse freezers, and all walk-in coolers and walk-in

freezers including site assembled, site constructed and prefabricated units shall comply with the following:

1. Automatic door-closers shall be provided that fully close walk-in doors that have been closed to within 1

inch (25 mm) of full closure.

Exception: Automatic closers are not required for doors more than 45 inches (1143 mm) in width or

more than 7 feet (2134 mm) in height.

2. Doorways shall be provided with strip doors, curtains, spring-hinged doors or other method of minimizing

infiltration when doors are open.

3. Walk-in coolers and refrigerated warehouse coolers shall be provided with wall, ceiling, and door

insulation of not less than R-25 or have wall, ceiling and door assembly U-factors no greater than U-0.039.

CE-136 2018 Washington State Energy Code

Walk-in freezers and refrigerated warehouse freezers shall be provided with wall, ceiling and door

insulation of not less than R-32 or have wall, ceiling and door assembly U-factors no greater than U-0.030.

Exception: Insulation is not required for glazed portions of doors or at structural members associated

with the walls, ceiling or door frame.

4. The floor of walk-in coolers shall be provided with floor insulation of not less than R-25 or have a floor

assembly U-factor no greater than U-0.040. The floor of walk-in freezers shall be provided with floor

insulation of not less than R-28 or have a floor assembly U-factor no greater than U-0.035.

Exception: Insulation is not required in the floor of a walk-in cooler that is mounted directly on a slab

on grade.

5. Transparent fixed windows and reach-in doors for walk-in freezers and windows in walk-in freezer doors

shall be provided with triple-pane glass, with the interstitial spaces filled with inert gas, or be provided with

heat-reflective treated glass.

6. Transparent fixed windows and reach-in doors for walk-in coolers and windows for walk-in cooler doors

shall be provided with double-pane or triple-pane glass, with interstitial spaces filled with inert gas, or be

provided with heat-reflective treated glass.

7. Evaporator fan motors that are less than 1 hp (0.746 kW) and less than 460 volts shall be provided with

electronically commutated motors, brushless direct-current motors, or 3-phase motors.

8. Condenser fan motors that are less than 1 hp (0.746 kW) shall use electronically commutated motors,

permanent split capacitor-type motors or 3-phase motors.

9. Antisweat heaters that are not provided with antisweat heater controls shall have a total door rail, glass

and frame heater power draw of not greater than 7.1 W/ft

(76 W/m2) of door opening for walk-in freezers

and not greater than 3.0 W/ft2 (32 W/m2) of door opening for walk-in coolers.

10. Where antisweat heater controls are provided, they shall be capable of reducing the energy use of the

antisweat heater as a function of the relative humidity in the air outside the door or to the condensation on

the inner glass pane.

11. Lights in walk-in coolers, walk-in freezers, refrigerated warehouse coolers and refrigerated warehouse

freezers shall either be provided with light sources with an efficacy of not less than 40 lumens per watt,

including ballast losses, or shall be provided with a device that turns off the lights within 15 minutes of

when the walk-in cooler or walk-in freezer space is not occupied.

C410.2.1 Performance standards. Site-assembled and site-constructed walk-in coolers and walk-in

freezers shall meet the requirements of Tables C410.2.1.1(1), C410.2.1.1(2) and C410.2.1.1(3).

TABLE C410.2.1.1(1)

WALK-IN COOLER AND FREEZER DISPLAY DOORS EFFICIENCY REQUIREMENTS

Class Description

Class

Maximum Energy Consumption (kWh/day)

Display Door, Medium Temperature

DD, M

0.04 x A

+ 0.41

Display Door, Low Temperature

DD, L

0.15 x A

+ 0.29

a. A

is the surface area of the display door

TABLE C410.2.1.1(2)

WALK-IN COOLER AND FREEZER NON-DISPLAY DOORS EFFICIENCY REQUIREMENTS

Class Description

Class

Maximum Energy Consumption (kWh/day)

Passage Door, Medium Temperature

PD, M

0.05 x A

+ 1.7

Passage Door, Low Temperature

PD, L

0.14 x A

+ 4.8

Freight Door, Medium Temperature

FD, M

0.04 x A

+ 1.9

Freight Door, Low Temperature

FD, L

0.12 x A

+ 5.6

a. A

is the surface area of the display door

2018 Washington State Energy Code CE-137

TABLE C410.2.1.1(3)

WALK-IN COOLER AND FREEZER REFRIGERATION SYSTEMS EFFICIENCY REQUIREMENTS

Class Description

Class

Minimum Annual Walk-in Energy

Factor AWEF (Btu/hW-h)

Dedicated Condensing, Medium Temperature, Indoor

System

DC.M.I

5.61

Dedicated Condensing, Medium Temperature, Indoor

System, >9,000 Btu/h Capacity

DC.M.I,

>9,000

5.61

Dedicated Condensing, Medium Temperature, Outdoor

System

DC.MI

7.60

Dedicated Condensing, Medium Temperature, Outdoor

System, >9,000 Btu/h Capacity

DC.M.I,

>9,000

7.60

C410.2.2 Refrigerated display cases. Site-assembled or site-constructed refrigerated display cases shall

comply with the following:

1. Lighting and glass doors in refrigerated display cases shall be controlled by one of the following:

1.1. Time switch controls to turn off lights during nonbusiness hours. Timed overrides for display cases

shall turn the lights on for up to 1 hour and shall automatically time out to turn the lights off.

1.2. Motion sensor controls on each display case section that reduce lighting power by at least 50

percent within 3 minutes after the area within the sensor range is vacated.

2. Low-temperature display cases shall incorporate temperature-based defrost termination control with a

time-limit default. The defrost cycle shall terminate first on an upper temperature limit breach and

second upon a time limit breach.

3. Antisweat heater controls shall reduce the energy use of the antisweat heater as a function of the

relative humidity in the air outside the door or to the condensation on the inner glass pane.

C410.3 Refrigeration systems. Refrigerated display cases, walk-in coolers or walk-in freezers that are served

by remote compressor and remote condensers not located in a condensing unit, shall comply with Sections

C410.3.1, C410.3.2, and C403.9.2.3.

Exception: Systems where the working fluid in the refrigeration cycle goes through both subcritical and

supercritical states (transcritical) or that use ammonia refrigerant are exempt.

C410.3.1 Condensers serving refrigeration systems. Fan-powered condensers shall comply with the

following:

1. The design saturated condensing temperatures for air-cooled condensers shall not exceed the design

dry-bulb temperature plus 10°F (5.6°C) for low-temperature refrigeration systems, and the design dry-

bulb temperature plus 15°F (8°C) for medium temperature refrigeration systems where the saturated

condensing temperature for blend refrigerants shall be determined using the average of liquid and vapor

temperatures as converted from the condenser drain pressure.

2. Condenser fan motors that are less than 1 hp (0.75 kW) shall use electronically commutated motors,

permanent split-capacitor-type motors or 3-phase motors.

3. Condenser fans for air-cooled condensers, evaporatively cooled condensers, air- or water-cooled fluid

coolers or cooling towers shall reduce fan motor demand to not more than 30 percent of design wattage

at 50 percent of design air volume, and incorporate one of the following continuous variable speed fan

control approaches:

3.1. Refrigeration system condenser control for air-cooled condensers shall use variable set point

control logic to reset the condensing temperature set point in response to ambient dry-bulb

temperature.

3.2. Refrigeration system condenser control for evaporatively cooled condensers shall use variable set

point control logic to reset the condensing temperature set point in response to ambient wet-bulb

temperature.

4. Multiple fan condensers shall be controlled in unison.

5. The minimum condensing temperature set point shall be not greater than 70°F (21°C).

CE-138 2018 Washington State Energy Code

C410.3.2 Compressor systems. Refrigeration compressor systems shall comply with the following:

1. Compressors and multiple-compressor system suction groups shall include control systems that use

floating suction pressure control logic to reset the target suction pressure temperature based on the

temperature requirements of the attached refrigeration display cases or walk-ins.

Exception: Controls are not required for the following:

1. Single-compressor systems that do not have variable capacity capability.

2. Suction groups that have a design saturated suction temperature of 30°F (-1.1°C) or higher,

suction groups that comprise the high stage of a two-stage or cascade system, or suction groups

that primarily serve chillers for secondary cooling fluids.

2. Liquid subcooling shall be provided for all low-temperature compressor systems with a design cooling

capacity equal to or greater than 100,000 Btu/hr (29.3 kW) with a design-saturated suction temperature

of -10°F (-23°C) or lower. The subcooled liquid temperature shall be controlled at a maximum

temperature set point of 50°F (10°C) at the exit of the subcooler using either compressor economizer

(interstage) ports or a separate compressor suction group operating at a saturated suction temperature

of 18°F (-7.8°C) or higher.

2.1. Insulation for liquid lines with a fluid operating temperature less than 60°F (15.6°C) shall comply

with Table C403.2.10.

3. Compressors that incorporate internal or external crankcase heaters shall provide a means to cycle the

heaters off during compressor operation.

C410.4 Commissioning. Refrigeration systems shall be commissioned in accordance with Section C408.

Exception: Self-contained units.

SECTION C411

SOLAR READINESS

C411.1 General. A solar zone shall be provided on non-residential buildings that are 20 stories or less in height

above grade plane. The solar zone shall be located on the roof of the building or on another structure elsewhere

on the site. The solar zone shall be in accordance with Sections C411.2 through C411.8 and the International

Fire Code.

Exception. A solar zone is not required where the solar exposure of the building’s roof area is less than 75 percent

of that of an unshaded area, as defined in Section C411.5, in the same location, as measured by one of the

following:

1. Incident solar radiation expressed in kWh/ft

-yr using typical meteorological year (TMY) data;

2. Annual sunlight exposure expressed in cumulative hours per year using TMY data;

3. Shadow studies indicating that the roof area is more than 25 percent in shadow, on September 21 at

10am, 11am, 12pm, 1pm, and 2pm solar time.

C411.2 Minimum area. The minimum area of the solar zone shall be determined by one of the following

methods, whichever results in the smaller area:

1. 40 percent of roof area. The roof area shall be calculated as the horizontally-projected gross roof area

less the area covered by skylights, occupied roof decks and planted areas.

2. 20 percent of electrical service size. The electrical service size is the rated capacity of the total of all

electrical services to the building, and the required solar zone size shall be based upon 10 peak watts of

photovoltaic per square foot.

Exception. Subject to the approval of the code official, buildings with extensive rooftop equipment that

would make full compliance with this section impractical shall be permitted to reduce the size of the solar

zone required by Section C411.2 to the maximum practicable area.

C411.3 Contiguous area. The solar zone is permitted to be comprised of separated sub-zones. Each sub-zone

shall be at least 5 feet wide in the narrowest dimension.

C411.4 Obstructions. The solar zone shall be free of pipes, vents, ducts, HVAC equipment, skylights and other

obstructions, except those serving photovoltaic systems within the solar zone. The solar zone is permitted to be

located above any such obstructions, provided that the racking for support of the future system is installed at the

time of construction, the elevated solar zone does not shade other portions of the solar zone, and its height is

permitted by the International Building Code. Photovoltaic or solar water heating systems are permitted to be

installed within the solar zone.

2018 Washington State Energy Code CE-139

C411.5 Shading. The solar zone shall be set back from any existing or new object on the building or site that is

located south, east, or west of the solar zone a distance at least two times the object’s height above the nearest

point on the roof surface. Such objects include but are not limited to taller portions of the building itself,

parapets, chimneys, antennas, signage, rooftop equipment, trees and roof plantings. No portion of the solar

zone shall be located on a roof slope greater than 2:12 that faces within 45

degrees

of true north.

C411.6 Access. Areas contiguous to the solar zone shall provide access pathways and provisions for emergency

smoke ventilation as required by the International Fire Code.

C411.7 Structural integrity. The as-designed dead load and live load for the solar zone shall be clearly marked

on the record drawings and shall accommodate future photovoltaic system arrays at an assumed dead load of 4

pounds per square foot in addition to other required live and dead loads. A location for future inverters shall be

designated either within or adjacent to the solar zone, with a minimum area of 2 square feet for each 1000 square

feet of solar zone area, and shall accommodate an assumed dead load of 175 pounds per square foot. Where

photovoltaic systems are installed in the solar zone, structural analysis shall be based upon calculated loads, not

upon these assumed loads.

C411.8 Photovoltaic interconnection. Interconnection of the future photovoltaic system shall be provided for

at the main service panel, either ahead of the service disconnecting means or at the end of the bus opposite the

service disconnecting means, in one of the following forms:

1. A space for the mounting of a future overcurrent device, sized to accommodate the largest standard rated

overcurrent device that is less than 20 percent of the bus rating.

2. Lugs sized to accommodate conductors with an ampacity of at least 20 percent of the bus rating, to

enable the mounting of an external overcurrent device for interconnection.

The electrical construction documents shall indicate the following:

1. Solar zone boundaries and access pathways;

2. Location for future inverters and metering equipment; and

3. Route for future wiring between the photovoltaic panels and the inverter, and between the inverter and the

main service panel.

CE-140 2018 Washington State Energy Code

2018 Washington State Energy Code CE-141

CHAPTER 5

EXISTING BUILDINGS

SECTION C501

GENERAL

C501.1 Scope. The provisions of this chapter shall control the alteration, repair, addition and change of

occupancy of existing buildings and structures.

C501.2 Existing buildings. Except as specified in this chapter, this code shall not be used to require the

removal, alteration or abandonment of, nor prevent the continued use and maintenance of, an existing building

or building system lawfully in existence at the time of adoption of this code.

C501.3 Maintenance. Buildings and structures, and parts thereof, shall be maintained in a safe and sanitary

condition. Devices and systems which are required by this code shall be maintained in conformance with the

code edition under which installed. The owner or the owner's authorized agent shall be responsible for the

maintenance of buildings and structures. The requirements of this chapter shall not provide the basis for

removal or abrogation of energy conservation, fire protection and safety systems and devices in existing

structures.

C501.4 Compliance. Alterations, repairs, additions and changes of occupancy to, or relocation of, existing

buildings and structures shall comply with the provisions for alterations, repairs, additions and changes of

occupancy or relocation, respectively, in this code and in the International Building Code, International Existing

Building Code, International Fire Code, International Fuel Gas Code, International Mechanical Code, Uniform

Plumbing Code, and NFPA 70.

C501.4.1 U-factor requirements for retrofits. For existing building projects where an addition or building

envelope retrofit area is combined with existing-to-remain building areas to demonstrate compliance with this

code as a whole building, the U-factors applied to existing-to-remain envelope assemblies shall be in

accordance with record documents.

Exception: If accurate record documents are not available, U-factors for the existing envelope assemblies

may be in accordance with the edition of the Washington State Energy Code that was in effect at the time

the building was permitted, or as approved by the code official.

C501.4.2 Calculation of mechanical heating and cooling loads for retrofits. For the installation of new or

replacement mechanical equipment that serves existing building areas, design loads associated with heating,

cooling and ventilation of the existing building areas served shall be determined in accordance with Section

C403.1.2.

R-values and U-factors used to determine existing thermal envelope performance for the purpose of

calculating design loads shall be in accordance with record documents or existing conditions.

Exception: If accurate record documents are not available, R-values and U-factors used to determine

existing building thermal envelope performance may be in accordance with the edition of the Washington

State Energy Code that was in effect at the time the building was permitted, or as approved by the code

official.

C501.5 New and replacement materials. Except as otherwise required or permitted by this code, materials

permitted by the applicable code for new construction shall be used. Like materials shall be permitted for

repairs, provided no hazard to life, health or property is created. Hazardous materials shall not be used where

the code for new construction would not permit their use in buildings of similar occupancy, purpose and location.

C501.6 Historic buildings. The building official may modify the specific requirements of this code for historic

buildings and require alternate provisions which will result in a reasonable degree of energy efficiency. This

modification may be allowed for those buildings or structures that are listed in the state or national register of

historic places; designated as a historic property under local or state designation law or survey; certified as a

contributing resource with a national register listed or locally designated historic district; or with an opinion or

certification that the property is eligible to be listed on the national or state registers of historic places either

CE-142 2018 Washington State Energy Code

individually or as a contributing building to a historic district by the state historic preservation officer or the

keeper of the national register of historic places.

C501.7 Commissioning. Existing building systems shall be commissioned in accordance with Section C408.

For the purposes of meeting the commissioning thresholds in Section C408.1, only the new and altered system

capacities are considered when determining whether the project is exempt from some portion of the

commissioning process.

SECTION C502

ADDITIONS

C502.1 General. Additions to an existing building, building system or portion thereof shall conform to the

provisions of this code as they relate to new construction without requiring the unaltered portion of the existing

building or building system to comply with this code. Additions shall not create an unsafe or hazardous condition

or overload existing building systems. An addition shall be deemed to comply with this code if the addition alone

complies or if the existing building and addition comply with this code as a single building. Additions shall

comply with Sections C402, C403, C404, C405, C406, C409.5, C410 and C502.2.

C502.2 Prescriptive compliance. Additions shall comply with Sections C502.2.1 through C502.2.6.2.

C502.2.1 Vertical fenestration. Additions with vertical fenestration that results in a total building vertical

fenestration area less than or equal to that specified in Section C402.4.1 shall comply with Section C402.4.

Additions with vertical fenestration that results in a total building vertical fenestration area greater than that

specified in Section C402.4.1 shall comply with one of the following:

1. Component performance alternative with target area adjustment per Section C402.1.5 for the addition

area of the building only.

2. Existing building and addition area are combined to demonstrate compliance with the component

performance alternative for the whole building.

3. Total building performance in accordance with Section C407 for the addition area of the building only.

4. Total building performance for the whole building.

C502.2.2 Skylight area. Additions with skylights that result in a total building skylight area less than or equal

to that specified in Section C402.4.1 shall comply with Section C402.4. Additions with skylights that result in a

total building skylight area greater than that specified in Section C402.4.1 shall comply with one of the

following:

1. Vertical fenestration alternate per Section C402.4.1.1 or C402.4.1.3 for the addition area of the building

only

2. Component performance alternative with the target area adjustment per Section C402.1.5 for the

addition area of the building only.

3. Existing building and addition area combined to demonstrate compliance with the component

performance alternative for the whole building.

4. Total building performance in accordance with Section C407 for the addition area of the building only.

5. Total building performance for the whole building.

C502.2.3 Building mechanical systems. New mechanical systems and equipment serving the building

heating, cooling or ventilation needs, that are part of the addition, shall comply with Section C403.

C502.2.4 Service water heating systems. New service water-heating equipment, controls and service water

heating piping shall comply with Section C404.

C502.2.5 Pools and permanent spas. New pools and permanent spas shall comply with Section C404.11.

C502.2.6 Lighting and power systems. New lighting systems that are installed as part of the addition shall

comply with Section C405.

C502.2.6.1 Interior lighting power. The total interior lighting power for the addition shall comply with

Section C405.4.2 for the addition alone, or the existing building and the addition shall comply as a single

building.

C502.2.6.2 Exterior lighting power. The total exterior lighting power for the addition shall comply with

Section C405.5.1 for the addition alone, or the existing building and the addition shall comply as a single

building.

2018 Washington State Energy Code CE-143

C502.2.7 Refrigeration systems. New refrigerated spaces and refrigeration equipment shall comply with

Section C410.

SECTION C503

ALTERATIONS

C503.1 General. Alterations to any building or structure shall comply with the requirements of Section C503 and

the code for new construction. Alterations to an existing building, building system or portion thereof shall

conform to the provisions of this code as they relate to new construction without requiring the unaltered portions

of the existing building or building system to comply with this code. Alterations shall be such that the existing

building or structure is no less conforming to the provisions of this code than the existing building or structure

was prior to the alteration.

Exception: The following alterations need not comply with the requirements for new construction provided the

energy use of the building is not increased:

1. Storm windows installed over existing fenestration.

2. Surface applied window film installed on existing single pane fenestration assemblies to reduce solar

heat gain provided the code does not require the glazing fenestration to be replaced.

3. Existing ceiling, wall or floor cavities exposed during construction provided that these cavities are

insulated to full depth with insulation having a minimum nominal value of R-3.0 per inch installed per

Section C402.

4. Construction where the existing roof, wall or floor cavity is not exposed.

5. Roof recover.

6. Air barriers shall not be required for roof recover and roof replacement where the alterations or

renovations to the building do not include alterations, renovations or repairs to the remainder of the

building envelope.

7. Replacement of existing doors that separate conditioned space from the exterior shall not require the

installation of a vestibule or revolving door, provided however that an existing vestibule that separates a

conditioned space from the exterior shall not be removed.

C503.2 Change in space conditioning. Any low energy space in accordance with Section C402.1.1.1 that is

altered to become conditioned space or semi-heated space shall be brought into full compliance with this code.

Any semi-heated space in accordance with Section C402.1.1.2 that is altered to become conditioned space

shall be brought into full compliance with this code.

For buildings with more than one space conditioning category, the interior partition walls, ceilings, floors and

fenestration that separate space conditioning areas shall comply with the thermal envelope requirements per the

area with the highest level of space conditioning.

A change in space conditioning project shall be deemed to comply with this code if the project area alone

complies or if the existing building and the project area combined comply with this code as a whole building.

Exception: Buildings or spaces that were permitted prior to the 2009 WSEC, or were originally permitted as

unconditioned, may comply with this section as follows:

1. Where the component performance alternative in Section C402.1.5 is used to demonstrate

compliance with this section, the Proposed Total UA is allowed to be up to 110 percent of the

Allowable Total UA. This exception may be applied to the project area alone, or to the existing

building and project area combined as a whole building.

2. Where total building performance in Section C407 is used to demonstrate compliance with this

section, the total annual carbon emissions from energy consumption of the proposed design is

allowed to be up to 110 percent of the annual carbon emissions from energy consumption allowed by

Section C407.3. This exception may be applied to the project area alone, or to the existing building

and project area combined as a whole building.

C503.3 Building envelope. New building envelope assemblies that are part of the alteration shall comply with

Sections C402.1 through C402.5 as applicable.

Exception: Air leakage testing is not required for alterations and repairs, unless the project includes a change

in space conditioning according to Section C503.2 or a change of occupancy or use according to Section

C505.1.

CE-144 2018 Washington State Energy Code

C503.3.1 Roof replacement. Roof replacements shall comply with Table C402.1.3 or C402.1.4 where the

existing roof assembly is part of the building thermal envelope and contains insulation entirely above the roof

deck.

C503.3.2 Vertical fenestration. The addition of vertical fenestration that results in a total building vertical

fenestration area less than or equal to that specified in Section C402.4.1 shall comply with Section C402.4.

Alterations that result in a total building vertical fenestration area greater than specified in Section C402.4.1

shall comply with one of the following:

1. Vertical fenestration alternate in accordance with Section C402.4.1.3 for the new vertical fenestration

added.

2. Vertical fenestration alternate in accordance with Section C402.4.1.1 for the area adjacent to the new

vertical fenestration added.

3. Existing building and alternation area are combined to demonstrate compliance with the component

performance alternative with target area adjustment in accordance with Section C402.1.5 for the whole

building. The Proposed Total UA is allowed to be up to 110 percent of the Allowed Total UA.

4. Total building performance in accordance with Section C407 for the whole building. The total annual

carbon emissions from energy consumption of the proposed design is allowed to be up to 110 percent

of the annual carbon emissions from energy consumption allowed in accordance with Section C407.3.

Exception: Additional envelope upgrades are included in the project so the addition of vertical fenestration

does not cause a reduction in overall building energy efficiency, as approved by the code official.

C503.3.2.1 Application to replacement fenestration products. Where some or all of an existing

fenestration unit is replaced with a new fenestration product, including sash and glazing, the replacement

fenestration unit shall meet the applicable requirements for U-factor and SHGC in Table C402.4.

Exception: An area-weighted average of the U-factor of replacement fenestration products being installed

in the building for each fenestration product category listed in Table C402.4 shall be permitted to satisfy

the U-factor requirements for each fenestration product category listed in Table C402.4. Individual

fenestration products from different product categories listed in Table C402.4 shall not be combined in

calculating the area-weighted average U-factor.

C503.3.3 Skylight area. The addition of skylights that results in a total building skylight area less than or

equal to that specified in Section C402.4.1 shall comply with Section C402.4.

The addition of skylights that results in a total building skylight area greater than that specified in Section

C402.4.1 shall comply with one of the following:

1. Existing building and alteration area are combined to demonstrate compliance with the component

performance alternative with target area adjustment in accordance with Section C402.1.5 for the whole

building. The Proposed Total UA is allowed to be up to 110 percent of the Allowed Total UA.

2. Total building performance in accordance with Section C407 for the whole building. The total annual

carbon emissions from energy consumption of the proposed design is allowed to be up to 110 percent

of the annual carbon emissions from energy consumption allowed in accordance with Section C407.3.

Exception: Additional envelope upgrades are included in the project so the addition of skylights does not

cause a reduction in overall building energy efficiency, as approved by the code official.

C503.4 Mechanical systems. Those parts of systems which are altered or replaced shall comply with Section

C403. Additions or alterations shall not be made to an existing mechanical system that will cause the existing

mechanical system to become out of compliance.

Exceptions:

1. Existing mechanical systems which are altered or where parts of the system are replaced are not

required to be modified to comply with Section C403.3.5 as long as mechanical cooling capacity is not

added to a system that did not have cooling capacity prior to the alteration.

2. Alternate mechanical system designs that are not in full compliance with this code may be approved

when the code official determines that existing building constraints including, but not limited to, available

mechanical space, limitations of the existing structure, or proximity to adjacent air intakes or exhausts

make full compliance impractical. Alternate designs shall include additional energy saving strategies not

prescriptively required by this code for the scope of the project including, but not limited to, demand

control ventilation, energy recovery, or increased mechanical cooling or heating equipment efficiency

above that required by Tables C403.3.2(1) through C403.3.2(12).

2018 Washington State Energy Code CE-145

3. Only those components of existing HVAC systems that are altered or replaced shall be required to meet

the requirements of Section C403.8.1, Allowable fan motor horsepower. Components replaced or

altered shall not exceed the fan power limitation pressure drop adjustment values in Table C403.8.1(2)

at design conditions. Section C403.8.1 does not require the removal and replacement of existing system

ductwork.

C503.4.1 New mechanical systems. All new mechanical systems in existing buildings, including packaged

unitary equipment and packaged split systems, shall comply with Section C403.

C503.4.2 Addition of cooling capacity. Where mechanical cooling is added to a space that was not

previously cooled, the mechanical system shall comply with either Section C403.3.5 or C403.5.

Exceptions:

1. Qualifying small equipment: Economizers are not required for cooling units and split systems serving

one zone with a total cooling capacity rated in accordance with Section C403.3.2 of less than 33,000

Btu/h (hereafter referred to as qualifying small systems) provided that these are high-efficiency

cooling equipment with SEER and EER values more than 15 percent higher than minimum

efficiencies listed in Tables C403.3.2 (1) through (3), in the appropriate size category, using the same

test procedures. Equipment shall be listed in the appropriate certification program to qualify for this

exception. The total capacity of all qualifying small equipment without economizers shall not exceed

72,000 Btu/h per building, or 5 percent of the building total air economizer capacity, whichever is

greater.

Notes and exclusions for Exception 1:

1.1. The portion of the equipment serving Group R occupancies is not included in determining the

total capacity of all units without economizers in a building.

1.2. Redundant units are not counted in the capacity limitations.

1.3. This exception shall not be used for the initial tenant improvement of a shell-and-core

building or space, or for total building performance.in accordance with Section C407

1.4. This exception shall not be used for unitary cooling equipment installed outdoors or in a

mechanical room adjacent to the outdoors

2. Chilled water terminal units connected to systems with chilled water generation equipment with IPLV

values more than 25 percent higher than minimum part load equipment efficiencies listed in Table

C403.3.2(7), in the appropriate size category, using the same test procedures. Equipment shall be

listed in the appropriate certification program to qualify for this exception. The total capacity of all

systems without economizers shall not exceed 480,000 Btu/h per building, or 20 percent of the

building total air economizer capacity, whichever is greater.

Notes and exclusions for Exception 1:

2.1. The portion of the equipment serving Group R occupancy is not included in determining the

total capacity of all units without economizers in a building.

2.2. This exception shall not be used for the initial tenant improvement of a shell-and-core

building or space, or for total building performance in accordance with Section C407.

C503.4.3 Alterations or replacement of existing cooling systems. Alterations to, or replacement of,

existing mechanical cooling systems shall not decrease the building total economizer capacity unless the

system complies with either Section C403.3.5 or C403.5. System alterations or replacement shall comply with

Table C503.4 when the individual cooling unit capacity and the building total capacity of all cooling equipment

without economizer do not comply with Sections C403.3.5 or C403.5.

CE-146 2018 Washington State Energy Code

TABLE C503.4

ECONOMIZER COMPLIANCE OPTIONS FOR MECHANICAL ALTERATIONS

Option A

Option B

(alternate to A)

Option C

(alternate to A)

Option D

(alternate to A)

Unit Type

Any alteration with

new or

replacement

equipment

Replacement unit of

the same type

with the same or

smaller output

capacity

Replacement unit of

the same type

with a larger output

capacity

New equipment

added to existing

system or

replacement unit of a

different type

1. Packaged

Units

Efficiency: min.

Economizer:

C403.5

Efficiency: min.

Economizer: C403.5

Efficiency: min.

Economizer: CC403.5

Efficiency: min.

Economizer: C403.5

2. Split Systems

Efficiency: min.

Economizer:

C403.5

For units ≤ 60,000

Btuh, comply with two

of two measures:

1. Efficiency: + 10%

2. Economizer: shall

not decrease

existing economizer

capability

For all other capacities:

Efficiency: min.

Economizer: C403.5

For units ≤ 60,000 Btuh

replacing unit installed

prior to 1991, comply

with at least one of two

measures:

1. Efficiency: + 10%

2. Economizer: 50%

For all other capacities:

Efficiency: min.

Economizer: C403.5

Efficiency: min.

Economizer: C403.5

3. Water Source

Heat Pump

Efficiency: min.

Economizer:

C403.5

For units ≤72,000 Btuh,

comply with at least two

of three measures:

1. Efficiency: + 10%

2. Flow control valve

3. Economizer: 50%

For all other capacities:

Efficiency: min.

Economizer: C403.5

For units ≤72,000 Btuh,

comply with at least two

of three measures:

1. Efficiency: + 10%

2. Flow control valve

3. Economizer: 50%

(except for certain

pre-1991 systems

)

For all other capacities:

Efficiency: min.

Economizer: C403.5

Efficiency: min.

Economizer: C403.5

(except for certain

pre-1991 systems

)

4. Water

Economizer

using Air-Cooled

Heat Rejection

Equipment (Dry

Cooler)

Efficiency: min.

Economizer:

C403.5

Efficiency: +5%

Economizer: shall not

decrease existing

economizer capacity

Efficiency: min.

Economizer: C403.5

Efficiency: min.

Economizer: C403.5

5. Air-Handling

Unit (including

fan coil units)

where the

system has an

air-cooled chiller

Efficiency: min.

Economizer:

C403.5

Economizer: shall not

decrease existing

economizer capacity

Efficiency: min.

Economizer: C403.5

(except for certain

pre-1991 systems

)

Efficiency: min.

Economizer:

C403.5

(except for certain

pre-1991 systems

)

6. Air- Handling

Unit (including

fan coil units)

and Water-

cooled Process

Equipment,

where the

system has a

water-cooled

chiller

Efficiency: min.

Economizer:

C403.5

Economizer: shall not

decrease existing

economizer capacity

Efficiency: min.

Economizer: C403.5

(except for certain

pre-1991 systems

and certain 1991-

2016 systems

Efficiency: min.

Economizer: C403.5

(except for certain

pre-1991 systems

and certain 1991-

2016 systems

)

2018 Washington State Energy Code CE-147

TABLE C503.4 (continued)

ECONOMIZER COMPLIANCE OPTIONS FOR MECHANICAL ALTERATIONS

Option A

Option B

(alternate to A)

Option C

(alternate to A)

Option D

(alternate to A)

Unit Type

Any alteration with

new or

replacement

equipment

Replacement unit of

the same type

with the same or

smaller output

capacity

Replacement unit of

the same type

with a larger output

capacity

New equipment

added to existing

system or

replacement unit of a

different type

7. Cooling Tower

Efficiency: min.

Economizer:

C403.5

No requirements

Efficiency: min.

Economizer: C403.5

Efficiency: min.

Economizer: C403.5

8. Air-Cooled

Chiller

Efficiency: min.

Economizer:

C403.5

Efficiency: + 10%

Economizer: shall not

decrease existing

economizer capacity

Efficiency: Comply with

two of two measures:

1. + 10%

k,l

2. Multistage

Economizer: shall not

decrease existing

economizer capacity

Efficiency: min.

Economizer: C403.5

9. Water-Cooled

Chiller

Efficiency: min.

Economizer:

C403.5

Efficiency: Comply with

at least one of two

measures:

1. Part load IPLV +

15%

2. Plate frame heat

exchanger

Economizer: shall not

decrease existing

economizer capacity

Efficiency: Comply with

two of two measures:

1. Part load IPLV +

15%

2. Plate frame heat

exchanger

Economizer: shall not

decrease existing

economizer capacity

Efficiency: min.

Economizer: C403.5

a. Minimum equipment efficiency shall comply with Section C403.3.2 and Tables C403.3.2(1) through C403.3.2(12).

b. All separate new equipment and replacement equipment shall have air economizer complying with Section C403.5

including both the individual unit size limits and the total building capacity limits on units without economizer. It is

acceptable to comply using one of the exceptions to Section C403.5.

c. Reserved.

d. Equipment shall have a capacity-weighted average cooling system efficiency that is 5 percent better than the

requirements in Tables C403.3.2(1) and C403.3.2(2) (1.05 x values in Tables C403.3.2(1) and C403.3.2(2)).

e. Equipment shall have a capacity-weighted average cooling system efficiency that is 10 percent better than the

requirements in Tables C403.3.2(1)A and C403.3.2(2) (1.10 x values in Tables C403.3.2(1)A and C403.3.2(2)).

f. Minimum of 50 percent air economizer that is ducted in a fully enclosed path directly to every heat pump unit in each

zone, except that ducts may terminate within 12 inches of the intake to an HVAC unit provided that they are physically

fastened so that the outside air duct is directed into the unit intake. If this is an increase in the amount of outside air

supplied to this unit, the outside air supply system shall be configured to provide this additional outside air and be

equipped with economizer control.

g. Water-source heat pump systems shall have a flow control valve to eliminate flow through the heat pumps that are not in

operation and variable speed pumping control complying with Section C403.4.3 for that heat pump.

 When the total capacity of all units with flow control valves exceeds 15 percent of the total system capacity, a

variable frequency drive shall be installed on the main loop pump.

 As an alternate to this requirement, the capacity-weighted average cooling system efficiency shall be 5 percent

better than the requirements in footnote e for water-source heat pumps (i.e. a minimum of 15 percent better than

the requirements in Table C403.3.2(2) (1.15 x values in Table C403.3.2(2)).

h. Water economizer equipment shall have a capacity-weighted average cooling system efficiency that is 10 percent better

than the requirements in Tables C403.3.2(8) and C403.3.2(9) (1.10 x values in Tables C403.3.2(8) and C403.3.2(9)).

i. Air economizer is not required for systems installed with water economizer plate and frame heat exchanger complying

with previous codes between 1991 and June 2016, provided that the total fan coil load does not exceed the existing or

added capacity of the heat exchangers.

j. For water-cooled process equipment where the manufacturers specifications require colder temperatures than available

with water-side economizer, that portion of the load is exempt from the economizer requirements.

CE-148 2018 Washington State Energy Code

k. The air-cooled chiller shall have an IPLV efficiency that is a minimum of 10 percent greater than the IPLV requirements

in EER in Table C403.3.2(7)(1.10 x IPLV values in EER in Table C403.3.2(7)).

l. The air-cooled chiller shall be multistage with a minimum of two compressors.

m. The water-cooled chiller shall have full load and part load IPLV efficiency that is a minimum of 5 percent greater than the

IPLV requirements in Table C403.3.2(7) (1.05 x IPLV values in Table C403.3.2(7)).

n. The water-cooled chiller shall have an IPLV value that is a minimum of 15 percent lower than the IPLV requirements in

Table C403.3.2(7), (1.15 x IPLV values in Table C403.3.2(7)). Water-cooled centrifugal chillers designed for non-

standard conditions shall have an NPLV value that is at least 15 percent lower than the adjusted maximum NPLV rating

in kW per ton defined in Section C403.3.2.1 (1.15 x NPLV).

o. Economizer cooling shall be provided by adding a plate-frame heat exchanger on the water-side with a capacity that is a

minimum of 20% of the chiller capacity at standard AHRI rating conditions.

p. Reserved.

q. Systems installed prior to 1991 without fully utilized capacity are allowed to comply with Option B, provided that the

individual unit cooling capacity does not exceed 90,000 Btuh.

C503.4.4 Controls for cooling equipment replacement. When space cooling equipment is replaced,

controls shall comply with all requirements under Section C403.3.5 and related subsections, and Section

C403.5.1. for integrated economizer control.

C503.4.5 Cooling equipment relocation. Existing equipment currently in use may be relocated within the

same floor or same tenant space if removed and reinstalled within the same permit.

C503.5 Service hot water systems. New service hot water systems that are part of the alteration shall comply

with Section C404.

C503.6 Lighting, controlled receptacles and motors. Alterations or the addition of lighting, controlled

receptacles and motors shall comply with Sections C503.6.1 through C503.6.6.

C503.6.1 Luminaire additions and alterations. Alterations that add or replace 50 percent or more of the

luminaires in a space enclosed by walls or ceiling-height partitions, replace 50 percent or more of parking

garage luminaires, or replace 50 percent or more of the total installed wattage of exterior luminaires shall

comply with Sections C405.4 and C405.5. Where less than 50 percent of the fixtures in an interior space

enclosed by walls or ceiling-height partitions or in a parking garage are added or replaced, or less than 50

percent of the installed exterior wattage is replaced, the installed lighting wattage shall be maintained or

reduced.

C503.6.2 Rewiring and recircuiting. Where new wiring is being installed to serve added fixtures and/or

fixtures are being relocated to a new circuit, controls shall comply with Sections C405.2.1, C405.2.3,

C405.2.4, C405.2.5, and C405.2.6, and as applicable C408.3. New lighting control devices shall comply with

the requirements of Section C405.2.

C503.6.3 New or moved lighting panel. Where a new lighting panel (or a moved lighting panel) with all new

raceway and conductor wiring from the panel to the fixtures is being installed, controls shall also comply with,

in addition to the requirements of Section C503.6.2, all remaining requirements in Sections C405.2 and

C408.3.

C503.6.4 Newly-created rooms. Where new walls or ceiling-height partitions are added to an existing space

and create a new enclosed space, but the lighting fixtures are not being changed, other than being relocated,

the new enclosed space shall have controls that comply with Sections C405.2.1, C 405.2.2, C405.2.3,

C405.2.4, C405.2.5 and C408.3.

C503.6.5 Motors. Those motors which are altered or replaced shall comply with Section C405.8.

C503.6.6 Controlled receptacles. Where electric receptacles are added or replaced, controlled receptacles

shall be provided in accordance with Section C405.10.

Exceptions:

1. Where an alteration project impacts an area smaller than 5,000 square feet, controlled receptacles

are not required.

2018 Washington State Energy Code CE-149

2. Where existing systems furniture or partial-height relocatable office cubicle partitions are

reconfigured or relocated within the same area, controlled receptacles are not required in the

existing systems furniture or office cubicle partitions.

3. Where new or altered receptacles meet the exception to Section C405.10, they are not required to

be controlled receptacles or be located within 12 inches of non-controlled receptacles.

C503.7 Refrigeration systems. Those parts of systems which are altered or replaced shall comply with Section

C410. Additions or alterations shall not be made to an existing refrigerated space or system that will cause the

existing mechanical system to become out of compliance. All new refrigerated spaces or systems in existing

buildings, including refrigerated display cases, shall comply with Section C410.

SECTION C504

REPAIRS

C504.1 General. Buildings and structures, and parts thereof, shall be repaired in compliance with Section

C501.3 and this section. Work on nondamaged components that is necessary for the required repair of

damaged components shall be considered part of the repair and shall not be subject to the requirements for

alterations in this chapter. Routine maintenance required by Section C501.3, ordinary repairs exempt from

permit, and abatement of wear due to normal service conditions shall not be subject to the requirements for

repairs in this section.

C504.2 Application. For the purposes of this code, the following shall be considered repairs.

1. Glass only replacements in an existing sash and frame.

2. Roof repairs.

3. Air barriers shall not be required for roof repair where the repairs to the building do not include alterations,

renovations or repairs to the remainder of the building envelope.

4. Replacement of existing doors that separate conditioned space from the exterior shall not require the

installation of a vestibule or revolving door, provided however that an existing vestibule that separates a

conditioned space from the exterior shall not be removed.

5. Repairs where only the bulb and/or ballast within the existing luminaires in a space are replaced provided

that the replacement does not increase the installed interior lighting power.

SECTION C505

CHANGE OF OCCUPANCY OR USE

C505.1 General. Spaces undergoing a change in occupancy shall be brought up to full compliance with this

code in the following cases:

1. Any space that is converted from an F, S or U occupancy to an occupancy other than F, S or U.

2. Any space that is converted to a Group R dwelling unit or portion thereof, from another use or occupancy.

3. Any Group R dwelling unit or portion thereof permitted prior to July 1, 2002, that is converted to a

commercial use or occupancy.

Exception: Buildings or spaces that were permitted prior to the 2009 WSEC, or were originally permitted as

unconditioned, may comply with this section as follows:

1. Where the component performance alternative in Section C402.1.5 is used to demonstrate compliance

with this section, the Proposed Total UA is allowed to be up to 110 percent of the Allowable Total UA.

This exception may be applied to the project area alone, or to the existing building and project area

combined as a whole building.

2. Where total building performance in Section C407 is used to demonstrate compliance with this section,

the total annual carbon emissions from energy consumption of the proposed design is allowed to be

110 percent of the annual carbon emissions from energy consumption allowed by Section C407.3. This

exception may be applied to the project area alone, or to the existing building and project area

combined as a whole building.

Where the use in a space changes from one use in Table C405.4.2(1) or (2) to another use in Table

C405.4.2(1) or (2), the installed lighting wattage shall comply with Section C405.4.

CE-150 2018 Washington State Energy Code

2018 Washington State Energy Code CE-151

CHAPTER 6

REFERENCED STANDARDS

This chapter lists the standards that are referenced in various sections of this document. The standards are

listed herein by the promulgating agency of the standard, the standard identification, the effective date and title,

and the section or sections of this document that reference the standard. The application of the referenced

standards shall be as specified in Section 106.

AAMA

American Architectural Manufacturers Association

1827 Walden Office Square

Suite 550

Schaumburg, IL 60173-4268

Standard

Referenced

reference

in code

number

Title section number

AAMA/WDMA/CSA

101/I.S.2/A C440—17

North American Fenestration Standard/

Specifications for Windows, Doors and Unit Skylights .................. Table C402.4,

C402.4.1.1.2

AHAM

Association of Home Appliance Manufacturers

1111 19th Street, NW, Suite 402

Washington, DC 20036

Standard

Referenced

reference

in code

number

Title section number

ANSI/

AHAM RAC-1—2008

Room Air Conditioners ................................................................. Table C403.3.2(3)

AHAM HRF-1—2017

Household Refrigerators, Refrigerator-Freezers and Freezers . Table C4410.1(1)(3)

AHRI

Air Conditioning, Heating, and Refrigeration Institute

4100 North Fairfax Drive

Suite 200

Arlington, VA 22203

Standard

Referenced

reference

in code

number

Title section number

ISO/AHRI/ASHRAE

13256-1 (2017)

Water-source Heat Pumps—Testing and Rating for Performance—

Part 1: Water-to-air and Brine-to-air Heat Pumps ..................... Table C403.3.2(2)

ISO/AHRI/ASHRAE

13256-2 (2017)

Water-source Heat Pumps—Testing and Rating for Performance—

Part 2: Water-to-water and Brine-to-water Heat Pumps ............ Table C403.3.2(2)

210/240—2016

Unitary Air Conditioning and Air-source Heat Pump Equipment ... Table C403.3.2(1),

Table C403.3.2(2)

310/380—2014

Standard for Packaged Terminal Air Conditioners and Heat Pumps ................. Table

C403.3.2(3)

340/360—2015

Commercial and Industrial Unitary Air-conditioning and

Heat Pump Equipment ............................... Table C403.3.2(1), Table C403.3.2(2)

365—09

Commercial and Industrial Unitary Air-conditioning

Condensing Units ..................................... Table C403.3.2(1), Table C403.3.2(6)

390—2011

Performance Rating of Single Package Vertical Air Conditioners

and Heat Pumps ....................................................................... Table C403.3.2(3)

400—01

Liquid to Liquid Heat Exchangers with Addendum 2 ..................... Table C403.3.2(9)

440—08

Room Fan Coil ........................................................................................... C403.10.3

460—05

Performance Rating Remote Mechanical Draft Air-cooled

Refrigerant Condensers ............................................................ Table C403.3.2(8)

CE-152 2018 Washington State Energy Code

AHRI --continued

550/590—03

Water Chilling Packages Using the Vapor Compression Cycle—with

Addenda .................................................................................................. C403.3.2.1,

Table C403.3.2(7)

560—00

Absorption Water Chilling and Water-heating Packages ............... Table C403.3.2(7)

920—15

Performance Rating of DX-Dedicated

Outdoor Air System Units ........................ Table C403.3.2(11), Table C403.3.2(12)

1160—2014

Performance Rating of Heat Pump Pool Heaters ................................. Table C404.2

1200—2014

Performance Rating of Commercial Refrigerated Display Merchandisers

and Storage Cabinets ................. C410.1.1, Table C410.1.1(1) Table C410.1.1(2)

AMCA

Air Movement and Control Association International

30 West University Drive

Arlington Heights, IL 60004-1806

Standard

Referenced

reference

in code

number

Title section number

205-12

Energy Efficiency Classification for Fans .....................................C403.8.3, C406.2.3

220-08 (R2012)

Laboratory Methods of Testing Air Curtain Units ......................................... C402.5.6

500D—10

Laboratory Methods for Testing Dampers for Rating ................................ C403.7.8.3

ANSI

American National Standards Institute

25 West 43rd Street

Fourth Floor

New York, NY 10036

Standard

Referenced

reference

in code

number

Title section number

Z21.10.3/CSA 4.3—11

Gas Water Heaters, Volume III—Storage Water Heaters with Input Ratings

Above 75,000 Btu per Hour, Circulating Tank and Instantaneous ... Table C404.2

Z21.47/CSA 2.3—12

Gas-fired Central Furnaces ........................................................... Table C403.3.2(4)

Z83.8/CSA 2.6—09

Gas Unit Heaters, Gas Packaged Heaters, Gas Utility Heaters

and Gas-fired Duct Furnaces .................................................... Table C403.3.2(4)

APSP

The Association of Pool and Spa Professionals

2111 Eisenhower Avenue

Alexandria, VA 22314

Standard

Referenced

reference

in code

number

Title section number

14-2014

American National Standard for Portable Electric Spa Efficiency ................. C404.8

ASHRAE

American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.

1791 Tullie Circle, NE

Atlanta, GA 30329-2305

Standard

Referenced

reference

in code

number

Title section number

ANSI/ASHRAE/ACCA

Standard 127-2007

Method of Testing for Rating Computer and Data Processing Room Unitary Air

Conditioners ................................................................................................ C403.4.1

Standard 183—2007

Peak Cooling and Heating Load Calculations in Buildings,

Except Low-rise Residential Buildings .................................................... C403.1.2

ASHRAE—2016

ASHRAE HVAC Systems and Equipment Handbook—2004 ..................... C403..1.2

ISO/AHRI/ASHRAE

13256-1 (2011)

Water-source Heat Pumps—Testing and Rating for Performance—

Part 1: Water-to-air and Brine-to-air Heat Pumps ..................... Table C403.3.2(2)

ISO/AHRI/ASHRAE

13256-2 (2011)

Water-source Heat Pumps—Testing and Rating for Performance—

Part 2: Water-to-water and Brine-to-water Heat Pumps ............ Table C403.3.2(2)

2018 Washington State Energy Code CE-153

ASHRAE --continued

90.1—2016

Energy Standard for Buildings Except Low-rise

Residential Buildings ............................................................. . C402.1.5.1, C407.3

90.4—2016

Energy Standard for Data Centers............................................................... C403.1.3

146—2011

Testing and Rating Pool Heaters .......................................................... Table C404.2

ASME

American Society Mechanical Engineers

Two Park Avenue

New York, NY 10016-5990

Standard

Referenced

reference

in code

number

Title section number

ASME A17.1/

CSA B44—2016

Safety Code for Elevators and Escalators ................................................. C405.9.2

ASTM

ASTM International

100 Barr Harbor Drive

West Conshohocken, PA 19428-2859

Standard

Referenced

reference

in code

number

Title section number

C 90—14

Specification for Load-bearing Concrete Masonry Units .................... Table C402.1.3

C 518—17

Standard Test Method for Steady-State Thermal Transmission Properties

By Means of the Heat Flow Meter Apparatus........................... Table C403.10.1.1

C 1371—11

Standard Test Method for Determination of Emittance of Materials

Near Room Temperature Using Portable Emissometers .......... C303.1.4.1, Table

C402.1.4

D 1003—13

Standard Test Method for Haze and Luminous Transmittance of

Transparent Plastics ............................................................................ C402.4.2.2

E 283—04

Test Method for Determining the Rate of Air Leakage Through Exterior

Windows, Curtain Walls and Doors Under Specified Pressure

Differences Across the Specimen .......................................................... C402.5.8,

E779—10

Standard Test Method for Determining Air Leakage Rate

by Fan Pressurization ........................................................ C402.5.1.2, C406.11.1

CSA

Canadian Standards Association

5060 Spectrum Way

Mississauga, Ontario, Canada L4W 5N6

Standard

Referenced

reference

in code

number

Title .................................................................................................. section number

AAMA/WDMA/CSA

101/I.S.2/A440—17

North American Fenestration Standard/Specification for

Windows, Doors and Unit Skylights ............................. Table C402.4, C402.4.1.1.2

CSA B55.1—2012

Test Method for Measuring Efficiency and Pressure Loss of DWHR Units ... C404.10

CSA B55.2—2012

Drain Water Heat Recovery Units ................................................................. C404.10

CTI

Cooling Technology Institute

2611 FM 1960 West, Suite A-101

Houston, TX 77068

Standard

Referenced

reference

in code

number

Title section number

ATC 105 (00)

Acceptance Test Code for Water Cooling Tower ........................... Table C403.3.2(8)

ATC 105S—2011

Acceptance Test Code for Closed Circuit Cooling Towers ............ Table C403.3.2(8)

ATC 106—2011

Acceptance Test for Mechanical Draft Evaporative Vapor Condensers .......... Table

C403.3.2(8)

STD 201 RS(15)

Standard for Certification of Water Cooling Towers Thermal Performances ..... Table

C403.3.2(8)

CE-154 2018 Washington State Energy Code

DASMA

Door and Access Systems Manufacturers Association

1300 Sumner Avenue

Cleveland, OH 44115-2851

Standard

Referenced

reference

in code

number

Title section number

105—92 (R2004)—13

Test Method for Thermal Transmittance and Air Infiltration of Garage

Doors ........................................................................................................... C303.1.3

DOE

U.S. Department of Energy

c/o Superintendent of Documents

U.S. Government Printing Office

Washington, DC 20402-9325

Standard

Referenced

reference

in code

number

Title section number

10 CFR, Part 430—1998

Energy Conservation Program for Consumer Products:

Test Procedures and Certification and Enforcement Requirement

for Plumbing Products; and Certification and Enforcement

Requirements for Residential Appliances; Final Rule .... Table C403.3.2(4), Table

C403.3.2(5),

Table C404.2

10 CFR, Part 430, Subpart B,

Appendix N—1998

Uniform Test Method for Measuring the Energy Consumption of

Furnaces and Boilers .................................................................................... C202

10 CFR, Part 431—2004

Energy Efficiency Program for Certain Commercial and Industrial

Equipment: Test Procedures and Efficiency Standards; Final Rules ............ Table

C403.3.2(5), Table C406.2(5)

NAECA 87—(88)

National Appliance Energy Conservation Act 1987

[(Public Law 100-12 (with Amendments of 1988-P.L. 100-357)] ................. Tables

C403.3.2(1), (2), (4)

IAPMO

International Association of Plumbing and Mechanical Officials

4755 E. Philadelphia Street

Ontario, CA 91761

Standard

Referenced

reference

in code

number

Title section number

UPC—2018

Uniform Plumbing Code ...................................................................C201.3, C501.4

ICC

International Code Council, Inc.

500 New Jersey Avenue, NW

6th Floor

Washington, DC 20001

Standard

Referenced

reference

in code

number

Title section number

IBC—18

International Building Code ............. C201.3, C303.1.1, C303.2, C402.5.3, C402.5.4

Table C403.3.5, C405.2.1.5, C405.2.5, C411.4, C501.4

IEBC—18

International Existing Building Code .................................................... C201.3, 501.4

IFC—18

International Fire Code ..........................................C201.3, C411.1, C411.6, C501.4

IFGC—18

International Fuel Gas Code ..............................................................C201.3, C501.4

IMC—18

International Mechanical Code .. C106.3, C201.3, C402.5.3, C403.2.2.1, C403.2.2.2

C403.3.5, C403.3.5.1, C403.6.1, C403.6.5, C403.6.10, C403.7.1, C403.7.2,

C403.7.5, C403.7.5.1, C403.7.6, C403.7.7.3, C403.7.8, C403.7.8.4, C403.8.4,

C403.8.5.1, C403.9.2.4.2, C403.10.1.1,

Table C403.10.1.1, C403.10.1.2, Table C403.10.1.2, C403.10.2, C403.10.2.1,

C403.10.2.2, C403.12, C406.6, C408.2.2.1, C501.4

2018 Washington State Energy Code CE-155

IEEE

The Institute of Electrical and Electronic Engineers

Three Park Avenue

New York, NY 10016

Standard

Referenced

reference

in code

number

Title section number

IEEE 515.1—2012

Standard for the Testing, Design, Installation and Maintenance

of Electrical Resistance Trace Heating for Commercial Applications ....... C404.6.2

IESNA

Illuminating Engineering Society of North America

120 Wall Street, 17th Floor

New York, NY 10005-4001

Standard

Referenced

reference

in code

number

Title section number

ANSI/ASHRAE/IESNA

90.1—2016

Energy Standard for Buildings Except Low-rise Residential Buildings ... . C402.1.5.1,

C407.3

ISO

International Organization for Standardization

1, rue de Varembe, Case postale 56, CH-1211

Geneva, Switzerland

Standard

Referenced

reference

in code

number

Title section number

ISO/AHRI/ASHRAE

13256-1 (2017)

Water-source Heat Pumps—Testing and Rating for Performance—

Part 1: Water-to-air and Brine-to-air Heat Pumps ..................... Table C403.3.2(2)

ISO/AHRI/ASHRAE

13256-2 (2017)

Water-Source Heat Pumps—Testing and Rating for Performance—

Part 2: Water-to-water and Brine-to-water Heat Pumps ............ Table C403.3.2(2)

NEMA

National Electric Manufacturer’s Association

1300 North 17

Street

Suite 1753

Rosslyn, VA 22209

Standard

Referenced

reference

in code

number

Title section number

MG1—2014

Motors and Generators ...................................................................................... C202

NFRC

National Fenestration Rating Council, Inc.

6305 Ivy Lane, Suite 140

Greenbelt, MD 20770

Standard

Referenced

reference

in code

number

Title section number

100—2017

Procedure for Determining Fenestration Products U-factors—Second Edition

.....................................................................................................C303.1.2, C402.2.1

200—2017

Procedure for Determining Fenestration Product Solar Heat Gain Coefficients

and Visible Transmittance at Normal Incidence—Second Edition ........ C303.1.3,

C402.3.1.1

202—2017

Procedure for Determining Fenestration Product Visible Transmittance

at Normal Incidence ...................................................................................... C202

203—2017

Procedure for Determining Visible Transmittance of

Tubular Daylighting Devices .........................................................C202, C402.4.2

CE-156 2018 Washington State Energy Code

SMACNA

Sheet Metal and Air Conditioning Contractors National Association, Inc.

4021 Lafayette Center Drive

Chantilly, VA 20151-1209

Standard

Referenced

reference

in code

number

Title section number

SMACNA—2012

HVAC Air Duct Leakage Test Manual ..................................................... C403.10.2.3

Underwriters Laboratories

333 Pfingsten Road

Northbrook, IL 60062-2096

Standard

Referenced

reference

in code

number

Title section number

710—12

Exhaust Hoods for Commercial Cooking Equipment ....... C403.7.7.1.2, C403.7.7.1.3

727—06

Oil-fired Central Furnaces—with Revisions through April 2010 ..... Table C403.3.2(4)

731—95

Oil-fired Unit Heaters—with Revisions through April 2010 ............. Table C403.3.2(4)

US-FTC

United States-Federal Trade Commission

600 Pennsylvania Avenue NW

Washington, DC 20580

Standard

Referenced

reference

in code

number

Title section number

CFR Title 16

R-value Rule .............................................................................................. C303.1.4

(2015)

WDMA

Window and Door Manufacturers Association

1400 East Touhy Avenue, Suite 470

Des Plaines, IL 60018

Standard

Referenced

reference

in code

number

Title section number

AAMA/WDMA/CSA

101/I.S.2/A440—11

North American Fenestration Standard/Specification for

Windows, Doors and Unit Skylights .......................... Table C402.4, C402.4.1.1.2

2018 Washington State Energy Code CE-1

WASHINGTON STATE ENERGY CODE,

APPENDIX CHAPTERS

TABLE OF CONTENTS

Appendix A Default Heat Loss

Coefficients ............................ AE-3

A101 General ....................................... AE-3

A101.1 Scope .................................. AE-3

A101.2 Description .......................... AE-3

A101.3 Air Films .............................. AE-3

A101.4 R-Value of Compressed

Insulation .................................. AE-3

A101.5 Building Materials ................ AE-3

A102 Ceilings ...................................... AE-5

A102.1 Default U-Factors

for Ceilings ............................... AE-5

A102.2 Component Description ....... AE-5

A102.2.1 Vented Attic .................... AE-5

A102.2.2 Vaulted Ceiling ............... AE-5

A102.2.3 Roof Decks .................... AE-5

A102.2.4 Metal Truss Framing ...... AE-5

A102.2.5 Metal Building Roof ........ AE-7

A102.2.6 Insulation Entirely Above

Roof Deck ............................. AE-8

A103 Above Grade Walls ................. AE-12

A103.1 General .............................. AE-12

A103.2 Framing Description .......... AE-12

A103.3 Component Description ..... AE-12

A103.3.1 Single Stud Wall........... AE-12

A103.3.2 Strap Wall .................... AE-17

A103.3.3 Double Stud Wall ......... AE-17

A103.3.4 Log Wall ....................... AE-17

A103.3.5 Stress Skin Panel ........ AE-17

A103.3.6 Metal Stud Walls .......... AE-17

A103.3.7 Concrete and

Masonry Walls .................... AE-17

A104 Below Grade Walls and Slabs AE-28

A104.1 General .............................. AE-28

A104.2 Component Description ..... AE-28

A104.3 Insulation Description ........ AE-29

A105 Floors Over

Unconditioned Space ........... AE-29

A105.1 General .............................. AE-29

A105.2 Crawlspace Description ..... AE-31

A105.3 Construction Description.... AE-31

A106 On-Grade Slab Floors.............. AE-31

A106.1 General .............................. AE-31

A106.2 Component Description ..... AE-32

A106.3 Insulation Description ........ AE-32

A107 Default U-Factors for Doors ... AE-32

A107.1 Doors Without NFRC

Certification ............................ AE-32

A108 Air Infiltration ........................... AE-36

A108.1 General .............................. AE-36

Appendix B Default Internal

Load Values

and Schedules ...................... AE-37

B101 General ...................................... AE-37

B102 Default Tables of

Internal Loads ......................... AE-37

B103 Default Schedules ...................... AE-38

Appendix C Exterior Design

Conditions ............................. AE-49

Appendix D Calculation of HVAC

Total System

Performance Ratio ..................... 51

Appendix E Renewable Energy ..................... 61

Appendix F Outcome-Based

Energy Budget ............................ 63

AE-2 2018 Washington State Energy Code

Appendix A

DEFAULT HEAT LOSS COEFFICIENTS

SECTION A101

GENERAL REQUIREMENTS

A101.1 Scope. The following defaults shall apply to

Chapter 4 of both the (RE) and (CE) sections of the

WSEC. This chapter includes tables of seasonal

average heat loss coefficients for specified nominal

insulation.

A101.2 Description. These coefficients were

developed primarily from data and procedures from

the ASHRAE Fundamentals Handbook.

Coefficients not contained in this chapter may be

computed using the procedures listed in this reference

if the assumptions in the following sections are used,

along with data from the sources referenced above.

A101.3 Air films. Default R-values used for air

films shall be as follows:

R-Value Condition

0.17 All exterior surfaces

0.61 Interior horizontal surfaces,

heat flow up

0.92 Interior horizontal surfaces,

heat flow down

0.68 Interior vertical surfaces

A101.4 Compression of Insulation: Insulation

which is compressed shall be rated in accordance

with Table A101.4 or reduction in value may be

calculated in accordance with the procedures in the

ASHRAE Fundamentals Handbook.

A101.5 Building materials. Default R-values used

for building materials shall be as shown in Table

A101.5.

TABLE A101.4

R-VALUE OF FIBERGLASS BATTS COMPRESSED WITHIN VARIOUS DEPTH CAVITIES

Insulation R-Values at Standard Thickness

Rated R-Value

Standard

Thickness, Inches

26.0

22.5

19.0

15.5

12”

9.5

6.5

5.5

3.5

Nominal

Lumber

Sizes,

Inches

Actual

Depth of

Cavity,

Inches

Insulation R-Values When Installed in a Confined Cavity

Truss

26.0

—

Truss

22.5

—

Truss

19.0

—

Truss

15.5

—

Truss

12.0

—

2x12

11.25

—

2x10

9.25

—

2x8

7.25

—

2x6

5.5

—

2x4

3.5

—

2.5

—

9.8

—

1.5

—

6.3

6.0

2018 Washington State Energy Code AE-3

TABLE A101.5

DEFAULT R-VALUES FOR BUILDING MATERIALS

Material

Nominal

Size (in.)

Actual

Size (in.)

R-Value

(Heat Capacity

)

Air cavity (unventilated), between metal studs at 16 inches on center

0.79

Air cavity (unventilated), all other depths and framing materials

0.91

Airfilm, exterior surfaces

0.17

Airfilm, interior horizontal surfaces, heat flow up

0.61

Airfilm, interior horizontal surfaces, heat flow down

0.92

Airfilm, interior vertical surfaces

0.68

Brick at R-0.12/in. (face brick, 75% solid/25% core area, 130 lbs/ft

)

3.5

0.32 (5.9)

Carpet and rubber pad

1.23

Concrete at R-0.0625/in., heavyweight (144 lbs/ft

)

0.13 (HC-4.8)

0.25 (HC-9.6)

0.38 (HC-14.4)

0.50 (HC-19.2)

0.63 (HC-24.0)

0.75 (HC-28.8)

Concrete masonry units, solid grouted, lightweight (95 lbs/ft3)

0.80 (HC-11.4)

Concrete masonry units, solid grouted, normal weight (135 lbs/ft3)

0.51 (HC-13.2)

Concrete masonry units, partly grouted, lightweight (95 lbs/ft3)

1.33 (HC-6.7)

Concrete masonry units, partly grouted, normal weight (135 lbs/ft3)

0.82 (HC-9.0)

Concrete masonry units, solid grouted, lightweight (95 lbs/ft3)

1.05 (HC-15.5)

Concrete masonry units, solid grouted, normal weight (135 lbs/ft3)

0.69 (HC-17.9)

Concrete masonry units, partly grouted, lightweight (95 lbs/ft3)

1.44 (HC-9.6)

Concrete masonry units, partly grouted, normal weight (135 lbs/ft3)

0.98 (HC-12.0)

Concrete masonry units, solid grouted, lightweight (95 lbs/ft3)

1.30 (HC-19.7)

Concrete masonry units, solid grouted, normal weight (135 lbs/ft3)

0.87 (HC-22.6)

Concrete masonry units, partly grouted, lightweight (95 lbs/ft3)

1.61 (HC-11.9)

Concrete masonry units, partly grouted, normal weight (135 lbs/ft3)

1.11 (HC-14.8)

Concrete masonry units, solid grouted, lightweight (95 lbs/ft3)

1.53 (HC-23.9)

Concrete masonry units, solid grouted, normal weight (135 lbs/ft3)

1.06 (HC-27.2)

Concrete masonry units, partly grouted, lightweight (95 lbs/ft3)

1.75 (HC-14.2)

Concrete masonry units, partly grouted, normal weight (135 lbs/ft3)

1.23 (HC-17.5)

Flooring, wood subfloor

0.75

0.94

Gypsum board

0.5

0.45

0.625

0.56

Metal deck

Roofing, built-up

0.375

0.33

Sheathing, vegetable fiber board, 0.78 in.

0.78

2.06

Soil at R-0.104/in.

1.25

Steel, mild

0.0031807

Stucco

0.75

0.08

a. There is no credit for cavities that are open to outside air.

b. Air films do not apply to air cavities within an assembly.

c. For heat capacity for concrete and concrete masonry materials with densities other than the values listed in Table

A101.5, see Tables A3.1B and A3.1C in ASHRAE/IESNA Standard 90.1.

AE-4 2018 Washington State Energy Code

SECTION A102

CEILINGS

A102.1 General. Table A102.1 lists heat loss

coefficients for the opaque portion of exterior

ceilings below vented attics, vaulted ceilings and roof

decks in units of Btu/h × ft

× °F of ceiling.

They are derived from procedures listed in the

ASHRAE Fundamentals Handbook. Ceiling U-

factors are modified for the buffering effect of the

attic, assuming an indoor temperature of 65°F and an

outdoor temperature of 45°F.

A102.1.1 Metal framed ceilings. The nominal R-

values in Table A103.3.6.2: Effective R-Values

for Metal Framing and Cavity Only may be used

for purposes of calculating metal framed ceiling

section U-factors in lieu of the ASHRAE zone

calculation method as provided in Chapter 27 of

the ASHRAE Fundamentals Handbook.

Metal building roofs have a different construction

and are addressed in Table A102.2.5.

A102.2 Component description. The four types of

ceilings are characterized as follows:

A102.2.1 Ceilings below a vented attic. Attic

insulation is assumed to be blown-in, loose-fill

fiberglass with a K-value of 2.6 h × ft

•× °F/Btu

per inch. Full bag count for specified R-value is

assumed in all cases. Ceiling dimensions for flat

ceiling calculations are 45 by 30 feet, with a gabled

roof having a 4/12 pitch. The attic is assumed to

vent naturally at the rate of 3 air changes per hour

through soffit and ridge vents. A void fraction of

0.002 is assumed for all attics with insulation

baffles. Standard-framed, unbaffled attics assume

a void fraction of 0.008.

Attic framing is either standard or advanced.

Standard framing assumes tapering of insulation

depth around the perimeter with resultant decrease

in thermal resistance. An increased R-value is

assumed in the center of the ceiling due to the

effect of piling leftover insulation. Advanced

framing assumes full and even depth of insulation

extending to the outside edge of exterior walls.

Advanced framing does not change from the

default value. U-factors for flat ceilings below

vented attics with standard framing may be

modified with the following table:

Roof Pitch

U-factor for

Standard Framing

R-30

R-38

4/12

0.036

0.031

5/12

0.035

0.030

6/12

0.034

0.029

7/12

0.034

0.029

8/12

0.034

0.028

9/12

0.034

0.028

10/12

0.033

0.028

11/12

0.033

0.027

12/12

0.033

0.027

Vented scissors truss attics assume a ceiling pitch

of 2/12 with a roof pitch of either 4/12 or 5/12.

Unbaffled standard framed scissors truss attics are

assumed to have a void fraction of 0.016.

A102.2.2 Vaulted ceilings. Insulation is assumed

to be fiberglass batts installed in roof joist cavities.

In the vented case, at least 1.5 inches between the

top of the batts and the underside of the roof

sheathing is left open for ventilation in each cavity.

A ventilation rate of 3.0 air changes per hour is

assumed. In the unvented or dense pack case, the

ceiling cavity is assumed to be fully packed with

insulation, leaving no space for ventilation.

A102.2.3 Roof decks. Rigid insulation is applied

to the top of roof decking with no space left for

ventilation. Roofing materials are attached directly

on top of the insulation. Framing members are

often left exposed on the interior side.

A102.2.4 Metal truss framing. Overall system

tested values for the roof/ceiling U

for metal

framed truss assemblies from approved laboratories

shall be used, when such data is acceptable to the

building official.

Alternatively, the U

for roof/ceiling assemblies

using metal truss framing may be obtained from

Tables A102.2.4(1) through A102.2.4(5).

2018 Washington State Energy Code AE-5

TABLE A102.1

DEFAULT U-FACTORS FOR CEILINGS

Standard Frame

Advanced Frame

Ceilings Below Vented Attics

Flat

Baffled

R-19

0.049

0.047

R-30

0.036

0.032

R-38

0.031

0.026

R-49

0.027

0.020

R-60

0.025

0.017

Scissors Truss

R-30 (4/12 roof pitch)

0.043

0.031

R-38 (4/12 roof pitch)

0.040

0.025

R-49 (4/12 roof pitch)

0.038

0.020

R-30 (5/12 roof pitch)

0.039

0.032

R-38 (5/12 roof pitch)

0.035

0.026

R-49 (5/12 roof pitch)

0.032

0.020

Vaulted Ceilings

16" O.C.

24" O.C.

Vented

R-19 2x10 joist

0.049

0.048

R-30 2x12 joist

0.034

0.033

R-38 2x14 joist

0.027

Unvented

R-30 2x10 joist

0.034

0.033

R-38 2x12 joist

0.029

0.027

R-21 + R-21 2x12 joist

0.026

0.025

Roof Deck

4x Beams, 48" O.C.

R-12.5 2" Rigid insulation

0.064

R-21.9 3.5" Rigid insulation

0.040

R-37.5 6" Rigid insulation

0.025

R-50 8" Rigid insulation

0.019

TABLE A102.2.4(1)

STEEL TRUSS

FRAMED CEILING U

Cavity

Truss

Span

(ft)

R-value

0.1075

0.0991

0.0928

0.0878

0.0839

0.0807

0.0780

0.0757

0.0737

0.0720

0.0706

0.0693

0.0681

0.0907

0.0823

0.0760

0.0710

0.0671

0.0638

0.0612

0.0589

0.0569

0.0552

0.0538

0.0525

0.0513

0.0844

0.0759

0.0696

0.0647

0.0607

0.0575

0.0548

0.0525

0.0506

0.0489

0.0474

0.0461

0.0449

0.0789

0.0704

0.0641

0.0592

0.0552

0.0520

0.0493

0.0470

0.0451

0.0434

0.0419

0.0406

0.0395

TABLE A102.2.4(2)

STEEL TRUSS

FRAMED CEILING U

WITH R-3 SHEATHING

Cavity

Truss

Span

(ft)

R-value

0.0809

0.0763

0.0728

0.0701

0.0679

0.0661

0.0647

0.0634

0.0623

0.0614

0.0606

0.0599

0.0592

0.0641

0.0595

0.0560

0.0533

0.0511

0.0493

0.0478

0.0466

0.0455

0.0446

0.0438

0.0431

0.0424

0.0577

0.0531

0.0496

0.0469

0.0447

0.0430

0.0415

0.0402

0.0392

0.0382

0.0374

0.0367

0.0361

0.0523

0.0476

0.0441

0.0414

0.0393

0.0375

0.0360

0.0348

0.0337

0.0328

0.0319

0.0312

0.0306

AE-6 2018 Washington State Energy Code

TABLE A102.2.4(3)

STEEL TRUSS

FRAMED CEILING U

WITH R-5 SHEATHING

Cavity

Truss

Span

(ft)

R-value

0.0732

0.0697

0.0670

0.0649

0.0633

0.0619

0.0608

0.0598

0.0590

0.0583

0.0577

0.0571

0.0567

0.0564

0.0529

0.0502

0.0481

0.0465

0.0451

0.0440

0.0430

0.0422

0.0415

0.0409

0.0403

0.0399

0.0501

0.0465

0.0438

0.0418

0.0401

0.0388

0.0376

0.0367

0.0359

0.0351

0.0345

0.0340

0.0335

0.0446

0.0410

0.0384

0.0363

0.0346

0.0333

0.0322

0.0312

0.0304

0.0297

0.0291

0.0285

0.0280

TABLE A102.2.4(4)

STEEL TRUSS

FRAMED CEILING U

WITH R-10 SHEATHING

Cavity

Truss

Span

(ft)

R-value

0.0626

0.0606

0.0590

0.0578

0.0569

0.0561

0.0555

0.0549

0.0545

0.0541

0.0537

0.0534

0.0531

0.0458

0.0437

0.0422

0.0410

0.0401

0.0393

0.0387

0.0381

0.0377

0.0373

0.0369

0.0366

0.0363

0.0394

0.0374

0.0359

0.0347

0.0337

0.0330

0.0323

0.0318

0.0313

0.0309

0.0305

0.0302

0.0299

0.0339

0.0319

0.0304

0.0292

0.0283

0.0275

0.0268

0.0263

0.0258

0.0254

0.0251

0.0247

0.0245

TABLE A102.2.4(5)

STEEL TRUSS

FRAMED CEILING U

WITH R-15 SHEATHING

Cavity

Truss

Span

(ft)

R-value

0.0561

0.0550

0.0541

0.0535

0.0530

0.0526

0.0522

0.0519

0.0517

0.0515

0.0513

0.0511

0.0509

0.0393

0.0382

0.0373

0.0367

0.0362

0.0358

0.0354

0.0351

0.0349

0.0347

0.0345

0.0343

0.0341

0.0329

0.0318

0.0310

0.0303

0.0298

0.0294

0.0291

0.0288

0.0285

0.0283

0.0281

0.0279

0.0278

0.0274

0.0263

0.0255

0.0249

0.0244

0.0239

0.0236

0.0233

0.0230

0.0228

0.0226

0.0225

0.0223

Footnotes for Tables A102.2.4(1) through A102.2.4(5)

a. Assembly values based on 24 inch on center truss spacing; 11 Truss member connections penetrating insulation (4 at

the eaves, 7 in the interior space); ½ inch drywall ceiling; all truss members are 2x4 "C" channels with a solid web.

b. Ceiling sheathing installed between bottom chord and drywall.

A102.2.5 Metal building roof. Table A102.2.5:

The base assembly is a roof where the insulation is

compressed when installed beneath metal roof

panels attached to the steel structure (purlins).

Additional assemblies include continuous

insulation, uncompressed and uninterrupted by

framing.

U-factors for metal building roofs shall be taken

from Table A102.2.5, provided the average purlin

spacing is at least 52 inches and the R-value of the

thermal spacer block is greater than or equal to the

thermal spacer block R-value indicated in Table

A107.2.5 for the assembly. It is not acceptable to

use the U-factors in Tables A102.2.6(1),

A102.2.6(2) or A102.2.6(3) if additional insulated

sheathing is not continuous.

A102.2.5.1 Single layer. The rated R-value of

insulation is for insulation installed

perpendicular to and draped over purlins and

then compressed when the metal roof panels are

attached. A minimum R-3 (R-0.5) thermal

spacer block between the purlins and the metal

roof panels is required, unless compliance is

shown by the overall assembly U-factor.

A102.2.5.2 Double layer. The first rated R-

value of insulation is for insulation installed

perpendicular to and draped over purlins. The

second rated R-value of insulation is for unfaced

insulation installed above the first layer and

parallel to the purlins and then compressed when

the metal roof panels are attached. A minimum

R-3 (R-0.5) thermal spacer block between the

purlins and the metal roof panels is required,

unless compliance is shown by the overall

assembly U-factor.

A102.2.5.3 Continuous insulation. For

2018 Washington State Energy Code AE-7

continuous insulation (e.g., insulation boards or

blankets), it is assumed that the insulation is

installed below the purlins and is uninterrupted

by framing members. Insulation exposed to the

conditioned space or semi-heated space shall

have a facing, and all insulation seams shall be

continuously sealed to provide a continuous air

barrier.

A102.2.5.4 Liner system (Ls). A continuous

membrane is installed below the purlins and

uninterrupted by framing members.

Uncompressed, unfaced insulation rests on top of

the membrane between the purlins. For

multilayer installations, the last rated R-value of

insulation is for unfaced insulation draped over

purlins and then compressed when the metal roof

panels are attached. A minimum R-3 (R-0.5)

thermal spacer block between the purlins and the

metal roof panels is required, unless compliance

is shown by the overall assembly U-factor.

A102.2.5.5 Filled cavity. The first rated R-

value of insulation is for faced insulation

installed parallel to the purlins. The second rated

R-value of insulation is for unfaced insulation

installed above the first layer, parallel to and

between the purlins and compressed when the

metal roof panels are attached. The facer of the

first layer of insulation is of sufficient width to

be continuously sealed to the top flange of the

purlins and to accommodate the full thickness of

the second layer of insulation. A supporting

structure retains the bottom of the first layer at

the prescribed depth required for the full

thickness of the second layer of insulation being

installed above it. A minimum R-5 (R-0.9)

thermal spacer block between the purlins and the

metal roof panels is required, unless compliance

is shown by the overall assembly U-factor.

A102.2.6 Roofs with insulation entirely above

deck (uninterrupted by framing). Table

A102.2.6(1) through A102.2.6(3): The base

assembly is continuous insulation over a

structural deck. These tables indicate effective

U-factors for tapered roof insulation, sloped from

a maximum R-value (R

max

) at the peak of the

slope to a minimum R-value (R

min

) at the low

point of the slope. The rows of the tables

represent the rated R-value of the insulation at

the minimum conditions (except at roof drains)

and the columns of the table represent the rated

R-value of the insulation at the maximum

conditions. The slope of the tapered insulation

shall be no greater than 1/4 inch per foot.

AE-8 2018 Washington State Energy Code

TABLE A102.2.5

DEFAULT U-FACTORS FOR METAL BUILDING ROOFS

Insulation

System

Rated R-Value

of Insulation

Overall U-Factor

for Entire Base

Roof Assembly

Overall U-Factor for Assembly of Base Roof Plus

Continuous Insulation (uninterrupted by framing)

Rated R-Value of Continuous Insulation

R-6.5

R-13

R-19.5

R-26

R-32.5

R-39

Standing Seam Roofs with Thermal Spacer Blocks

a,b

Single

Layer

None

1.280

0.137

0.073

0.049

0.037

0.030

0.025

R-10

0.115

0.066

0.046

0.035

0.029

0.024

0.021

R-11

0.107

0.063

0.045

0.035

0.028

0.024

0.021

R-13

0.101

0.061

0.044

0.034

0.028

0.024

0.020

R-16

0.096

0.059

0.043

0.033

0.027

0.023

0.020

R-19

0.082

0.053

0.040

0.031

0.026

0.022

0.020

Double

Layer

R-10 .+ R-10

0.088

0.056

0.041

0.032

0.027

0.023

0.020

R-10 .+ R-11

0.086

0.055

0.041

0.032

0.027

0.023

0.020

R-11 .+ R-11

0.085

0.055

0.040

0.032

0.026

0.023

0.020

R-10 .+ R-13

0.084

0.054

0.040

0.032

0.026

0.023

0.020

R-11 .+ R-13

0.082

0.053

0.040

0.032

0.026

0.022

0.020

R-13 .+ R-13

0.075

0.050

0.038

0.030

0.025

0.022

0.019

R10 .+ R-19

0.074

0.050

0.038

0.030

0.025

0.022

0.019

R-11 .+ R-19

0.072

0.049

0.037

0.030

0.025

0.022

0.019

R-13 .+ R-19

0.068

0.047

0.036

0.029

0.025

0.021

0.019

R-16 .+ R-19

0.065

0.046

0.035

0.029

0.024

0.021

0.018

R-19 .+ R-19

0.060

0.043

0.034

0.028

0.023

0.020

0.018

Liner

System

R-19 .+ R-11

0.035

R-25 .+ R-11

0.031

R-30 .+ R-11

0.029

R-25 .+

R-11 .+ R-11

0.026

Filled Cavity with Thermal Spacer Blocks

R-10 .+ R-19

0.057

0.042

0.033

0.027

0.023

0.020

0.018

Standing Seam Roofs without Thermal Spacer Blocks

Liner

System

R-19 .+ R-11

0.040

Thru-Fastened Roofs without Thermal Spacer Blocks

Single

Layer

R-10

0.184

R-11

0.182

R-13

0.174

R-16

0.157

R-19

0.151

Liner

System

R-19 .+ R-11

0.044

(Multiple R-values are listed in order from inside to outside)

a. A standing seam roof clip that provides a minimum 1.5 in. distance between the top of the purlins and the underside of the

metal roof panels is required.

b. A minimum R-3 thermal spacer block is required.

c. A minimum R-5 thermal spacer block is required.

2018 Washington State Energy Code AE-9

TABLE A102.2.6(1)

ASSEMBLY U-FACTORS FOR ROOFS WITH TAPERED INSULATION ENTIRELY ABOVE DECK

SINGLE SLOPE RECTANGULAR TO ONE-SIDE

,d,f,g,h,i

(UNINTERRUPTED BY FRAMING)

TABLE A102.2.6(2)

ASSEMBLY U-FACTORS FOR ROOFS WITH TAPERED INSULATION ENTIRELY ABOVE DECK

SLOPED TRIANGLE (ROOF WITH CENTER DRAIN)

e,f,g,h,i

(UNINTERRUPTED BY FRAMING)

AE-10 2018 Washington State Energy Code

TABLE A102.2.6(3)

ASSEMBLY U-FACTORS FOR ROOFS WITH TAPERED INSULATION ENTIRELY ABOVE DECK

SLOPED TRIANGLE (ROOF WITH PERIMETER DRAINS)

e,f,g,h,i

(UNINTERRUPTED BY FRAMING)

Footnotes to Tables A102.2.6.1, A102.2.6.2, and A102.2.6.3:

a. R

max

and R

min

are determined along the linearly tapered cross section for the respective minimum and maximum

thickness values for the roof section being analyzed. For triangular roof sections

b. R

max

refers to the insulation value along the long edge of the triangle and R

min

to the insulation at the point of the

triangle which assumes that the insulation slopes to the center.

c. R

max

refers to the insulation value at the point of the triangle and R

min

to the insulation along the long edge of the

triangle which assumes that the insulation slopes to the perimeter.

d. Effective U-factor for rectangular tapered insulation is calculated as follows:

















min

max

minmax

eff

e. Effective U-factor for triangular tapered insulation is calculated as follows:

max

min

minmax

min

minmax

ln1















































eff

f. Assembly U-factors include an exterior air film (R=0.17) and an interior air film, horizontal with heat flow up

(R=0.61).

g. For effective U-factors of roof assemblies with different R

max

or R

min

values not listed in the tables interpolation is

allowed.

h. This table shall only be applied to tapered insulation that is tapered along only one axis.

i. In areas of differing insulation slopes/configurations, individual U-values shall be calculated and an area weighted U-

value calculation shall be used to determine the effective value of the roof.

2018 Washington State Energy Code AE-11

SECTION A103

ABOVE GRADE WALLS

A103.1 General. The tables in this section list heat

loss coefficients for the opaque portion of above-

grade wood stud frame walls, metal stud frame walls

and concrete masonry walls (Btu/h × ft

× °F). They

are derived from procedures listed in the ASHRAE

Fundamentals Handbook. For intermediate floor

slabs which penetrate the insulated wall, use the

concrete wall U-factors in Table A103.3.7.1(1).

Insulation is assumed to uniformly fill the entire

cavity and to be installed as per manufacturer's

directions. All walls are assumed to be finished on

the inside with 1/2 inch gypsum wallboard, and on

the outside with either beveled wood siding over 1/2

inch plywood sheathing or with 5/8 inch T1-11

siding. Insulated sheathing (either interior or

exterior) is assumed to cover the entire opaque wall

surface, except where modified in accordance with

footnote g to Table C402.1.3.

Metal building walls have a different construction

and are addressed in Table A103.3.6.3.

A103.2 Framing description. For wood stud frame

walls, three framing types are considered and defined

as follows:

A103.2.1 Standard. Studs framed on 16 inch

centers with double top plate and single bottom

plate. Corners use three studs and each opening is

framed using two studs. Headers consist of double

2x or single 4x material with an air space left

between the header and the exterior sheathing.

Interior partition wall/exterior wall intersections

use two studs in the exterior wall.

Standard framing weighting factors:

Studs and plates 0.19

Insulated cavity 0.77

Headers 0.04

A103.2.2 Intermediate. Studs framed on 16 inch

centers with double top plate and single bottom

plate. Corners use two studs or other means of

fully insulating corners, and each opening is

framed by two studs. Headers consist of double 2x

material with R-10 insulation. Interior partition

wall/exterior wall intersections are fully insulated

in the exterior wall.

Intermediate framing weighting factors:

Studs and plates 0.18

Insulated cavity 0.78

Headers 0.04

A103.2.3 Advanced. Studs framed on 24 inch

centers with double top plate and single bottom

plate. Corners use two studs or other means of

fully insulating corners, and one stud is used to

support each header. Headers consist of double 2x

material with R-10 insulation. Interior partition

wall/exterior wall intersections are fully insulated

in the exterior wall.

Advanced framing weighting factors:

Studs and plates 0.13

Insulated cavity 0.83

Headers 0.04

A103.3 Component description. Default

coefficients for the following types of walls are

listed: Single-stud walls, strap walls, double-stud

walls, log walls, stress-skin panels, metal stud walls,

and metal building walls.

A103.3.1 Single-stud wall. Tables A103.3.1(1)

through A103.3.1(8): Assumes either 2 x 4 or 2 x 6

studs framed on 16 or 24 inch centers. Headers are

solid for 2 x 4 walls and double 2x for 2 x 6 walls,

with either dead-air or rigid-board insulation in the

remaining space.

AE-12 2018 Washington State Energy Code

TABLE A103.3.1(1)

2 x 4 Single Wood Stud: R-11 Batt

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

ADV

STD

ADV

Nominal Batt R-value:

0.088

0.084

0.094

0.090

R-11 at 3.5 inch thickness

0.080

0.077

0.085

0.082

0.074

0.071

0.078

0.075

Installed Batt R-value:

0.069

0.066

0.072

0.070

R-11 in 3.5 inch cavity

0.064

0.062

0.067

0.065

0.060

0.058

0.063

0.061

0.056

0.055

0.059

0.057

0.053

0.052

0.055

0.054

0.051

0.049

0.052

0.051

0.048

0.047

0.050

0.049

0.046

0.045

0.047

0.046

0.044

0.043

0.045

0.044

0.042

0.041

0.043

0.042

TABLE A103.3.1(2)

2 x 4 Single Wood Stud: R-13 Batt

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

ADV

STD

ADV

Nominal Batt R-value:

0.082

0.078

0.088

0.083

R-13 at 3.63 inch thickness

0.075

0.072

0.080

0.076

0.069

0.066

0.073

0.070

Installed Batt R-value:

0.065

0.062

0.068

0.065

R-12.7 in 3.5 inch cavity

0.060

0.058

0.063

0.061

0.057

0.055

0.059

0.057

0.053

0.052

0.056

0.054

0.051

0.049

0.052

0.051

0.048

0.047

0.050

0.048

0.046

0.045

0.047

0.046

0.044

0.043

0.045

0.044

0.042

0.041

0.043

0.042

0.040

0.039

0.041

0.040

2018 Washington State Energy Code AE-13

TABLE A103.3.1(3)

2 x 4 Single Wood Stud: R-15 Batt

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

ADV

STD

ADV

Nominal Batt R-value:

0.076

0.071

0.081

0.075

R-15 at 3.5 inch thickness

0.069

0.065

0.073

0.069

0.064

0.061

0.068

0.069

Installed Batt R-value:

0.060

0.057

0.063

0.059

R-15 in 3.5 inch cavity

0.056

0.053

0.059

0.056

0.053

0.051

0.055

0.052

0.050

0.048

0.052

0.050

0.047

0.046

0.049

0.047

0.045

0.044

0.047

0.045

0.043

0.042

0.044

0.043

0.041

0.040

0.042

0.041

0.039

0.038

0.041

0.039

0.038

0.037

0.039

0.038

TABLE A103.3.1(4)

2 x 6 Single Wood Stud: R-19 Batt

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

INT

ADV

STD

INT

ADV

Nominal Batt R-value:

0.062

0.058

0.055

0.065

0.061

0.058

R-19 at 6 inch thickness

0.058

0.055

0.052

0.060

0.057

0.055

0.054

0.052

0.050

0.056

0.054

0.051

Installed Batt R-value:

0.051

0.049

0.047

0.053

0.051

0.049

R-18 in 5.5 inch cavity

0.048

0.046

0.045

0.050

0.048

0.046

0.044

0.043

0.048

0.046

0.044

0.042

0.041

0.045

0.044

0.042

0.040

0.039

0.043

0.042

0.040

0.039

0.038

0.041

0.040

0.039

0.038

0.037

0.035

0.039

0.038

0.037

0.036

0.035

0.038

0.037

0.036

0.035

0.034

0.036

0.035

0.034

0.033

0.035

0.034

0.033

AE-14 2018 Washington State Energy Code

TABLE A103.3.1(5)

2 x 6 Single Wood Stud: R-21 Batt

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

INT

ADV

STD

INT

ADV

Nominal Batt R-value:

0.057

0.054

0.051

0.060

0.056

0.053

R-21 at 5.5 inch thickness

0.054

0.051

0.048

0.056

0.053

0.050

0.048

0.045

0.052

0.050

0.047

Installed Batt R-value:

0.048

0.045

0.043

0.049

0.047

0.045

R-21 in 5.5 inch cavity

0.045

0.043

0.041

0.047

0.045

0.043

0.041

0.040

0.044

0.042

0.041

0.039

0.038

0.042

0.041

0.039

0.038

0.036

0.040

0.039

0.037

0.038

0.036

0.035

0.039

0.037

0.036

0.035

0.034

0.037

0.036

0.035

0.034

0.033

0.036

0.035

0.033

0.032

0.034

0.033

0.032

0.031

0.033

0.032

0.031

TABLE A103.3.1(6)

2 x 6 Single Wood Stud: R-22 Batt

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

INT

ADV

STD

INT

ADV

Nominal Batt R-value:

0.059

0.055

0.052

0.062

0.058

0.054

R-22 at 6.75 inch thickness

0.055

0.052

0.049

0.057

0.054

0.051

0.052

0.049

0.047

0.054

0.051

0.048

Installed Batt R-value:

0.049

0.046

0.044

0.050

0.048

0.046

R-20 in 5.5 inch cavity

0.046

0.044

0.042

0.048

0.046

0.044

0.042

0.041

0.045

0.043

0.042

0.040

0.039

0.043

0.042

0.040

0.039

0.037

0.041

0.040

0.038

0.037

0.036

0.039

0.038

0.037

0.036

0.035

0.038

0.037

0.035

0.034

0.033

0.036

0.035

0.034

0.033

0.032

0.035

0.034

0.033

0.032

0.031

0.034

0.033

0.032

2018 Washington State Energy Code AE-15

TABLE A103.3.1(7)

2 x 6 Single Wood Stud: Two R-11 Batts

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

INT

ADV

STD

INT

ADV

Nominal Batt R-value:

0.060

0.057

0.054

0.063

0.059

0.056

R-22 at 7 inch thickness

0.056

0.053

0.051

0.059

0.056

0.053

0.050

0.048

0.055

0.052

0.050

Installed Batt R-value:

0.050

0.048

0.046

0.052

0.049

0.047

R-18.9 in 5.5 inch cavity

0.047

0.045

0.044

0.049

0.047

0.045

0.043

0.042

0.046

0.045

0.043

0.041

0.040

0.044

0.043

0.041

0.040

0.038

0.042

0.041

0.039

0.038

0.037

0.040

0.039

0.038

0.037

0.036

0.039

0.038

0.036

0.035

0.034

0.037

0.036

0.035

0.034

0.033

0.036

0.035

0.034

0.033

0.032

0.034

0.033

TABLE A103.3.1(8)

2 x 8 Single Stud: R-25 Batt

Siding Material/Framing Type

R-value of

Foam Board

Lapped Wood

T1-11

NOTE:

STD

INT

ADV

STD

INT

ADV

Nominal Batt R-value:

0.051

0.047

0.045

0.053

0.049

0.046

R-25 at 8 inch thickness

0.048

0.045

0.043

0.049

0.046

0.044

0.045

0.043

0.041

0.047

0.044

0.042

Installed Batt R-value:

0.043

0.041

0.039

0.044

0.042

0.040

R-23.6 in 7.25 inch cavity

0.041

0.039

0.037

0.042

0.040

0.038

0.039

0.037

0.036

0.040

0.038

0.037

0.036

0.035

0.038

0.037

0.036

0.035

0.033

0.037

0.035

0.034

0.035

0.033

0.032

0.035

0.034

0.033

0.032

0.031

0.034

0.033

0.032

0.031

0.030

0.033

0.032

0.031

0.030

0.029

0.032

0.031

0.030

0.029

0.028

0.031

0.030

0.029

AE-16 2018 Washington State Energy Code

A103.3.2 Strap wall. Table A103.3.2: Assumes

2 x 6 studs framed on 16 or 24 inch centers. 2 x 3

or 2 x 4 strapping is run horizontally along the

interior surface of the wall to provide additional

space for insulation.

A103.3.3 Double stud wall. Tables A103.3.3(1)

and A103.3.3(2): Assumes an exterior structural

wall and a separate interior, nonstructural wall.

Insulation is placed in both wall cavities and in the

space between the two walls. Stud spacing is

assumed to be on 24 inch centers for both walls.

A103.3.4 Log wall. U-factors for log walls shall

be determined using ICC 400 Table 305.3.1.1, U-

Factor of Log Wall (U

) by Log Thickness (W

)

and Specific Gravity.

A103.3.5 Stress-skin panel. See Table A103.3.5.

TABLE A103.3.2

2 X 6: STRAP WALL

Siding Material/Frame Type

Lapped Wood

T1-11

STD

ADV

STD

ADV

R-19 + R-11 Batts

0.036

0.035

0.038

0.036

R-19 + R-8 Batts

0.041

0.039

0.042

0.040

TABLE A103.3.3(1)

2 X 6 + 2 X 4: DOUBLE WOOD STUD

Siding Material/Frame Type

Batt Configuration

Lapped Wood

T1-11

Exterior

Middle

Interior

STD

ADV

STD

ADV

R-19

R-11

0.040

0.037

0.041

0.038

R-19

0.034

0.031

0.035

0.032

R-19

R-8

R-11

0.029

0.028

0.031

0.029

R-19

R-11

0.027

0.026

0.028

0.027

R-19

R-11

R-19

0.024

0.023

0.025

0.023

R-19

0.021

0.020

0.021

0.020

TABLE A103.3.3(2)

2 X 4 + 2 X 4: DOUBLE WOOD STUD

Siding Material/Frame Type

Batt Configuration

Lapped Wood

T1-11

Exterior

Middle

Interior

STD

ADV

STD

ADV

R-11

0.050

0.046

0.052

0.048

R-19

R-11

0.039

0.037

0.043

0.039

R-11

R-8

R-11

0.037

0.035

0.036

R-11

0.032

0.031

0.033

0.032

R-13

0.029

0.028

0.029

0.028

R-11

R-19

R-11

0.026

0.027

0.026

2018 Washington State Energy Code AE-17

TABLE A103.3.5

STRESS SKIN PANEL

NOTE:

R-value of expanded

polystyrene: R-3.85

per inch

Framing: 6%

Spline: 8%

Panel

Thickness,

Inches

U-factor

3 1/2

0.071

5 1/2

0.048

7 1/4

0.037

9 1/4

0.030

11 1/4

0.025

No thermal bridging between interior and exterior splines

A103.3.6 Metal stud walls. The nominal R-values

in Tables A103.3.6.1 through A103.3.6.3 may be

used for purposes of calculating metal stud wall

section U-factors in lieu of the ASHRAE zone

calculation method as provided in Chapter 27 of

the ASHRAE Fundamentals Handbook.

A103.3.6.1 Metal stud wall, overall assembly

U-factors. Tables A103.3.6.1(1) and

A103.6.1(2): Assumes metal studs spaced on 16

or 24 inch centers with insulation installed to fill

wall cavities. Continuous rigid board insulation

is applied without creating uninsulated voids in

the wall assembly.

A103.3.6.2 Metal stud wall, effective R-values

for metal framing and cavity only. Table

A103.3.6.2: These values may be used for the

metal-framing/cavity layers in walls with metal

studs spaced on 16- or 24-inch centers with

insulation installed to fill wall cavities in lieu of

using the zone method provided in Chapter 25 of

the ASHRAE Fundamentals Handbook.

A103.3.6.3 Metal building wall. Table

A103.3.6.3: A wall whose structure consists of

metal spanning panels supported by steel

structural members (does not include spandrel

glass or metal panels in curtain wall systems).

The first nominal R-value is for insulation

compressed between metal wall panels and the

steel structure. For double-layer installations,

the second rated R-value of insulation is for

insulation installed from the inside, covering the

girts. For continuous insulation (e.g., insulation

boards) it is assumed that the insulation boards

are installed on the inside of the girts and

uninterrupted by the framing members.

Insulation exposed to the conditioned space or

semi-heated space shall have a facing, and all

insulation seams shall be continuously sealed to

provide a continuous air barrier.

A103.3.7 Concrete and masonry walls.

A103.3.7.1 Concrete masonry walls. The

nominal R-values in Tables A103.3.7.1(1) and

A103.3.7.1(2) may be used for purposes of

calculating concrete masonry wall section U-

factors in lieu of the ASHRAE isothermal planes

calculation method as provided in Chapter 27 of

the ASHRAE Fundamentals Handbook

A103.3.7.2 Peripheral edges of intermediate

concrete floors. See Table A103.3.7.2.

AE-18 2018 Washington State Energy Code

TABLE A103.3.6.1(1)

OVERALL ASSEMBLY U-FACTORS

FOR METAL STUD WALLS WITH CONTINUOUS INSULATION

R-Value of

Cavity Insulation

Metal

Framing

Continuous

Foam Board

Insulation

R-0

R-11

R-13

R-15

R-19

R-21

16” o.c.

R-0 (none)

0.352

0.132

0.124

0.118

0.109

0.106

R-1

0.260

0.117

0.111

0.106

0.099

0.096

R-2

0.207

0.105

0.100

0.096

0.090

0.087

R-3

0.171

0.095

0.091

0.087

0.082

0.080

R-4

0.146

0.087

0.083

0.080

0.076

0.074

R-5

0.128

0.080

0.077

0.074

0.071

0.069

R-6

0.113

0.074

0.071

0.069

0.066

0.065

R-7

0.102

0.069

0.066

0.065

0.062

0.061

R-8

0.092

0.064

0.062

0.061

0.058

0.057

R-9

0.084

0.060

0.059

0.057

0.055

0.054

R-10

0.078

0.057

0.055

0.054

0.052

0.051

R-11

0.072

0.054

0.052

0.051

0.050

0.049

R-12

0.067

0.051

0.050

0.049

0.047

R-13

0.063

0.049

0.048

0.047

0.045

R-14

0.059

0.046

0.045

0.043

R-15

0.056

0.044

0.043

0.041

R-20

0.044

0.036

0.035

0.034

24” o.c

R-0 (none)

0.338

0.116

0.108

0.102

0.094

0.090

R-1

0.253

0.104

0.098

0.092

0.086

0.083

R-2

0.202

0.094

0.089

0.084

0.079

0.077

R-3

0.168

0.086

0.082

0.078

0.073

0.071

R-4

0.144

0.079

0.075

0.072

0.068

0.066

R-5

0.126

0.073

0.070

0.067

0.064

0.062

R-6

0.112

0.068

0.066

0.063

0.060

0.059

R-7

0.100

0.064

0.062

0.059

0.057

0.055

R-8

0.091

0.060

0.058

0.056

0.054

0.052

R-9

0.084

0.057

0.055

0.053

0.051

0.050

R-10

0.077

0.054

0.052

0.050

0.048

R-11

0.072

0.051

0.049

0.048

0.046

0.045

R-12

0.067

0.048

0.047

0.046

0.044

0.043

R-13

0.063

0.046

0.045

0.044

0.042

R-14

0.059

0.044

0.043

0.042

0.041

0.040

R-15

0.056

0.042

0.041

0.040

0.039

0.038

R-20

0.044

0.035

0.034

0.033

0.032

Continuous foam board insulation: Continuous insulation assumes no thermal bridging of insulation by framing or z-furring

through applied foam board. Zone calculation method as provided in the ASHRAE Fundamentals Handbook must be used for

thermally bridged foam board insulation. Values for attachment of insulation with z-furring are given in Table A103.3.6.1(2).

2018 Washington State Energy Code AE-19

TABLE A105.3.6.1(2)

OVERALL ASSEMBLY U-FACTORS FOR METAL STUD WALLS

WITH INSULATION SUPPORTED BY Z-FURRING

Metal

Framing

R-value of

Foam Board

Insulation

Z-furring

Attachment

Cavity Insulation

R-0

R-11

R-13

R-15

R-19

R-21

16” o.c.

R-0 (none)

Horizontal

0.352

0.132

0.124

0.118

0.109

0.106

R-5

Horizontal

0.155

0.089

0.086

0.083

0.078

0.077

R-7.5

Horizontal

0.128

0.080

0.077

0.074

0.071

0.069

R-10

Horizontal

0.110

0.072

0.070

0.068

0.065

0.064

R-12.5

Horizontal

0.099

0.068

0.065

0.064

0.061

0.060

R-15

Horizontal

0.091

0.064

0.062

0.060

0.058

0.057

R-17.5

Horizontal

0.084

0.060

0.058

0.057

0.055

0.054

R-20

Horizontal

0.078

0.057

0.056

0.054

0.052

R-22.5

Horizontal

0.074

0.055

0.054

0.052

0.051

0.050

R-25

Horizontal

0.071

0.053

0.052

0.051

0.049

0.048

R-0 (none)

Vertical

0.352

0.132

0.124

0.118

0.109

0.106

R-5

Vertical

0.165

0.093

0.089

0.086

0.081

0.079

R-7.5

Vertical

0.142

0.085

0.081

0.079

0.075

0.073

R-10

Vertical

0.126

0.079

0.076

0.074

0.070

0.069

R-12.5

Vertical

0.115

0.074

0.072

0.070

0.066

0.065

R-15

Vertical

0.107

0.071

0.069

0.067

0.064

0.063

R-17.5

Vertical

0.100

0.068

0.065

0.064

0.061

0.060

R-20

Vertical

0.094

0.065

0.063

0.061

0.059

0.058

R-22.5

Vertical

0.090

0.063

0.061

0.060

0.057

0.056

R-25

Vertical

0.086

0.061

0.059

0.058

0.056

0.055

24” o.c.

R-0 (none)

Horizontal

0.338

0.116

0.108

0.102

0.094

0.09

R-5

Horizontal

0.152

0.082

0.078

0.074

0.070

0.068

R-7.5

Horizontal

0.126

0.074

0.070

0.068

0.064

0.062

R-10

Horizontal

0.109

0.067

0.065

0.062

0.059

0.058

R-12.5

Horizontal

0.098

0.063

0.061

0.059

0.056

0.055

R-15

Horizontal

0.090

0.060

0.058

0.056

0.053

0.052

R-17.5

Horizontal

0.083

0.057

0.055

0.053

0.051

0.050

R-20

Horizontal

0.078

0.054

0.052

0.051

0.049

0.048

R-22.5

Horizontal

0.074

0.052

0.050

0.049

0.047

0.046

R-25

Horizontal

0.070

0.050

0.049

0.047

0.046

0.045

R-0 (none)

Vertical

0.338

0.116

0.108

0.102

0.094

0.09

R-5

Vertical

0.162

0.084

0.080

0.077

0.072

0.070

R-7.5

Vertical

0.140

0.078

0.074

0.071

0.067

0.065

R-10

Vertical

0.124

0.073

0.070

0.067

0.063

0.062

R-12.5

Vertical

0.113

0.069

0.066

0.064

0.061

0.059

R-15

Vertical

0.106

0.066

0.063

0.061

0.058

0.057

R-17.5

Vertical

0.098

0.063

0.061

0.059

0.056

0.055

R-20

Vertical

0.093

0.061

0.059

0.057

0.054

0.053

R-22.5

Vertical

0.089

0.059

0.057

0.055

0.053

0.051

R-25

Vertical

0.085

0.057

0.055

0.054

0.051

0.050

Values may in Table A105.3.6.1(2) may not interpolated between. The value of the foam board insulation must meet exceed the

value listed in the table in order to use the value shown.

AE-20 2018 Washington State Energy Code

TABLE A103.3.6.2

EFFECTIVE R-VALUES FOR METAL FRAMING AND CAVITY ONLY

Cavity

Insulation

Nominal

Depth, Inches

Actual Depth,

Inches

Nominal

R-Value

Effective R-Value

16” O.C.

24” O.C.

Air Cavity

Any

R-0.91 (air)

0.79

0.91

Wall

3-1/2

R-11

5.5

6.6

3-1/2

R-13

6.0

7.2

3-1/2

R-15

6.4

7.8

5-1/2

R-19

7.1

8.6

5-1/2

R-21

7.4

9.0

7-1/4

R-25

7.8

9.6

Roof

Insulation is

uncompressed

R-11

5.5

6.1

R-19

7.0

9.1

R-30

9.3

11.4

TABLE A103.3.6.3

DEFAULT METAL BUILDING WALL U-FACTORS

Insulation

System

Rated R-

Value of

Insulation

Overall

U-fFactor for

Entire

Base Wall

Assembly

Overall U-Factor for Assembly of Base Wall Plus Continuous

Insulation (Uninterrupted by Framing)

R-6.5

R-13

R-19.5

R-26

R-32.5

R-39

Single Layer of Mineral Fiber

None

1.180

0.136

0.072

0.049

0.037

0.030

0.025

R-10

0.186

0.084

0.054

0.040

0.032

0.026

0.023

R-11

0.185

0.084

0.054

0.040

0.032

0.026

0.023

R-13

0.162

0.079

0.052

0.039

0.031

0.026

0.022

R-16

0.155

0.077

0.051

0.039

0.031

0.026

0.022

R-19

0.147

0.075

0.050

0.038

0.030

0.025

0.022

2018 Washington State Energy Code AE-21

TABLE A103.3.7.1(1)

DEFAULT U-FACTORS FOR CONCRETE AND MASONRY WALLS

8" Concrete Masonry

WALL DESCRIPTION

CORE TREATMENT

Partial Grout with Ungrouted Cores

Solid Grout

Empty

Loose-fill insulated

Perlite

Vermiculite

Exposed Block, Both Sides

0.40

0.23

0.24

0.43

R-5 Interior Insulation, Wood Furring

0.14

0.11

0.12

0.15

R-6 Interior Insulation, Wood Furring

0.14

0.11

0.14

R-10.5 Interior Insulation, Wood Furring

0.11

0.09

0.11

R-8 Interior Insulation, Metal Clips

0.11

0.09

0.11

R-6 Exterior Insulation

0.12

0.10

0.12

R-10 Exterior Insulation

0.08

0.07

0.08

R-9.5 Rigid Polystyrene Integral Insulation, Two

Webbed Block

0.11

0.09

0.12

12" Concrete Masonry

WALL DESCRIPTION

CORE TREATMENT

Partial Grout with Ungrouted Cores

Solid Grout

Empty

Loose-fill insulated

Perlite

Vermiculite

Exposed Block, Both Sides

0.35

0.17

0.18

0.33

R-5 Interior Insulation, Wood Furring

0.14

0.10

0.13

R-6 Interior Insulation, Wood Furring

0.13

0.09

0.10

0.13

R-10.5 Interior Insulation, Wood Furring

0.11

0.08

0.10

R-8 Interior Insulation, Metal Clips

0.10

0.08

0.09

R-6 Exterior Insulation

0.11

0.09

0.11

R-10 Exterior Insulation

0.08

0.06

0.08

R-9.5 Rigid Polystyrene Integral Insulation,

Two Webbed Block

0.11

0.08

0.09

0.12

8" Clay Brick

WALL DESCRIPTION

CORE TREATMENT

Partial Grout with Ungrouted Cores

Solid Grout

Empty

Loose-fill insulated

Perlite

Vermiculite

Exposed Block, Both Sides

0.50

0.31

0.32

0.56

R-5 Interior Insulation, Wood Furring

0.15

0.13

0.16

R-6 Interior Insulation, Wood Furring

0.15

0.12

0.15

R-10.5 Interior Insulation, Wood Furring

0.12

0.10

0.12

R-8 Interior Insulation, Metal Clips

0.11

0.10

0.11

R-6 Exterior Insulation

0.12

0.11

0.13

R-10 Exterior Insulation

0.08

0.09

AE-22 2018 Washington State Energy Code

TABLE A103.3.7.1(1) – continued

DEFAULT U-FACTORS FOR CONCRETE AND MASONRY WALLS

6" Concrete Poured or Precast

WALL DESCRIPTION

CORE TREATMENT

Partial Grout with Ungrouted Cores

Solid Grout

Empty

Loose-fill insulated

Perlite

Vermiculite

Exposed Concrete, Both Sides

0.61

R-5 Interior Insulation, Wood Furring

0.16

R-6 Interior Insulation, Wood Furring

0.15

R-10.5 Interior Insulation, Wood Furring

0.12

R-8 Interior Insulation, Metal Clips

0.12

R-6 Exterior Insulation

0.13

R-10 Exterior Insulation

0.09

1. Grouted cores at 40" x 48" on center vertically and horizontally in partial grouted walls.

2. Interior insulation values include 1/2" gypsum board on the inner surface.

3. Furring and stud spacing is 16" on center. Insulation is assumed to fill furring space and is not compressed.

4. Intermediate values may be interpolated using this table. Values not contained in this table may be computed using the

procedures listed in the ASHRAE Fundamentals Handbook.

5. Concrete Masonry Unit (CMU) assembly U-values are based on local test data for Washington state CMU block material

using the ASTM C-236-87 steady state thermal conductance test. Tests included an 8"x8"x16" CMU with all cells filled

with vermiculite (1995) and 8"x8"x16" CMU with all cells filled with polymaster foam in place insulation (1996).

Refer to ASHRAE Standard 90.1 for additional nationally recognized data on the thermal performance of

CMU block walls.

TABLE A103.3.7.1(2)

DEFAULT U-FACTORS FOR CONCRETE AND MASONRY WALLS

a,b,c,d

Framing Type

and Depth

Rated R-Value of

Insulation Alone

Assembly U-Factors

for Solid Concrete

Walls

Assembly U-Factors

for Concrete Block

Walls:

Solid Grouted

Assembly U-Factors for

Concrete Block Walls:

Partially Grouted

(cores uninsulated

except where specified)

Base Wall only

No Framing

R-0

U-0.740

U-0.580

U-0.480

Ungrouted Cores Filled

with Loose-Fill

Insulation

N.A.

U-0.350

Continuous Wood Framing

0.75 in.

R-3.0

U-0.247

U-0.226

U-0.210

1.5 in.

R-6.0

U-0.160

U-0.151

U-0.143

2.0 in.

R-10.0

U-0.116

U-0.111

U-0.107

3.5 in.

R-11.0

U-0.094

U-0.091

U-0.088

3.5 in.

R-13.0

U-0.085

U-0.083

U-0.080

3.5 in.

R-15.0

U-0.079

U-0.077

U-0.075

5.5 in.

R-19.0

U-0.060

U-0.059

U-0.058

5.5 in.

R-21.0

U-0.057

U-0.055

U-0.054

2018 Washington State Energy Code AE-23

TABLE A103.3.7.1(2) (Continued)

DEFAULT U-FACTORS FOR CONCRETE AND MASONRY WALLS

Framing Type

and Depth

Rated R-Value of

Insulation Alone

Assembly U-Factors

for Solid Concrete

Walls

Assembly U-Factors

for Concrete Block

Walls:

Solid Grouted

Assembly U-Factors for

Concrete Block Walls:

Partially Grouted

(cores uninsulated

except where specified)

Continuous Metal Framing at 24 in. on center horizontally

1.0 in.

R-0.0

U-0.414

U-0.359

U-0.318

1.0 in.

R-3.8

U-0.325

U-0.290

U-0.263

1.0 in.

R-5.0

U-0.314

U-0.281

U-0.255

1.0 in.

R-6.5

U-0.305

U-0.274

U-0.249

1.5 in.

R-11.0

U-0.267

U-0.243

U-0.223

2.0 in.

R-7.6

U-0.230

U-0.212

U-0.197

2.0 in.

R-10.0

U-0.219

U-0.202

U-0.188

2.0 in.

R-13.0

U-0.210

U-0.195

U-0.182

3.0 in.

R-11.4

U-0.178

U-0.167

U-0.157

3.0 in.

R-15.0

U-0.168

U-0.158

U-0.149

3.0 in.

R-19.0

U-0.161

U-0.152

U-0.144

3.5 in.

R-11.0

U-0.168

U-0.158

U-0.149

3.5 in.

R-13.0

U-0.161

U-0.152

U-0.144

3.5 in.

R-15.0

U-0.155

U-0.147

U-0.140

4.5 in.

R-17.1

U-0.133

U-0.126

U-0.121

4.5 in.

R-22.5

U-0.124

U-0.119

U-0.114

4.5 in.

R-25.2

U-0.122

U-0.116

U-0.112

5.0 in.

R-19.0

U-0.122

U-0.117

U-0.112

5.0 in.

R-25.0

U-0.115

U-0.110

U-0.106

5.0 in.

R-28.0

U-0.112

U-0.107

U-0.103

5.0 in.

R-32.0

U-0.109

U-0.105

U-0.101

5.5 in.

R-19.0

U-0.118

U-0.113

U-0.109

5.5 in.

R-20.9

U-0.114

U-0.109

U-0.105

5.5 in.

R-21.0

U-0.113

U-0.109

U-0.105

5.5 in.

R-27.5

U-0.106

U-0.102

U-0.099

5.5 in.

R-30.8

U-0.104

U-0.100

U-0.096

6.0 in.

R-22.8

U-0.106

U-0.102

U-0.098

6.0 in.

R-30.0

U-0.099

U-0.095

U-0.092

6.0 in.

R-33.6

U-0.096

U-0.093

U-0.090

6.5 in.

R-24.7

U-0.099

U-0.096

U-0.092

7.0 in.

R-26.6

U-0.093

U-0.090

U-0.087

7.5 in.

R-28.5

U-0.088

U-0.085

U-0.083

8.0 in.

R-30.4

U-0.083

U-0.081

U-0.079

AE-24 2018 Washington State Energy Code

TABLE A103.3.7.1(4) – continued

DEFAULT U-FACTORS FOR CONCRETE AND MASONRY WALLS

Framing Type

and Depth

Rated R-Value of

Insulation Alone

Assembly U-Factors

for Solid Concrete

Walls

Assembly U-Factors

for Concrete Block

Walls:

Solid Grouted

Assembly U-Factors for

Concrete Block Walls:

Partially Grouted

(cores uninsulated

except where specified)

1 in Metal Clips at 24 in. on center horizontally and 16 in. vertically

(also, where allowed by Section C402.1.3, for assemblies with a ratio of metal penetration area/ mass wall area of <0.0004 or <0.04% of

the mass wall area)

1.0 in.

R-3.8

U-0.210

U-0.195

U-0.182

1.0 in.

R-5.0

U-0.184

U-0.172

U-0.162

1.0 in.

R-5.6

U-0.174

U-0.163

U-0.154

1.5 in.

R-5.7

U-0.160

U-0.151

U-0.143

1.5 in.

R-7.5

U-0.138

U-0.131

U-0.125

1.5 in.

R-8.4

U-0.129

U-0.123

U-0.118

2.0 in.

R-7.6

U-0.129

U-0.123

U-0.118

2.0 in.

R-10.0

U-0.110

U-0.106

U-0.102

2.0 in.

R-11.2

U-0.103

U-0.099

U-0.096

2.5 in.

R-9.5

U-0.109

U-0.104

U-0.101

2.5 in.

R-12.5

U-0.092

U-0.089

U-0.086

2.5 in.

R-14.0

U-0.086

U-0.083

U-0.080

3.0 in.

R-11.4

U-0.094

U-0.090

U-0.088

3.0 in.

R-15.0

U-0.078

U-0.076

U-0.074

3.0 in.

R-16.8

U-0.073

U-0.071

U-0.069

3.5 in.

R-13.3

U-0.082

U-0.080

U-0.077

3.5 in.

R-17.5

U-0.069

U-0.067

U-0.065

3.5 in.

R-19.6

U-0.064

U-0.062

U-0.061

4.0 in.

R-15.2

U-0.073

U-0.071

U-0.070

4.0 in.

R-20.0

U-0.061

U-0.060

U-0.058

4.0 in.

R-22.4

U-0.057

U-0.056

U-0.054

5.0 in.

R-28.0

U-0.046

U-0.045

6.0 in.

R-33.6

U-0.039

U-0.038

7.0 in.

R-39.2

U-0.034

U-0.033

8.0 in.

R-44.8

U-0.030

U-0.029

9.0 in.

R-50.4

U-0.027

U-0.026

10.0 in.

R-56.0

U-0.024

11.0 in.

R-61.6

U-0.022

Continuous Insulation Uninterrupted by Framing

No Framing

R-1.0

U-0.425

U-0.367

U-0.324

R-2.0

U-0.298

U-0.269

U-0.245

R-3.0

U-0.230

U-0.212

U-0.197

R-4.0

U-0.187

U-0.175

U-0.164

R-5.0

U-0.157

U-0.149

U-0.141

2018 Washington State Energy Code AE-25

TABLE A103.3.7.1(2) – continued

DEFAULT U-FACTORS FOR CONCRETE AND MASONRY WALLS

Framing Type

and Depth

Rated R-Value of

Insulation Alone

Assembly U-Factors

for Solid Concrete

Walls

Assembly U-Factors

for Concrete Block

Walls:

Solid Grouted

Assembly U-Factors for

Concrete Block Walls:

Partially Grouted

(cores uninsulated

except where specified)

No Framing

R-6.0

U-0.136

U-0.129

U-0.124

R-7.0

U-0.120

U-0.115

U-0.110

R-8.0

U-0.107

U-0.103

U-0.099

R-9.0

U-0.097

U-0.093

U-0.090

R-10.0

U-0.088

U-0.085

U-0.083

No Framing

R-11.0

U-0.081

U-0.079

U-0.076

R-12.0

U-0.075

U-0.073

U-0.071

R-13.0

U-0.070

U-0.068

U-0.066

R-14.0

U-0.065

U-0.064

U-0.062

R-15.0

U-0.061

U-0.060

U-0.059

No Framing

R-16.0

U-0.058

U-0.056

U-0.055

R-17.0

U-0.054

U-0.053

U-0.052

R-18.0

U-0.052

U-0.051

U-0.050

R-19.0

U-0.049

U-0.048

U-0.047

R-20.0

U-0.047

U-0.046

U-0.045

No Framing

R-21.0

U-0.045

U-0.044

U-0.043

R-22.0

U-0.043

U-0.042

R-3.0

U-0.041

U-0.040

R-24.0

U-0.039

U-0.038

R-25.0

U-0.038

U-0.037

No Framing

R-30.0

U-0.032

U-0.031

R-35.0

U-0.028

U-0.027

R-40.0

U-0.024

R-45.0

U-0.022

U-0.021

R-50.0

U-0.019

R-55.0

U-0.018

R-60.0

U-0.016

Brick cavity wall with continuous insulation

No Framing

R-0.0

U-0.337

U-0.299

U-0.270

No Framing

R-3.8

U-0.148

U-0.140

U-0.133

No Framing

R-5.0

U-0.125

U-0.120

U-0.115

No Framing

R-6.5

U-0.106

U-0.102

U-0.098

No Framing

R-7.6

U-0.095

U-0.091

U-0.088

No Framing

R-10.0

U-0.077

U-0.075

U-0.073

No Framing

R-10.5

U-0.079

U-0.077

U-0.075

No Framing

R-11.4

U-0.070

U-0.068

U-0.066

No Framing

R-15.0

U-0.056

U-0.055

U-0.053

No Framing

R-16.5

U-0.054

U-0.053

U-0.052

No Framing

R-19.0

U-0.046

U-0.045

U-0.044

No Framing

R-22.5

U-0.041

U-0.040

U-0.039

No Framing

R-28.5

U-0.033

U-0.032

AE-26 2018 Washington State Energy Code

TABLE A103.3.7.1(2) – continued

DEFAULT U-FACTORS FOR CONCRETE AND MASONRY WALLS

Framing Type

and Depth

Rated R-Value of

Insulation Alone

Assembly U-Factors

for Solid Concrete

Walls

Assembly U-Factors

for Concrete Block

Walls:

Solid Grouted

Assembly U-Factors for

Concrete Block Walls:

Partially Grouted

(cores uninsulated

except where specified)

Continuous Insulation Uninterrupted by Framing with Stucco and Continuous Metal Framing at 24 in. on center horizontally

1.0 in.

R-0.0 + R-19 c.i.

U-0.047

U-0.046

U-0.045

1.0 in.

R-3.8 + R-19 c.i.

U-0.045

U-0.044

1.0 in.

R-5.0 + R-19 c.i.

U-0.045

U-0.044

U-0.043

1.0 in.

R-6.5 + R-19 c.i.

U-0.045

U-0.044

U-0.043

1.5 in.

R-11.0 + R-19 c.i.

U-0.044

U-0.043

2.0 in.

R-7.6 + R-19 c.i.

U-0.043

U-0.042

U-0.041

2.0 in.

R-10.0 + R-19 c.i.

U-0.042

U-0.041

2.0 in.

R-13.0 + R-19 c.i.

U-0.042

U-0.041

3.0 in.

R-11.4 + R-19 c.i.

U-0.041

U-0.040

U-0.039

3.0 in.

R-15.0 + R-19 c.i.

U-0.040

U-0.039

3.0 in.

R-19.0 + R-19 c.i.

U-0.040

U-0.039

U-0.038

3.5 in.

R-11.0 + R-19 c.i.

U-0.040

U-0.039

3.5 in.

R-13.0 + R-19 c.i.

U-0.040

U-0.039

U-0.038

5.0 in.

R-19.0 + R-19 c.i.

U-0.037

U-0.036

5.0 in.

R-25.0 + R-19 c.i.

U-0.036

U-0.035

5.0 in.

R-32.5 + R-19 c.i.

U-0.035

U-0.034

5.5 in.

R-19.0 + R-19 c.i.

U-0.036

U-0.035

5.5 in.

R-21.0 + R-19 c.i.

U-0.035

Notes for Default Table A103.3.7.1(1):

a. It is acceptable to use the U-factors in Table A103.3.7.1(2) for all concrete and masonry walls, provided that the grouting is equal to or

less than that specified.

 -For ungrouted walls, use the partially grouted column.

 -For metal studs and z-furring, use the continuous-metal-framing category.

 -For discontinuous metal clips 1 inch square or smaller, use the metal-clip category.

 -For insulation that is attached without any framing members (e.g. glued), use the continuous-insulation uninterrupted-by-framing

category. Continuous insulation may be installed on the interior or exterior of masonry walls, or between stand-alone walls in

multilayer masonry walls, or on the interior or exterior of the concrete.

b. For Table A103.3.7.1(2), the U-factor includes R-0.17 for exterior air film and R-0.68 for interior air film-vertical surfaces. For insulated

walls, the U-factor also includes R-0.45 for 0.5 in. gypsum board. U-factors are provided for the following configurations:

1. Concrete wall: 8-in. normal weight concrete wall with a density of 145 lb/ft

2. Solid grouted concrete block wall: 8-in. medium weight ASTM C90 concrete block with a density of 115 lb/ft

and solid grouted

cores.

3. Partially grouted concrete block wall: 8-in. medium weight ASTM C90 concrete block with a density of 115 lb/ft

having

reinforcing steel every 32 in. vertically and every 48 in. horizontally, with cores grouted in those areas only. Other cores are filled

with insulating material only if there is no other insulation.

c. For walls with insulation contained in a framing layer, the U-factors in Table A103.3.7.1(4) assume contact (and thermal bridging)

between the mass wall and other framing. For wall assemblies with multiple layers where the wood or metal framing layer does not

contact the concrete or masonry layer (i.e., walls with an airspace between the stud wall layer and the mass wall layer), it is acceptable to

use the appropriate wood or metal frame wall default U-factors in Tables A103.3.1 or A103.3.6.1. Note: It is acceptable to use this

approach where the insulation extends beyond the framing and is in contact with the mass wall layer (e.g. a nominal four-inch metal stud

containing insulation that is nominally six inches thick and therefore extends two inches beyond the back of the metal stud).

d. Except for wall assemblies qualifying for note 3, if not taken from Table A103.3.7.1(2), mass wall U-factors shall be determined in

accordance with ASHRAE 90.1, Appendix A, Section A3.1 and Tables A3.1A to A3.1D, or Section A9.4.

2018 Washington State Energy Code AE-27

TABLE A103.3.7.2

DEFAULT U-FACTORS FOR PERIPHERAL EDGES OF INTERMEDIATE CONCRETE FLOORS

Slab Edge Treatment

Average Thickness of Wall Above and Below

6 inches

8 inches

10 inches

12 inches

Exposed Concrete

0.816

0.741

0.678

0.625

R-5 Exterior Insulation

0.161

0.157

0.154

0.152

R-6 Exterior Insulation

0.138

0.136

0.134

0.132

R-7 Exterior Insulation

0.122

0.120

0.118

0.116

R-8 Exterior Insulation

0.108

0.107

0.106

0.104

R-9 Exterior Insulation

0.098

0.097

0.095

0.094

R-10 Exterior Insulation

0.089

0.088

0.087

0.086

R-11 Exterior Insulation

0.082

0.081

0.080

0.079

R-12 Exterior Insulation

0.076

0.075

0.074

R-13 Exterior Insulation

0.070

0.069

0.068

R-14 Exterior Insulation

0.066

0.065

0.064

R-15 Exterior Insulation

0.062

0.061

0.060

Notes for Table A103.3.7.2:

a. Exterior insulation values listed above are continuous R-values on the exterior side of the concrete floor.

b. For conditions with an exterior wall above the peripheral edge of intermediate concrete floor but with no wall below the

intermediate concrete floor this table may be used as long as the code minimum insulation is applied to the floor slab below the

concrete floor.

c. Typical conditions where conditioned space building envelope wall thermal insulation values are broken concrete floors include, but

are not limited to, the following examples:

1. Elevator hoistway shafts that serve the conditioned building and pass through unconditioned floors such as parking garage

levels;

2. Stairwell enclosures that serve the conditioned building and pass through unconditioned floors such as parking garage

levels;

3. Walls between interior and exterior building envelope that separate the interior conditioned space from an exterior

courtyard or roofdeck;

4. Walls between interior and exterior building envelope that separate the interior conditioned space from an exterior

unconditioned space on parking garage levels.

SECTION A104

BELOW-GRADE WALLS AND SLABS

A104.1 General. Table A104.1 lists heat loss

coefficients for below-grade walls and floors.

Coefficients for below-grade walls are given as U-

factors (Btu/h  ft

 °F of wall area). Coefficients

for below-grade slabs are listed as F-factors

(Btu/h  ft  °F per lineal foot of slab perimeter).

Below-grade wall U-factors are only valid when

used with the accompanying below-grade slab

F-factor, and vice versa.

A104.2 Component description. All below-grade

walls are assumed to be 8 inch concrete. The wall is

assumed to extend from the slab upward to the top of

the mud sill for the distance specified in Table

A104.1, with 6 inches of concrete wall extending

above grade.

Interior insulation is assumed to be fiberglass batts

placed in the cavity formed by 2 x 4 framing on 24

inch centers with 1/2 inch gypsum board as the

interior finish material. Exterior insulation is

assumed to be applied directly to the exterior of the

below-grade wall from the top of the wall to the

footing. The exterior case does not assume any

interior framing or sheetrock.

In all cases, the entire wall surface is assumed to be

insulated to the indicated nominal level with the

appropriate framing and insulation application.

Coefficients are listed for wall depths of 2, 3-1/2 and

7 feet below grade. Basements shallower than two

feet should use on-grade slab coefficients.

Heat-loss calculations for wall areas above-grade

should use above-grade wall U-factors, beginning at

the mudsill.

AE-28 2018 Washington State Energy Code

TABLE A104.1

DEFAULT WALL U-FACTORS AND SLAB F-FACTORS FOR BASEMENTS

Below Grade Wall

U-factor

Below Grade Slab

F-factor

2 Foot Depth Below Grade

Uninsulated

0.331

0.58

R-11 Interior

0.063

0.67

R-11 Interior w/TB

0.065

0.59

R-19 Interior

0.042

0.68

R-19 Interior w/TB

0.045

0.59

R-21 Interior

0.040

0.68

R-21 Interior w/TB

0.042

0.59

R-21+R-5 Interior

0.031

0.68

R-21+R-5 Interior w/TB

0.032

0.59

R-21+R-7 Interior

0.029

0.68

R-21+R-7 Interior w/TB

0.030

0.59

R-10 Exterior

0.089

0.56

R-12 Exterior

0.061

0.60

3.5 Foot Depth Below Grade

Uninsulated

0.271

0.51

R-11 Interior

0.058

0.61

R-11 Interior w/TB

0.061

0.55

R-19 Interior

0.041

0.62

R-19 Interior w/TB

0.042

0.55

R-21 Interior

0.038

0.63

R-21 Interior w/TB

0.040

0.56

R-21+R-5 Interior

0.030

0.632

R-21+R-5 Interior w/TB

0.031

0.56

R-21+R-7 Interior

0.027

0.63

R-21+R-7 Interior w/TB

0.029

0.56

R-10 Exterior

0.075

0.52

R-12 Exterior

0.057

0.57

7 Foot Depth Below Grade

Uninsulated

0.185

0.43

R-11 Interior

0.051

0.541

R-11 Interior w/TB

0.053

0.49

R-19 Interior

0.036

0.54

R-19 Interior w/TB

0.037

0.50

R-21 Interior

0.035

0.56

R-21 Interior w/TB

0.035

0.50

R-21+R-5 Interior

0.027

0.56

R-21+R-5 Interior w/TB

0.028

0.51

R-21+R-7 Interior

0.025

0.57

R-21+R-7 Interior w/TB

0.026

0.51

R-10 Exterior

0.058

0.47

R-12 Exterior

0.050

0.42

TB = Thermal Break

2018 Washington State Energy Code AE-29

A104.3 Insulation description. Coefficients are

listed for the following four configurations:

1. Uninsulated: No insulation or interior finish.

2. Interior insulation: Interior 2 x 4 insulated

wall without a thermal break between concrete

wall and slab.

3. Interior insulation with thermal break:

Interior 2 x 4 insulated wall with R-5 rigid

board providing a thermal break between the

concrete wall and the slab.

4. Exterior insulation: Insulation applied

directly to the exterior surface of the concrete

wall.

SECTION A105

FLOORS OVER UNCONDITIONED SPACE

A105.1 General. Tables A105.1(1), A105.1(2) and

A105.1(3) list heat loss coefficients for floors over

unconditioned spaces in units of Btu/h  ft

 °F.

They are derived from procedures listed in the

ASHRAE Fundamentals Handbook, assuming an

average outdoor temperature of 45°F, an average

indoor temperature of 65°F and a crawlspace area of

1350 ft

and 100 feet of perimeter. The crawlspace is

assumed to be 2.5 feet high, with 24 inches below

grade and 6 inches above grade.

AE-30 2018 Washington State Energy Code

TABLE A105.1(1)

DEFAULT U-FACTORS FOR WOOD-FRAMED FLOORS OVER

VENTED CRAWLSPACE OR UNHEATED BASEMENT

Nominal R-Value

U-Factor

Floor

Perimeter

Post &

Beam

Joists

0.112

0.134

0.100

0.116

0.098

0.114

0.093

0.107

0.052

0.056

0.048

0.052

0.038

0.041

0.036

0.038

0.034

0.037

0.033

0.035

0.032

0.034

0.031

0.033

0.028

0.029

0.027

0.028

0.024

0.025

0.024

TABLE A105.1(2)

DEFAULT U-FACTORS FOR WOOD-FRAMED FLOORS OVER

HEATED PLENUM CRAWLSPACES

Nominal R-Value

Perimeter

U-Factor

0.085

0.075

0.069

Note: Crawlspaces used as heated plenums have approximately 30% higher heat loss rate than unvented

crawlspaces with the same assumed ACH. Default U-factors in Table A105.1(2) reflect this higher rate of

heat loss.

TABLE A105.1(3)

DEFAULT U-FACTORS FOR EXPOSED FLOORS

U-Factor

Nominal

R-Value

Concrete

Wood Joist

Metal Joist

R-11

0.077

0.088

0.14

R-15

0.059

0.076

0.12

R-19

0.048

0.062

0.11

R-21

0.043

0.057

0.11

R-25

0.037

0.051

0.10

R-30

0.031

0.040

0.09

R-38

0.025

0.034

0.08

2018 Washington State Energy Code AE-31

A105.2 Crawlspace description. Four

configurations are considered: Naturally ventilated

crawlspace, mechanically vented crawlspace, heated

plenum crawlspace and exposed floor.

A105.2.1 Naturally ventilated crawlspaces.

Assumed to have 3.0 air changes per hour, with at

least 1.0 ft

of net-free ventilation in the foundation

for every 300 ft

of crawlspace floor area. The

crawlspace is not actively heated. Floors over

unheated areas, such as garages, may only use those

values which have R-0 perimeter insulation.

A105.2.2 Mechanically ventilated crawlspaces.

Assume to have 1.5 air changes per hour, with less

than 1.0 ft

of net-free ventilation in the foundation

for every 300 ft

of crawlspace floor area. The

crawlspace is not actively heated. Floors over

unheated basements may only use those values which

have R-0 perimeter insulation.

A105.2.3 Heated plenum crawlspaces. Assumed to

have 0.25 air changes per hour, with no foundation

vents. Heated supply air from central furnace is

blown into a crawlspace and allowed to enter the

living space unducted via holes cut into the floor.

A105.2.4 Exposed floors. Assumes no buffer space,

and a covering of 1/2 inch T1-11 on the exterior of

the cavity exposed to the outside air or rigid

insulation below a concrete floor, such as over

parking garages.

A105.3 Construction description. Floors are

assumed to be either joisted floors framed on 16 inch

centers, or post and beam on 4 foot by 8 foot squares.

Insulation is assumed to be installed under the

subflooring between the joists or beams with no

space between the insulation and the subfloor.

Insulation is assumed to be uncompressed. Exposed

floors also include concrete with continuous rigid

insulation assumed.

Perimeter insulation is assumed to extend from the

top of the rim joist to the crawlspace floor and then

inward along the ground (on top of the ground cover)

for at least 24 inches.

Floor coverings are assumed to be light carpet with

rubber pad.

SECTION A106

ON-GRADE SLAB FLOORS

A106.1 General. Table A106.1 lists heat loss

coefficients for heated on-grade slab floors, in units

of Btu/h  °F per lineal foot of perimeter.

TABLE A106.1

DEFAULT F-FACTORS FOR ON-GRADE SLABS

Insulation type

R-0

R-5

R-10

R-15

Unheated Slab

Uninsulated slab

0.73

2 ft Horizontal (No thermal break)

0.70

0.69

4 ft Horizontal (No thermal break)

0.67

0.64

0.63

2 ft Vertical

0.58

0.54

0.52

4 ft Vertical

0.54

0.48

0.45

Fully insulated slab

0.36

Heated Slab

Uninsulated slab

0.84

Fully insulated slab

0.74

0.55

0.44

R-5 Center (With perimeter insulation)

0.66

0.62

R-10 Center (With perimeter insulation)

0.51

3 ft Vertical

0.78

AE-32 2018 Washington State Energy Code

A106.2 Component description. All on-grade slab

floors are assumed to be 6 inch concrete poured

directly onto the earth. The bottom of the slab is

assumed to be at grade line. Monolithic and floating

slabs are not differentiated.

Soil is assumed to have a conductivity of 0.75

Btu/h  ft

 °F. Slabs 2 feet or more below grade

should use basement coefficients.

A106.3 Insulation description. Coefficients are

provided for the following three configurations:

1. Two foot (or four foot) vertical: Insulation is

applied directly to the slab exterior, extending

downward from the top of the slab to a depth

of 2 feet (or 4 feet) below grade.

2. Two foot (or four foot) horizontal:

Insulation is applied directly to the underside

of the slab, and run horizontally from the

perimeter inward for 2 feet (or 4 feet). The

slab edge is exposed in this configuration.

Note: A horizontal installation with a

thermal break of at least R-5 at the slab

edge should use the vertical-case F-

factors.

3. Fully insulated slab: Insulation extends from

the top of the slab, along the entire perimeter,

and completely covers the area under the slab.

Thicker perimeter insulation covers the slab

edge and extends 2 feet under the slab.

SECTION A107

DEFAULT U-FACTORS FOR DOORS

A107.1 Doors without NFRC certification. Doors

that do not have NFRC certification shall be assigned

the appropriate U-factor from Tables A107.1(1)

through A107.1(4).

2018 Washington State Energy Code AE-33

TABLE A107.1(1)

DEFAULT U-FACTORS FOR DOORS

Door Type

No Glazed

Fenestration

Single

Glazing

Double

Glazing

with

¼ in.

Airspace

Double

Glazing

with

½ in.

Airspace

Double

Glazing

with

e=0.10,

½ in.

Argon

SWINGING DOORS (Rough opening – 38 in. x 82 in.)

Slab Doors

Wood slab in wood frame

0.46

6% glazed fenestration (22 in. x 8 in. lite)

–

0.48

0.47

0.46

0.44

25% glazed fenestration (22 in.x36 in. lite)

–

0.58

0.48

0.46

0.42

45% glazed fenestration (22 in.x64 in. lite)

–

0.69

0.49

0.46

0.39

More than 50% glazed fenestration

Use Table C303.1.3(1)/R303.1.3(1) as appropriate

Insulated steel slab with wood edge in wood

frame

0.16

6% glazed fenestration (22 in. x 8 in. lite)

–

0.21

0.20

0.19

0.18

25% glazed fenestration (22 in.x36 in. lite)

–

0.39

0.28

0.26

0.23

45% glazed fenestration (22 in.x64 in. lite)

–

0.58

0.38

0.35

0.26

More than 50% g glazed fenestration

Use Table C303.1.3(1)/R303.1.3(1) as appropriate

Foam insulated steel slab with metal edge in

steel frame

0.37

6% glazed fenestration (22 in. x 8 in. lite)

–

0.44

0.42

0.41

0.39

25% glazed fenestration (22 in.x36 in. lite)

–

0.55

0.50

0.48

0.44

45% glazed fenestration (22 in.x64 in. lite)

–

0.71

0.59

0.56

0.48

More than 50% glazed fenestration

Use Table C303.1.3(1)/R303.1.3(1) as appropriate

Cardboard honeycomb slab with metal edge in

steel frame

0.61

Style and Rail Doors

Sliding glass doors/French doors

Use Table C303.1.3(1)/R303.1.3(1) as appropriate

Site-Assembled Style and Rail Doors

Aluminum in aluminum frame

–

1.32

0.99

0.93

0.79

Aluminum in aluminum frame with

thermal break

–

1.13

0.80

0.74

0.63

a. Thermally broken sill (add 0.03 for non-thermally broken sill)

b. Non-thermally broken sill

c. Nominal U-factors are through the center of the insulated panel before consideration of thermal bridges

around the edges of the door section and due to the frame.

AE-34 2018 Washington State Energy Code

TABLE A107.1(2)

DEFAULT U-FACTORS FOR REVOLVING DOORS

Revolving Doors

Size (W x H)

U-Factor

3-wing

8 ft x 7 ft

0.79

10 ft x 8 ft

0.80

4-wing

7 ft x 6.5 ft

0.63

7 ft x 7.5 ft

0.64

Open

82 in x 84 in

1.32

TABLE A107.1(3)

DEFAULT U-FACTORS FOR STEEL EMERGENCY DOORS

Double-Skin Steel Emergency Exit Doors

Core Insulation

3 ft x 6 ft 8 in

6 ft x 6 ft 8 in

1-3/8 in. thickness

Honeycomb kraft paper

Mineral wool, steel ribs

Polyurethane foam

0.57

0.44

0.34

0.52

0.36

0.28

1-3/4 in. thickness

Honeycomb kraft paper

Mineral wool, steel ribs

Polyurethane foam

0.57

0.41

0.31

0.54

0.33

0.26

1-3/8 in. thickness

Honeycomb kraft paper

Mineral wool, steel ribs

Polyurethane foam

0.60

0.47

0.37

0.55

0.39

0.31

1-3/4 in. thickness

Honeycomb kraft paper

Mineral wool, steel ribs

Polyurethane foam

0.60

0.44

0.34

0.57

0.37

0.30

2018 Washington State Energy Code AE-35

TABLE A107.1(4)

DEFAULT U-FACTORS FOR STEEL GARAGE AND HANGAR DOORS

Double-Skin Steel Garage and Aircraft Hangar Doors

Insulation

One-piece tilt-up

Sectional tilt-

Aircraft hangar

8 ft. x 7 ft.

16 ft. x 7 ft.

9 ft. x 7 ft.

72 ft. x 12 ft.

240 ft. x 50 ft.

1-3/8 in. thickness

EPS, steel ribs

XPS, steel ribs

0.36

0.33

0.31

0.34-0.39

0.31-0.36

2 in. thickness

EPS, steel ribs

XPS, steel ribs

0.31

0.29

0.28

0.26

0.29-0.33

0.27-0.31

3 in. thickness

EPS, steel ribs

XPS, steel ribs

0.26

0.24

0.23

0.21

0.25-0.28

0.24-0.27

4 in. thickness

EPS, steel ribs

XPS, steel ribs

0.23

0.21

0.20

0.19

0.23-0.25

0.21-0.24

6 in. thickness

EPS, steel ribs

XPS, steel ribs

0.20

0.19

0.16

0.15

0.20-0.21

0.19-0.21

4 in. thickness

Non-insulated

Expanded polystyrene

Mineral wool, steel ribs

Extruded polystyrene

1.10

0.25

0.23

1.23

0.16

0.15

6 in. thickness

Non-insulated

Expanded polystyrene

Mineral wool, steel ribs

Extruded polystyrene

1.10

0.21

0.23

0.20

1.23

0.13

0.12

Uninsulated

All products

1.15

a. Values are for thermally broken or thermally unbroken doors.

b. Lower values are for thermally broken doors; upper values are for doors with no thermal break.

c. Typical size for a small private airplane (single-engine or twin).

d. Typical hangar door for a midsize commercial jet airliner.

e. EPS is extruded polystyrene, XPS is expanded polystyrene.

AE-36 2018 Washington State Energy Code

SECTION A108

AIR INFILTRATION

A108.1 General. Tables A108.1(1) and A108.1(2)

list effective air change rates and heat capacities for

heat loss due to infiltration for Single-Family

Residential.

The estimated seasonal average infiltration rate in

air changes per hour (ACH) is given for standard air-

leakage control (see Section R402.4 for air leakage

requirements for Single-Family Residential). The

effective air change rate shall be used in calculations

for compliance under either the Component

Performance or Systems Analysis approaches.

Heat loss due to infiltration shall be computed

using the following equation:

infil

= ACH

eff

* HCP

Where:

infil

= Heat loss due to air infiltration.

ACH

eff

= The effective air infiltration rate in

Table A108.1(1)

HCP = The Heat Capacity Density

Product for the appropriate

elevation or climate zone as given

below.

TABLE A108.1(1)

ASSUMED EFFECTIVE AIR CHANGES

PER HOUR

Air-Leakage

Control Package

Air Changes per Hour

Natural Effective

Standard

0.35 0.35

TABLE A108.1(2)

DEFAULT HEAT CAPACITY/DENSITY

PRODUCT FOR AIR

Zone

Average

Elevation

Heat Capacity/

Density

Mean Sea Level

0.0180 Btu/h°F

2000

0.0168 Btu/h°F

3000

0.0162 Btu/h°F

2018 Washington State Energy Code AE-37

Appendix B

DEFAULT INTERNAL LOAD VALUES AND SCHEDULES

SECTION B101

GENERAL

B101.1 Scope. The following default internal load values and schedules shall apply to Section C407.

SECTION B102

DEFAULT TABLES OF INTERNAL LOADS

B102 Default tables of internal loads. Default occupancy densities, receptacle power densities and service hot

water consumption are included in Table B102.

TABLE B102

ACCEPTABLE OCCUPANCY DENSITIES, RECEPTACLE POWER DENSITIES

AND SERVICE HOT WATER CONSUMPTION

Building Type

Occupancy Density

/Person (Btu/h· ft

)

Receptacle Power

Density

, Watts/ ft

(Btu/h· ft

)

Service Hot Water

Quantities

Btu/h per person

Assembly

50 (4.60)

0.25 (0.85)

215

Health/Institutional

200 (1.15)

1.00 (3.41)

135

Hotel/Motel

250 (0.92)

0.25 (0.85)

1,110

Light Manufacturing

750 (0.31)

0.20 (0.68)

225

Office

275 (0.84)

0.75 (2.56)

175

Parking Garage

Restaurant

100 (2.30)

0.10 )0.34)

390

Retail

300 (0.77)

0.25 (0.85)

135

School

75 (3.07)

0.50 (1.71)

215

Warehouse

15,000 (0.02)

0.10 (0.34)

225

a. The occupancy densities, receptacle power densities, and service hot water consumption values

are from ASHRAE Standard 90.1-1989 and addenda.

b. Values are in square feet of conditioned floor area per person. Heat generation in Btu per

person per hour is 230 sensible and 190 latent. Figures in parenthesis are equivalent Btu per

hour per square foot.

c. Values are in Watts per square foot of conditioned floor area. Figures in parenthesis are

equivalent Btu per hour per square foot. These values are the minimum acceptable. If other

process loads are not input (such as for computers, cooking, refrigeration, etc.), it is

recommended that receptacle power densities be increased until total process energy

consumption is equivalent to 25% of the total.

d. Values are in Btu per person per hour.

AE-38 2018 Washington State Energy Code

SECTION B103

DEFAULT SCHEDULES

B103 Default schedules. Default schedules for occupancy, lighting, receptacles, HVAC, service hot water, and

elevators are included in Tables B103(1) through B103(10).

TABLE B103(1)

ASSEMBLY OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

Off

2 (1-2 am)

Off

3 (2-3 am)

Off

4 (3-4 am)

Off

5 (4-5 am)

Off

6 (5-6 am)

Off

7 (6-7 am)

8 (7-8 am)

9 (8-9 am)

10 (9-10 am)

11 (10-11 am)

12 (11-12 pm)

13 (12-1 pm)

14 (1-2 pm)

15 (2-3 pm)

16 (3-4 pm)

17 (4-5 pm)

18 (5-6 pm)

19 (6-7 pm)

20 (7-8 pm)

21 (8-9 pm)

22 (9-10 pm)

23 (10-11 pm)

24 (11-12 am)

Off

Total/Day

710

750

700

1155

800

845

1800

1700

125

115

Total/Week

50.50 hours

74.20 hours

124 hours

5.9 hours

0 hours

Total/Year

2633 hours

3869 hours

6465 hours

308 hours

0 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

2018 Washington State Energy Code AE-39

TABLE B103(2)

HEALTH OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

2 (1-2 am)

3 (2-3 am)

4 (3-4 am)

5 (4-5 am)

6 (5-6 am)

7 (6-7 am)

8 (7-8 am)

9 (8-9 am)

10 (9-10 am)

100

11 (10-11 am)

100

12 (11-12 pm)

100

13 (12-1 pm)

14 (1-2 pm)

100

15 (2-3 pm)

100

16 (3-4 pm)

100

17 (4-5 pm)

100

18 (5-6 pm)

100

19 (6-7 pm)

20 (7-8 pm)

21 (8-9 pm)

22 (9-10 pm)

23 (10-11 pm)

24 (11-12 am)

Total/Day

850

380

1060

550

160

2400

783

249

1136

540

Total/Week

46.70 hours

60.10 hours

168 hours

41.88 hours

62.36 hours

Total/Year

2435 hours

3134 hours

8760 hours

2148 hours

3251 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

AE-40 2018 Washington State Energy Code

TABLE B103(3)

HOTEL/MOTEL OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

2 (1-2 am)

3 (2-3 am)

4 (3-4 am)

5 (4-5 am)

6 (5-6 am)

7 (6-7 am)

8 (7-8 am)

9 (8-9 am)

10 (9-10 am)

11 (10-11 am)

12 (11-12 pm)

13 (12-1 pm)

14 (1-2 pm)

15 (2-3 pm)

16 (3-4 pm)

17 (4-5 pm)

18 (5-6 pm)

19 (6-7 pm)

20 (7-8 pm)

21 (8-9 pm)

22 (9-10 pm)

23 (10-11 pm)

24 (11-12 am)

Total/Day

1390

1300

855

785

810

2400

915

930

900

1217

1303

1287

Total/Week

96.40 hours

58.70 hours

168.0 hours

64.05 hours

86.75 hours

Total/Year

5026 hours

3061 hours

8760 hours

3340 hours

4523 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

2018 Washington State Energy Code AE-41

TABLE B103(4)

LIGHT MANUFACTURING OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

Off

2 (1-2 am)

Off

3 (2-3 am)

Off

4 (3-4 am)

Off

5 (4-5 am)

Off

6 (5-6 am)

Off

7 (6-7 am)

Off

8 (7-8 am)

Off

9 (8-9 am)

Off

10 (9-10 am)

Off

11 (10-11 am)

Off

12 (11-12 pm)

Off

13 (12-1 pm)

Off

14 (1-2 pm)

Off

15 (2-3 pm)

Off

16 (3-4 pm)

Off

17 (4-5 pm)

Off

18 (5-6 pm)

Off

19 (6-7 pm)

Off

20 (7-8 pm)

Off

21 (8-9 pm)

Off

22 (9-10 pm)

Off

23 (10-11 pm)

Off

24 (11-12 am)

Off

Total/Day

920

200

1040

280

120

1600

1200

537

256

113

555

151

Total/Week

48.60 hours

56.00 hours

92.00 hours

30.54 hours

29.26 hours

Total/Year

2534 hours

2920 hours

4797 hours

1592 hours

1526 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

AE-42 2018 Washington State Energy Code

TABLE B103(5)

OFFICE OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

Off

2 (1-2 am)

Off

3 (2-3 am)

Off

4 (3-4 am)

Off

5 (4-5 am)

Off

6 (5-6 am)

Off

7 (6-7 am)

Off

8 (7-8 am)

Off

9 (8-9 am)

Off

10 (9-10 am)

Off

11 (10-11 am)

Off

12 (11-12 pm)

Off

13 (12-1 pm)

Off

14 (1-2 pm)

Off

15 (2-3 pm)

Off

16 (3-4 pm)

Off

17 (4-5 pm)

Off

18 (5-6 pm)

Off

19 (6-7 pm)

Off

20 (7-8 pm)

Off

21 (8-9 pm)

Off

22 (9-10 pm)

Off

23 (10-11 pm)

Off

24 (11-12 am)

Off

Total/Day

920

200

1040

280

120

1600

1200

537

256

113

555

151

Total/Week

48.60 hours

56.00 hours

92.00 hours

30.54 hours

29.26 hours

Total/Year

2534 hours

2920 hours

4797 hours

1592 hours

1526 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

2018 Washington State Energy Code AE-43

TABLE B103(6)

PARKING GARAGE OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

100

2 (1-2 am)

100

3 (2-3 am)

100

4 (3-4 am)

100

5 (4-5 am)

100

6 (5-6 am)

100

7 (6-7 am)

100

8 (7-8 am)

100

9 (8-9 am)

100

10 (9-10 am)

100

11 (10-11 am)

100

Based on

likely use

Included with

other occupancies

12 (11-12 pm)

100

13 (12-1 pm)

100

14 (1-2 pm)

100

15 (2-3 pm)

100

16 (3-4 pm)

100

17 (4-5 pm)

100

18 (5-6 pm)

100

19 (6-7 pm)

100

20 (7-8 pm)

100

21 (8-9 pm)

100

22 (9-10 pm)

100

23 (10-11 pm)

100

24 (11-12 am)

100

Total/Day

2400

Total/Week

168 hours

Total/Year

8760 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

AE-44 2018 Washington State Energy Code

TABLE B103(7)

RESTAURANT OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

2 (1-2 am)

3 (2-3 am)

4 (3-4 am)

Off

5 (4-5 am)

Off

6 (5-6 am)

Off

7 (6-7 am)

Off

8 (7-8 am)

Off

9 (8-9 am)

Off

10 (9-10 am)

Off

11 (10-11 am)

12 (11-12 pm)

13 (12-1 pm)

14 (1-2 pm)

15 (2-3 pm)

16 (3-4 pm)

17 (4-5 pm)

18 (5-6 pm)

19 (6-7 pm)

20 (7-8 pm)

21 (8-9 pm)

22 (9-10 pm)

23 (10-11 pm)

24 (11-12 am)

Total/Day

750

740

485

1455

1365

1115

2000

1800

1700

790

730

625

Total/Week

49.75 hours

97.55 hours

135 hours

53.05 hours

0 hours

Total/Year

2594 hours

5086 hours

7039 hours

2766 hours

0 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

2018 Washington State Energy Code AE-45

TABLE B103(8)

RETAIL OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

Off

2 (1-2 am)

Off

3 (2-3 am)

Off

4 (3-4 am)

Off

5 (4-5 am)

Off

6 (5-6 am)

Off

7 (6-7 am)

Off

8 (7-8 am)

Off

9 (8-9 am)

10 (9-10 am)

11 (10-11 am)

12 (11-12 pm)

13 (12-1 pm)

14 (1-2 pm)

15 (2-3 pm)

16 (3-4 pm)

17 (4-5 pm)

18 (5-6 pm)

Off

19 (6-7 pm)

Off

20 (7-8 pm)

Off

21 (8-9 pm)

Off

22 (9-10 pm)

Off

23 (10-11 pm)

Off

24 (11-12 am)

Off

Total/Day

720

750

280

1115

985

525

1500

1600

900

662

690

459

844

761

288

Total/Week

46.30 hours

70.85 hours

100 hours

44.59 hours

52.69 hours

Total/Year

2414 hours

3694 hours

5214 hours

2325 hours

2747 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

AE-46 2018 Washington State Energy Code

TABLE B103(9)

SCHOOL OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

Off

2 (1-2 am)

Off

3 (2-3 am)

Off

4 (3-4 am)

Off

5 (4-5 am)

Off

6 (5-6 am)

Off

7 (6-7 am)

Off

8 (7-8 am)

Off

9 (8-9 am)

Off

10 (9-10 am)

Off

11 (10-11 am)

Off

12 (11-12 pm)

Off

13 (12-1 pm)

Off

14 (1-2 pm)

Off

15 (2-3 pm)

Off

16 (3-4 pm)

Off

17 (4-5 pm)

Off

18 (5-6 pm)

Off

19 (6-7 pm)

Off

20 (7-8 pm)

Off

21 (8-9 pm)

Off

22 (9-10 pm)

Off

23 (10-11 pm)

Off

24 (11-12 am)

Off

Total/Day

710

990

170

120

1500

500

691

285

Total/Week

36.00 hours

52.40 hours

80.00 hours

36.19 hours

14.25 hours

Total/Year

1877 hours

2732 hours

4171 hours

1887 hours

743 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

2018 Washington State Energy Code AE-47

TABLE B103(10)

WAREHOUSE OCCUPANCY

Hour of Day

(Time)

Schedule for

Occupancy

Schedule for

Lighting Receptacle

Schedule for

HVAC System

Schedule for

Service Hot Water

Schedule for

Elevator

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Percent of

Maximum Load

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

Sat

Sun

1 (12-1 am)

Off

2 (1-2 am)

Off

3 (2-3 am)

Off

4 (3-4 am)

Off

5 (4-5 am)

Off

6 (5-6 am)

Off

7 (6-7 am)

Off

8 (7-8 am)

Off

9 (8-9 am)

Off

10 (9-10 am)

Off

11 (10-11 am)

Off

12 (11-12 pm)

Off

13 (12-1 pm)

Off

14 (1-2 pm)

Off

15 (2-3 pm)

Off

16 (3-4 pm)

Off

17 (4-5 pm)

Off

18 (5-6 pm)

Off

19 (6-7 pm)

Off

20 (7-8 pm)

Off

21 (8-9 pm)

Off

22 (9-10 pm)

Off

23 (10-11 pm)

Off

24 (11-12 am)

Off

Total/Day

680

120

915

180

120

1000

800

429

Total/Week

35.20 hours

48.75 hours

58.00 hours

22.88 hours

3.50 hours

Total/Year

1835 hours

2542 hours

3024 hours

1193 hours

182 hours

Wk = Weekday

a. Schedules for occupancy, lighting, receptacle, HVAC system, and service hot water are from ASHRAE

Standard 90.1-1989 and addendums, except that 5% emergency lighting has been added for all off hours.

Elevator schedules, except for restaurants, are from the U.S. Department of Energy Standard Evaluation

Techniques except changed to 0% when occupancy is 0%. These values may be used only if actual

schedules are not known.

AE-48 2018 Washington State Energy Code

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2018 Washington State Energy Code AE-49

APPENDIX C

EXTERIOR DESIGN CONDITIONS

As required by Sections C302.2 and R302.2, the heating or cooling outdoor design temperatures shall be selected

from Table C-1.

TABLE C-1

OUTDOOR DESIGN TEMPERATURES

Location

Outdoor

Design Temp

Heating (°F)

Outdoor

Design Temp

Cooling (°F)

Aberdeen 20NNE

Anacortes

Anatone

-4

Auburn

Battleground

Bellevue

Bellingham 2N

Blain

Bremerton

Burlington

Chehalis

Chelan

Cheney

Chesaw

-11

Clarkston

Cle Elum

Colfax 1NW

Colville AP

-2

Concrete

Connell 4NNW

100

Cougar 5E

Dallesport AP

Darrington RS

Davenport

Edmonds

Ellensburg AP

Elma

Ephrata AP

Everett Paine AFB

Forks 1E

Glacier RS

Glenoma (Kosmos)

Goldendale

Grays River Hatchery

Location

Outdoor

Design Temp

Heating (°F)

Outdoor

Design Temp

Cooling (°F)

Greenwater

1.4

Grotto

Hoquiam AP

Inchelium 2NW

John Day Dam

100

Long Beach 3NNE

Longview

Lower Granite Dam

Lower Monument

Dam

103

Marysville

Metaline Falls

-1

Methow 2W

Nespelem 2S

-4

Newhalem

Newport

-5

Northport

Oak Harbor

Odessa

100

Olga 2SE

Olympia AP

Omak 2NW

Oroville

Othello

Packwood

Plain

-3

Pleasant View

Pomeroy

Port Angeles

Port Townsend

Prosser

Puyallup

Quilcene 2SW

Quinault RS

AE-50 2018 Washington State Energy Code

Location

Outdoor

Design Temp

Heating (°F)

Outdoor

Design Temp

Cooling (°F)

Rainier, Longmire

Paradise RS

Raymond

Redmond

Republic

-9

Richland

101

Ritzville

Satus Pass

Seattle: SeaTac AP

Sedro Woolley 1E

Sequim

Shelton

Smyrna

102

Snohomish

Snoqualmie Pass

Spokane AP

Spokane CO

Stampede Pass

Stehekin 3 NW

Stevens Pass

Tacoma CO

Tatoosh Island

Toledo AP

Vancouver

Vashon Island

Walla Walla AP

Waterville

Wellpinit

Wenatchee CO

Whidbey Island

Willapa Harbor

Wilson Creek

Winthrop 1WSW

-12

Yakima AP

ABBREVIATIONS: AFB Air Force Base AP Airport CO City Office RS Ranger Station

Typical: "4(miles)NE"

2018 Washington State Energy Code CE-51

APPENDIX D

CALCULATION OF HVAC TOTAL SYSTEM PERFORMANCE RATIO

D101 Scope. This appendix establishes criteria for demonstrating compliance using the HVAC total

system performance ratio (HVAC TSPR) for systems serving office, retail, library, and education

occupancies and buildings, which are subject to the requirements of Section C403.3.5 without exception.

Those HVAC systems shall comply with Section C403 and this appendix as required by Section

C403.1.1.

D201 Compliance. Compliance based on HVAC total system performance ratio requires that the

provisions of Section C403.3 are met and the HVAC total system performance ratio of the proposed

design is more than or equal to the HVAC total system performance ratio of the standard reference

design. The HVAC TSPR is calculated according to the following formula:

HVAC TSPR = annual heating and cooling load /annual carbon emissions from energy consumption of

the building HVAC systems

Where:

Annual carbon emissions from energy

consumption of the building HVAC

systems

sum of the annual carbon emissions in pounds for

heating, cooling, fans, energy recovery, pumps, and

heat rejection calculated by multiplying site energy

consumption by the carbon emission factors from

Table C407.1

Annual heating and cooling load

sum of the annual heating and cooling loads met by the

building HVAC system in thousands of Btus.

TABLE C407.1

CARBON EMISSIONS FACTORS

Type

CO2e (lb/unit)

Unit

Electricity

0.70

kWh

Natural gas

11.70

Therm

Oil

19.2

Gallon

Propane

10.5

Gallon

Other

195.00

mmBtu

On-site renewable energy

0.00

a. District energy systems may use alternative emissions factors supported by

calculations approved by the code official.

D300 Simulation Program

D301 General.

D302 Calculation of the HVAC TSPR for the Standard Reference Design. The simulation program

shall calculate the HVAC TSPR based only on the input for the proposed design and the requirements of

this appendix. The calculation procedure shall not allow the user to directly modify the building

component characteristics of the standard reference design.

D303 Specific approval. Performance analysis tools meeting the applicable subsections of Appendix D

and tested according to ASHRAE Standard 140 shall be permitted to be approved. Tools are permitted to

be approved based on meeting a specified threshold for a jurisdiction. The code official shall be permitted

to approve tools for a specified application or limited scope.

CE-52 2018 Washington State Energy Code

D400 Climatic data. The simulation program shall perform the simulation using hourly values of climatic

data, such as temperature and humidity, using TMY3 data for the site as specified here:

https://buildingenergyscore.energy.gov/resources

D500 Documentation. Documentation conforming to the provisions of this section shall be provided to

the code official.

D501 Compliance report. Building permit submittals shall include:

1. A report produced by the simulation software that includes the following:

1.1. Address of the building.

1.2. Name of individual completing the compliance report.

1.3. Name and version of the compliance software tool.

1.4. The dimensions, floor heights and number of floors for each block.

1.5. By block, the U-factor, C-factor, or F-factor for each simulated opaque envelope component

and the U-factor and SHGC for each fenestration component.

1.6. By block or by surface for each block, the fenestration area.

1.7. By block, a list of the HVAC equipment simulated in the proposed design including the

equipment type, fuel type, equipment efficiencies and system controls.

1.8. The HVAC total system performance ratio for both the standard reference design and the

proposed design.

2. A mapping of the actual building HVAC component characteristics and those simulated in the

proposed design showing how individual pieces of HVAC equipment identified above have been

combined into average inputs as required by Section D601.11 including:

2.1. Fans

2.2. Hydronic pumps

2.3. Air handlers

2.4. Packaged cooling equipment

2.5. Furnaces

2.6. Heat pumps

2.7. Boilers

2.8. Chillers

2.9. Cooling towers

2.10. Electric resistance coils

2.11. Condensing units

2.12. Motors for fans and pumps

2.13. Energy recovery devices

For each piece of equipment identified above include the following as applicable:

2.14. Equipment name or tag consistent with that found on the design documents.

2.15. Efficiency level.

2.16. Capacity.

2.17. Input power for fans and pumps.

3. Floor plan of the building identifying how portions of the buildings are assigned to the simulated

blocks and areas of the building that are not covered under the requirements of Section C403.1.1.

D600 Calculation procedure. Except as specified by this appendix, the standard reference design and

proposed design shall be configured and analyzed using identical methods and techniques.

D601 Simulation of the proposed building design. The proposed design shall be configured and

analyzed as specified in this section.

D601.1 Utility rates. For the purpose of calculating the HVAC TSPR the following simple utility rate

determined by the Washington State Department of Commerce shall be used:

$0.112/kWh of electricity

$1.158/therm of fossil fuel

2018 Washington State Energy Code CE-53

D601.2 Block geometry. The geometry of buildings shall be configured using one or more blocks.

Each block shall define attributes including block dimensions, number of floors, floor to floor height and

floor to ceiling height. Simulation software may allow the use of simplified shapes (such as rectangle, L

shape, H Shape, U shape or T shape) to represent blocks. Where actual building shape does not match

these pre-defined shapes, simplifications are permitted providing the following requirements are met:

1. The conditioned floor area and volume of each block shall match the proposed design within 10

percent.

2. The area of each exterior envelope component from Table C402.1.4 is accounted for within 10

percent of the actual design.

3. The area of vertical fenestration and skylights is accounted for within 10 percent of the actual

design.

4. The orientation of each component in 2 and 3 above is accounted for within 45 degrees of the

actual design.

The creation of additional blocks may be necessary to meet these requirements.

Exception: Portions of the building that are unconditioned or served by systems not covered by the

requirements of Section C403.1.1 shall be omitted.

D601.2.1 Number of blocks. One or more blocks may be required per building based on the following

restrictions:

1. Each block can have only one occupancy type (office, library, education, or retail). Therefore, at

least one single block shall be created for each unique use type.

2. Each block can be served by only one type of HVAC system. Therefore, a single block shall be

created for each unique HVAC system and use type combination. Multiple HVAC units of the

same type may be represented in one block. Table D601.10.2 provides directions for combining

multiple HVAC units or components of the same type into a single block.

3. Each block can have a single definition of floor to floor or floor to ceiling heights. Where floor

heights differ by more than two feet, unique blocks should be created for the floors with varying

heights.

4. Each block can include either above grade or below grade floors. For buildings with both above

grade and below grade floors, separate blocks should be created for each. For buildings with

floors partially above grade and partially below grade, if the total wall area of the floor(s) in

consideration is greater than or equal to 50 percent above grade, then it should be simulated as

a completely above grade block, otherwise it should be simulated as a below grade block.

5. Each wall on a façade of a block shall have similar vertical fenestration. The product of the

proposed design U-factor times the area of windows (UA) on each façade of a given floor

cannot differ by more than 15 percent of the average UA for that façade in each block. The

product of the proposed design SHGC times the area of windows (USHGC) on each façade of

a given floor cannot differ by more than 15 percent of the average USHGC for that façade in

each block. If either of these conditions are not met, additional blocks shall be created

consisting of floors with similar fenestration.

6. For a building model with multiple blocks, the blocks should be configured together to have the

same adjacencies as the actual building design.

D601.3 Thermal zoning. Each floor in a block shall be modeled as a single thermal zone or as five

thermal zones consisting of four perimeter zones and a core zone. Below grade floors shall be modeled

as a single thermal block. If any façade in the block is less than 45 feet in length, there shall only be a

single thermal zone per floor. Otherwise each floor shall be modeled with five thermal zones. A

perimeter zone shall be created extending from each façade to a depth of 15 feet. Where facades

intersect, the zone boundary shall be formed by a 45 degree angle with the two facades. The remaining

area or each floor shall be modeled as a core zone with no exterior walls.

CE-54 2018 Washington State Energy Code

D601.4 Occupancy.

D601.4.1 Occupancy type. The occupancy type for each block shall be consistent with the building

area type as determined in accordance with C405.4.2.1. Portions of the building that are building area

types other than office, school (education), library, or retail shall not be not be included in the

simulation.

D601.4.2 Occupancy schedule, density, and heat gain. The occupant density, heat gain, and

schedule shall be for office, retail, library, or school as specified by ASHRAE Standard 90.1

Normative Appendix C.

D601.5 Envelope components.

D601.5.1 Roofs. Roofs will be modeled with insulation above a steel roof deck. The roof U-factor and

area shall be modeled as in the proposed design. If different roof thermal properties are present in a

single block, an area weighted U-factor shall be used. Roof solar absorbtance shall be modeled at

0.70 and emittance at 0.90.

D601.5.2 Above grade walls. Walls will be modeled as steel frame construction. The U-factor and

area of above grade walls shall be modeled as in the proposed design. If different wall constructions

exist on the façade of a block an area-weighted U-factor shall be used.

D601.5.3 Below grade walls. The C-factor and area of below grade walls shall be modeled as in the

proposed design. If different slab on grade floor constructions exist in a block, an area-weighted C-

factor shall be used.

D601.5.4 Above grade exterior floors. Exterior floors shall be modeled as steel frame. The U-factor

and area of floors shall be modeled as in the proposed design. If different wall constructions exist in

the block an area-weighted U-factor shall be used.

D601.5.5 Slab on grade floors. The F-factor and area of slab on grade floors shall be modeled as in

the proposed design. If different below grade wall constructions exist in a block, an area-weighted F-

factor shall be used.

D601.5.6 Vertical fenestration. The window area and area weighted U-factor and SHGC shall be

modeled for each façade based the proposed design. Each exterior surface in a block must comply

with Section D601.2.1 item 5. Windows will be combined in to a single window centered on each

façade based on the area and sill height input by the user.

D601.5.7 Skylights. The skylight area and area weighted U-factor and SHGC shall be modeled for

each floor based the proposed design. Skylights will be combined in to a single skylight centered on

the roof of each zone based on the area and sill height input by the user.

D601.6 Lighting. Interior lighting power density shall be equal to the allowance in Table C405.4.2(1) for

office, retail, library, or school. The lighting schedule shall be for office, retail, library, or school as

specified by ASHRAE Standard 90.1 Normative Appendix C. The impact of lighting controls is assumed

to be captured by the lighting schedule and no explicit controls shall be modeled. Exterior lighting shall

not be modeled.

D601.7 Miscellaneous equipment. The miscellaneous equipment schedule and power shall be for

office, retail, library, or school as specified by ASHRAE Standard 90.1 Normative Appendix C. The

impact of miscellaneous equipment controls is assumed to be captured by the equipment schedule and

no explicit controls shall be modeled.

D601.8 Elevators. Elevators shall not be modeled.

601.9 Service water heating equipment. Service water heating shall not be modeled.

D601.10 On-site renewable energy systems. On-site Renewable Energy Systems shall not be

modeled.

D601.11 HVAC equipment. HVAC systems shall meet the requirements of Section C403 Mechanical

Systems.

2018 Washington State Energy Code CE-55

D601.11.1 Supported HVAC systems. At a minimum, the HVAC systems shown in Table D601.11.1

shall be supported by the simulation program.

TableD601.11.1

PROPOSED BUILDING HVAC SYSTEMS SUPPORTED BY

HVAC TSPR SIMULATION SOFTWARE

System No.

System Name

System Abbreviation

Packaged Terminal Air Conditioner

PTAC

Packaged Terminal Air Heat Pump

PTHP

Packaged Single Zone Gas Furnace

PSZGF

Packaged Single Zone Heat Pump (air to air only)

PSZHP

Variable Refrigerant Flow (air cooled only)

VRF

Four Pipe Fan Coil

FPFC

Water Source Heat Pump

WSHP

Ground Source Heat Pump

GSHP

Packaged Variable Air Volume (DX cooling)

PVAV

Variable Air Volume (hydronic cooling)

VAV

Variable Air Volume with Fan Powered Terminal Units

VAVFPTU

Dedicated Outdoor Air System (in conjunction with systems 1-8)

DOAS

D601.11.2 Proposed building HVAC system simulation. The HVAC systems shall be modeled as

in the proposed design with clarifications and simplifications as described in Table D601.11.2. System

parameters not described in the following sections shall be simulated to meet the minimum

requirements of Section C403. All zones within a block shall be served by the same HVAC system

type as described in Section D601.2.1 item 2. Where multiple system components serve a block,

average values weighed by the appropriate metric as described in this section shall be used. Heat

loss from ducts and pipes shall not be modeled.

Exception: Where the building permit applies to only a portion of an HVAC system and remaining

components will be designed under a future building permit, the future components shall be

modeled to meet, but not exceed, the requirements of Section C403.

TABLE D601.11.2

PROPOSED BUILDING SYSTEM PARAMETERS

Category

Parameter

Fixed or User

Defined

Required

Applicable

Systems

HVAC System

Type

System Type

User Defined

Selected from Table D601.11.1

All

System Sizing

Design Day

Information

Fixed

99.6% heating design and 1% dry-bulb

and 1% wet-bulb cooling design

All

Zone Coil

Capacity

Fixed

Sizing factors used are 1.25 for heating

equipment and 1.15 for cooling equipment

All

Supply Airflow

Fixed

Based on a supply-air-to-room-air

temperature set-point difference of 20°F

1-11

Fixed

Equal to required outdoor air ventilation

Outdoor

Ventilation Air

Outdoor

Ventilation Air

Flow Rate

Fixed

As specified in ASHRAE Standard 90.1

Normative Appendix C, adjusted for

proposed DCV control

All

CE-56 2018 Washington State Energy Code

TABLE D601.11.2 (continued)

PROPOSED BUILDING SYSTEM PARAMETERS

Category

Parameter

Fixed or User

Defined

Required

Applicable

Systems

System

Operation

Space

temperature Set

points

Fixed

As specified in ASHRAE Standard 90.1

Normative Appendix C

1-11

Fan Operation –

Occupied

User Defined

Runs continuously during occupied hours

or cycled to meet load

1-11

Fan Operation –

Occupied

Fixed

Fan runs continuously during occupied

hours

Fan Operation -

Night Cycle

Fixed

Fan cycles on to meet setback

temperatures

1-11

Packaged

Equipment

Efficiency

DX Cooling

Efficiency

User Defined

Cooling COP without fan energy

calculated in accordance with ASHRAE

Standard 90.1 Section 11.5.2c.

1, 2, 3, 4, 5,

7, 8, 9, 11,

Heat Pump

Efficiency

User Defined

Heating COP without fan energy

calculated in accordance with ASHRAE

Standard 90.1 Section 11.5.2c.

2, 4, 5, 7, 8

Furnace

Efficiency

User Defined

Furnace thermal efficiency

3, 11

Heat Pump

Supplemental

Heat

Control

Fixed

Supplemental electric heat locked out

above 40°F. Runs In conjunction with

compressor between 40°F and 0°F.

2, 4

System Fan

Power

Design Fan

Power (W/cfm)

User Defined

Input electric power for all fans in required

to operate at fan system design conditions

divided by the supply airflow rate

All

Single Zone

System Fan

Power During

Dead band

(W/cfm)

User Defined

W/cfm during dead band for VAV or

multispeed single zone fans

3, 4, 5, 6, 7,

Variable Air

Volume

Systems

Part Load Fan

Controls

User Defined

VFD included. User specifies presence of

static pressure reset.

9, 10, 11

Supply Air

Temperature

Controls

User defined

If not SAT reset constant at 55°F. SAT

reset results in 60°F SAT during low load

conditions

9, 10, 11

Minimum

Terminal Unit

airflow

percentage

User Defined

Average minimum terminal unit airflow

percentage for block weighted by cfm

9, 10, 11

Terminal Unit

Heating Source

User Defined

Electric or hydronic

9, 10, 11

Fan Powered

Terminal Unit

(FPTU) Type

User Defined

Series or parallel FPTU

Parallel FPTU

Fan

Fixed

Sized for 50% peak primary air at 0.35

W/cfm

Series FPTU Fan

Fixed

Sized for 50% peak primary air at 0.35

W/cfm

Economizer

Presence

User Defined

Yes or No

3, 4, 9, 10,

Economizer High

Limit

Fixed

75°F fixed dry-bulb

3, 4, 9, 10,

2018 Washington State Energy Code CE-57

TABLE D601.11.2 (continued)

PROPOSED BUILDING SYSTEM PARAMETERS

Category

Parameter

Fixed or User

Defined

Required

Applicable

Systems

Energy

Recovery

Sensible

Effectiveness

User Defined

Heat exchanger sensible effectiveness at

design heating and cooling conditions

3, 4, 9, 10,

11, 12

Latent

Effectiveness

User Defined

Heat exchanger latent effectiveness at

design heating and cooling conditions

3, 4, 9, 10,

11, 12

Economizer

Bypass

User Defined

If ERV is bypassed during economizer

conditions

3, 4, 9, 10,

11, 12

Energy Recovery

Temp Control

User Defined

If bypass, target supply air temperature

3, 4, 9, 10,

11, 12

Fan Power

Reduction during

Bypass (W/cfm)

User Defined

If ERV system include bypass, static

pressure set point and variable speed fan,

fan power can be reduced during

economizer conditions

3, 4, 9, 10,

11, 12

Demand

Controlled

Ventilation

DCV Application

User Defined

Percent of block floor area under DCV

control

3, 4, 9, 10,

11, 12

DOAS

DOAS Fan Power

W/cfm

User Defined

Fan input power in W/cfm of supply

airflow

DOAS

Supplemental

Heating and

Cooling

User Defined

Heating source, cooling source

DOAS Supply Air

Temperature

Control

User Defined

SAT set point if DOAS includes

supplemental heating or cooling and

active temperature controls

Heating Plant

Boiler Efficiency

User Defined

Boiler thermal efficiency

1, 6, 7, 9,

10, 11, 12

Heating Water

Pump Power

(W/gpm)

User Defined

Pump input W/gpm heating water flow

1, 6, 7, 9,

10, 11, 12

Heating Water

Loop

Temperature

Fixed

180°F supply, 130°F return

1, 6, 9,

10,11

Chilled Water

Plant

Chiller

Compressor Type

User Defined

Screw/Scroll, Centrifugal or Reciprocating

6,1 0, 11,

Chiller Condenser

Type

User Defined

Air cooled or water cooled

6, 10, 11,

Chiller Full Load

Efficiency

User Defined

Chiller COP

6, 10, 11,

Chilled Water

loop

Configuration

User Defined

Variable flow primary only, constant flow

primary – variable flow secondary

6, 10, 11,

Chilled Water

Pump Power

(W/gpm)

User Defined

Pump input W/gpm chilled water flow

6, 10, 11,

Chilled Water

Temperature

Reset Included

User Defined

Yes/No

6, 10, 11,

CE-58 2018 Washington State Energy Code

TABLE D601.11.2 (continued)

PROPOSED BUILDING SYSTEM PARAMETERS

Category

Parameter

Fixed or User

Defined

Required

Applicable

Systems

Chilled Water

Plant (cont.)

Chilled Water

Temperature

Reset Schedule

(if included)

Fixed

Outdoor air reset: CHW supply

temperature of 44°F at 80°F outdoor air

dry bulb and above, CHW supply

temperature of 54°F at 60°F outdoor air

dry bulb temperature and below, ramped

linearly between

6, 10, 11,

Condenser Water

Pump Power

(W/gpm)

User Defined

Pump input W/gpm condenser water flow

6, 7, 8, 9,

10, 11, 12

Condenser Water

Pump Control

User Defined

Constant speed or variable speed

6, 7, 10, 11,

Cooling Tower

Efficiency

User Defined

gpm/hp tower fan

6, 10, 11,

Cooling Tower

Fan Control

User Defined

Constant or variable speed

6, 10, 11,

Cooling Tower

Approach and

Range

User Defined

Design cooling tower approach and range

temperature

6, 10, 11,

Heat Pump

Loop Flow

Control

Loop flow and

Heat Pump

Control Valve

Fixed

Two position Valve with VFD on Pump.

Loop flow at 3 gpm/ton

7, 8

Heat Pump

Loop

Temperature

Control

Fixed

Set to maintain temperature between

50°F and 70°F

GLHP Well

Field

Fixed

Bore depth = 250’

Bore length 200’/ton for greater of cooling

or heating load

Bore spacing = 15’

Bore diameter = 5”

¾” Polyethylene pipe

Ground and grout conductivity =

4.8 Btu-in/h-ft

a. Where multiple fan systems serve a single block, fan power is based on weighted average using on

supply air cfm.

b. Where multiple cooling systems serve a single block, COP is based on a weighted average using cooling

capacity.

c. Where multiple heating systems serve a single block, thermal efficiency or heating COP is based on a

weighted average using heating capacity.

d. Where multiple boilers or chillers serve a heating water or chilled water loop, efficiency is based on a

weighted average for using heating or cooling capacity.

D602 Simulation of the standard reference design. The standard reference design shall be configured

and analyzed as specified in this section.

D602.1 Utility rates. Same as proposed.

D602.2 Blocks. Same as proposed.

D602.3 Thermal zoning. Same as proposed.

D602.4 Occupancy type, schedule, density, and heat gain. Same as proposed.

2018 Washington State Energy Code CE-59

D602.5 Envelope components. Same as proposed.

D602.6 Lighting. Same as proposed.

D602.7 Miscellaneous equipment. Same as proposed.

D602.8 Elevators. Not modeled. Same as proposed.

D602.9 Service water heating equipment. Not modeled. Same as proposed.

D602.10 On-site renewable energy systems. Not modeled. Same as proposed.

D602.11 HVAC equipment. The standard reference design HVAC equipment consists of separate

space conditioning systems and dedicated outside air systems as described in Table D602.11 for the

appropriate building occupancies.

TABLE D602.11

STANDARD REFERENCE DESIGN HVAC SYSTEMS

Parameter

Building Type

Large Office

Small Office and

Libraries

Retail

School

System Type

Water-source Heat

Pump

Packaged air-

source Heat Pump

Packaged air-

source Heat Pump

Packaged air-

source Heat Pump

Fan control

Cycle on load

Space condition fan power (W/cfm)

0.528

0.522

0.528

Heating/Cooling sizing factor

1.25/1.15

Supplemental heating availability

<40°F

Modeled cooling COP (Net of fan)

4.46

3.83

4.25

3.83

Modeled heating COP (Net of fan)

4.61

3.81

3.57

3.81

Cooling Source

DX (heat pump)

Heat source

Heat Pump

OSA Economizer

Yes

Occupied ventilation source

DOAS

DOAS Fan Power

(W/cfm of outside air)

0.819

0.730

0.742

DOAS temperature control

g, h

Bypass

Wild

Bypass

ERV efficiency (sensible only)

70%

WSHP Loop Heat Rejection

Cooling Tower

WSHP Loop Heat Source

Gas Boiler

WSHP Loop Temperature Control

50°F to 70°F

WSHP circulation Pump W/gpm

WSHP Loop Pumping Control

HP Valves & pump

VSD

CE-60 2018 Washington State Energy Code

a. Offices <50,000 ft

use “Small Office” parameters; otherwise use “Large Office” parameters.

b. Space conditioning system shall cycle on to meet heating and cooling set point schedules as specified in

ASHRAE Standard 90.1 Normative Appendix C. One space conditioning system is modeled in each zone.

Conditioning system fan operation is not necessary for ventilation delivery.

c. The equipment capacities (i.e. system coil capacities) for the standard reference design building design shall

be based on design day sizing runs and shall be oversized by 15% for cooling and 25% for heating.

d. COPs shown are direct heating or cooling performance and do not include fan energy use. See 90.1

appendix G (G3.1.2.1) for separation of fan from COP in packaged equipment for units where the efficiency

rating includes fan energy (e.g., SEER, EER, HSPF, COP).

e. Economizer on space conditioning systems shall be simulated when outdoor air conditions allow free

cooling. Economizer high limit shall be based on differential dry-bulb control. DOAS system continues to

operate during economizer mode.

f. Airflow equal to the outside air ventilation requirements is supplied and exhausted through a separate DOAS

system including a supply fan, exhaust fan, and sensible only heat exchanger. No additional heating or

cooling shall be provided by the DOAS. A single DOAS system will be provided for each block. The DOAS

supply and return fans shall run whenever the HVAC system is scheduled to operate in accordance with

ASHRAE Standard 90.1 Normative Appendix C.

g. “Wild” DOAS control indicates no active control of the supply air temperature leaving the DOAS system.

Temperature will fluctuate based only on entering and leaving conditions and the effectiveness of ERV.

h. “Bypass” DOAS control includes modulating dampers to bypass ERV with the intent to maintain supply air

temperature at a maximum of 60°F when outside air is below 75°F. Once outside air is above 75°F bypass

dampers will be fully closed.

i. Includes a single axial fan cooling tower with variable-speed fans at 40.2 gpm/hp, sized for an approach of

10°F and a range of 10°F.

j. Includes a single natural draft boiler with 80% E

k. Loop boiler and heat rejection shall be controlled to maintain loop temperature entering heat pumps between

50°F and 70°F.

l. Pump motor input power shall be 16 W/gpm.

m. Loop flow shall be variable with variable speed drive pump and unit fluid flow shutoff at each heat pump

when its compressor cycles off.

2018 Washington State Energy Code CE-61

APPENDIX E

RENEWABLE ENERGY

The provisions contained in this appendix are not mandatory unless

specifically referenced in the adopting ordinance.

E101.1 On-site renewable energy systems. Each new commercial building or addition larger than 5,000

square feet of gross conditioned floor area shall include a renewable energy generation system consisting

of at least 70 watts rated peak photovoltaic energy production, or 240 kBtu of annual solar water heating

energy production, per 1,000 square feet of conditioned floor area or fraction thereof. For buildings over 5

stories in height, the conditioned area for this calculation shall be based on the conditioned area of the

largest 5 above-grade stories in the building. If the on-site renewable energy option in C406 is selected,

this energy shall be in addition to that required by C406.

Exception: Alternate means of achieving equivalent energy savings are permissible where approved

by the code official, if the calculated net annual energy savings equals or exceeds the calculated

annual energy production of the required on-site renewable energy system.

CE-62 2018 Washington State Energy Code

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2018 Washington State Energy Code CE-63

APPENDIX F

OUTCOME-BASED ENERGY BUDGET

The provisions contained in this appendix are not mandatory unless

specifically referenced in the adopting ordinance.

F101.1 General. This section is an outcome-based energy budget compliance requirement pursuant to

RCW Chapter 19.27A.160 to incrementally move toward achieving by 2031 a 70 percent reduction in

annual net energy use compared with 2006 baseline. As an outcome-based energy budget, this

requirement uses a building’s actual energy use to determine compliance.

F101.2 Scope. Buildings permitted under this section shall document one year of net energy use below

an energy budget within three years after occupancy and every five years thereafter. Buildings and sites

shall also be designed with the ability to offset in the future all estimated energy needs through

renewable energy generation with minimum 40 percent on-site, maximum 40 percent off-site, and

maximum 20 percent through green power purchase. Buildings that exceed the energy budget by up to

20 percent shall offset the excess amount through a green power purchase agreement. Buildings that

exceed the energy budget by more than 20 percent shall, using a posted performance bond or financial

security, offset the excess amount over 20 percent by installing renewable energy or with an energy

retrofit.

F101.3 Building permit submittal. Building designs shall establish on the Washington State Outcome-

Based Energy Budget Form (Figure F101.3):

1. The anticipated building energy use is lower than the energy budget.

2. The energy generation ability in the future is greater than or equal to the anticipated

building energy use.

F101.3.1 Anticipated building energy use. The total yearly energy use from all metered fuel sources

is the anticipated building energy use. Any energy used from district energy, combined heat and

power, renewable energy, or captured waste heat systems must be metered. Buildings with any non-

metered energy sources are not permitted for compliance with this section. All secondary spaces and

services (examples: exterior building and site lighting, surface parking, garages, and exterior

swimming pools) associated with the building shall be included in the overall energy use total. The

anticipated site Energy Use Intensity (EUI) for each fuel source shall be reported in units of kWh/ft

/yr

or kBtu/ ft

/yr using the conversions listed below:

Metered Fuel Source

to kWh:

to kBTU

Electric

kWh x 1

kWh x 3.412

Gas

Therm x 29.308

Therm x 100

Propane

Cubic Foot x 0.738

Cubic Foot x 2.5185

Fuel Oil

Gallon x 43.872

Gallon x 149.6905

F101.3.2 Building use and occupancy types. Building use and occupancy types permitted are

indicated in Table F101.3.2.

F101.3.3 Maximum site energy budget. Table F101.3.2 indicates the site EUI budget for each

building use and occupancy type along with the building enclosure requirements for all use and

occupancy types.

F101.3.3.1 Mixed-use buildings. For buildings that contain more than one building use or

occupancy type, the overall energy budget shall be based on the individual floor area percentage

totals of each use times the individual energy budget and summing the results of all individual areas.

CE-64 2018 Washington State Energy Code

F101.3.3.2 Energy budget level options. Development teams may commit to a future, more

stringent energy budget level from Table F101.3.2. Actual energy use and energy generation ability

will be evaluated on this lower budget level.

F101.3.3.3 Energy modeling. A proposed building energy model is required for compliance with

Section F101.3.2. A baseline energy model is not required. The proposed design model must show

estimated energy use below the energy.

F101.3.4 Energy generation ability. Permit documents shall indicate the location, space allocated,

and connection pathways for future installation of all potential energy generation systems. Only items

defined by the Washington State Energy Code as On-Site Renewable Energy shall be used to meet

energy generation requirements.

F101.3.4.1 Energy Generation Categories. The development team shall complete the

Washington State Outcome-Based Energy Budget Form (Figure F101.3) to show the total

renewable energy generation ability in the following categories:

Building Integral: Renewable energy generation sources attached to the building.

This value, combined with the on-site value, shall be at least 40 percent of the

energy budget.

On-site: Renewable energy generation sources located on the building site property.

This value, combined with the building integral value, shall be at least 40 percent of

the energy budget.

Off-site: Renewable energy generation sources not located on the building site. This

amount is limited to 40 percent of the energy budget. A specific off-site location does

not need to be identified.

Green Power: Renewable energy purchased through the electric utility provider for the

building. This amount is limited to 20 percent of the energy budget.

F101.3.4.2 Energy generation ability for building sites within a 2030 district. The

development team for building sites within a designated 2030 District recognized by

Architecture 2030 may use the Architecture 2030 Challenge 70 percent energy reduction

target from the 2003 baseline as the energy budget. Building locations meeting this criteria

and choosing this energy budget are exempt from the building integral and on-site

requirements in Section F101.3.4.1. Green power remains capped at 20 percent. The

generation requirements may be split, in any amount, among the building integral, on-site,

or off- site categories. Actual energy use will be evaluated against the Architecture 2030

Challenge 70 percent energy reduction budget.

F101.4 Actual energy use submittal. The building owner or representative shall submit energy

use documentation summary from all energy source providers or from an energy benchmarking

service to the building code official. Code compliance is achieved with net energy use below the

energy budget for any continuous 12-month span within the first three years of occupancy.

F101.4.1 Energy use monitoring period and occupancy. The energy use monitoring

timeframe shall start on the first full-month billing cycle of the utility or energy source

provider(s) six months after a certificate of occupancy is issued. Buildings shall be deemed

substantially occupied when a minimum 85 percent of the floor area, including all common

areas, is occupied. The energy monitoring start time may be delayed up to an additional 6

months from certificate of occupancy (up to 12 months total) if 85 percent occupancy is not yet

achieved. Buildings not 85 percent occupied after 12 months shall start the monitoring period

for the portions occupied with an energy budget based on the spaces occupied and all

common areas combined.

F101.4.2 Change of occupancy use during monitoring period. If an area within the

building changes from one occupancy use to another with a different target EUI energy

budget or if the building occupancy level drops below 50 percent, the target EUI energy

budget shall be recalculated to become the new energy budget against which the building

energy use shall be compared for compliance.

2018 Washington State Energy Code CE-65

F101.4.3 Energy metering. All building spaces and uses subject to an energy budget or a

portion of the energy budget shall be metered separately for all energy uses.

F101.4.4 Energy budget responsibility. The building owner is responsible for the compliance

of the whole building. At the building owner’s discretion, responsibility for the energy use

budget may be divided and transferred into portions attributable to the occupant, operator or

controller of each energy budget space. Common area spaces not under the control of an

occupant or tenant may not be transferred.

F101.5 Actual energy use above the energy budget. Buildings exceeding the energy budget

are not in compliance with the energy code and the building owner shall complete one of the

following measures within one year:

1. Owners of buildings with actual energy use that exceeds the energy budget by up to 20

percent may offset the excess energy amount through annual green power purchase

agreement from the utility provider at a rate of 1.1 times the excess energy amount until

future code compliance is demonstrated.

2. Owners of buildings with actual energy use that exceeds the energy budget by more than

20 percent and up to 40 percent shall complete item 1 and either install on-building, on-

site, or off-site energy generation equipment or invest in an energy conservation retrofit

using the performance bond or financial security for energy amount remaining above 20

percent.

3. Owners of buildings with actual energy use that exceeds the energy budget by more than

40 percent shall complete item 1, item 2, and post a replacement performance bond or

financial security equal to the first bond or security amount.

F101.5.1 Continued energy monitoring. Upon completing the necessary compliance

measure(s) in Section F101.5 the building owner is provided another three-year timeframe to

achieve and document net energy use below the energy budget for any continuous 12-month

span. Owners of buildings that remain more than 20 percent above the energy budget shall

repeat the measures in Section F101.5, up to three times maximum, using the performance

bond or financial security to install energy generation equipment or to install an energy retrofit

and post a new performance bond equal to the first.

F101.5.2 Tradable certificate for energy savings. As an alternate to the requirements of

Section F101.5 a building owner may, when this market-based instrument becomes available,

purchase a Tradable Certificate for Energy Savings (TCES) or ‘white certificates’ from a

building or entity with energy savings. The building owner shall purchase TCES’s equal to 1.1

times the amount that the building’s actual energy use exceeds the energy budget.

F101.6 Performance bond or financial security. A building developer must secure and submit

to the code official a performance bond or an irrevocable financial security letter of credit from a

State of Washington financial institution prior to certificate of occupancy issuance. The bond or

security shall have a value equal to $4.00 per square foot of gross conditioned floor area. The

bond or security shall be used only to install renewable energy on the building or for investment

into energy conservation measures as part of an energy retrofit. The bond or security may also be

held for one additional three-year energy-monitoring period if green power is purchased. Upon

demonstrated compliance with the energy budget, the bond or security requirement shall be

released.

F101.6.1 Failure to submit energy use data. Building owners that fail to submit energy use

data at the end of the three-year monitoring period shall forfeit the full amount of the

performance bond or financial security as payment to the local jurisdiction. Building owners that

fail to submit energy use data at the end of each continuing five year monitoring period shall be

fined an amount equal to the original bond or financial security by the local jurisdiction.

F101.7 Continued energy budget certification. After achieving code compliance buildings

shall be required every five years to document a continuous 12-month span with net energy

use that is lower than the required energy budget. Owners of buildings with actual energy use

CE-66 2018 Washington State Energy Code

that is at least 2.5 percent below their energy budget (from year permitted baseline, not

voluntary year) may sell, when a future market-based instrument becomes available, their

unused energy equivalents in the form of a ‘white certificate’ or Tradable Certificate for Energy

Savings.

F101.8 Local amendments. Local jurisdictions may amend the current code cycle EUI maximum

energy budget by adopting a more-stringent future code year value stated in Table F101.3.2.

TABLE F101.3.2

WASHINGTON STATE OUTCOME-BASED ENERGY BUDGET

Zone 4C:

Site EUI

Base

Current

Future

Building Occupancy/ Use

/year

2003

2018

2021

2024

2027

2030

A-3

Library

kWh

30.5

14.6

13.3

11.9

10.5

9.1

kBtu

104

49.9

45.3

40.6

35.9

31.2

Office/Bank

kWh

19.7

8.5

7.8

7.2

6.6

5.9

kBtu

67.3

28.9

26.7

24.5

22.4

20.2

Medical Office (non-

diagnostic)

kWh

14.8

7.1

6.4

5.8

5.1

4.4

kBtu

50.4

24.2

21.9

19.6

17.4

15.1

School K-12

kWh

17.1

8.2

7.4

6.7

5.9

5.1

kBtu

58.4

28.0

25.4

22.8

20.2

17.5

1-2

Hospital (in-patient)

kWh

51.6

24.8

22.5

20.1

17.8

15.5

kBtu

176.1

84.5

76.6

68.7

60.8

52.8

Grocery / Food Market

kWh

66.6

32.0

29.0

26.0

23.0

20.0

kBtu

227.4

109.1

98.9

88.7

78.5

68.2

Retail

kWh

25.7

12.3

11.2

10.0

8.9

7.7

kBtu

87.5

42.0

38.1

34.1

30.2

26.3

S-1

Parking

Enclosed garage

kWh

3.8

2.3

2.0

1.7

1.4

1.1

kBtu

13.0

8.0

7.0

5.9

4.9

3.9

Open garage

kWh

2.3

1.4

1.2

1.0

0.9

0.7

kBtu

7.8

4.8

4.2

3.6

3.0

2.3

S-2

Non-Refrigerated

Distribution/Shipping

kWh

8.6

4.1

3.7

3.3

3.0

2.6

kBtu

29.2

14.0

12.7

11.4

10.1

8.8

2018 Washington State Energy Code CE-67

TABLE F101.3.2 (continued)

WASHINGTON STATE OUTCOME-BASED ENERGY BUDGET

Zone 4C:

Site EUI

Base

Current

Future

Building Occupancy/ Use

/year

2003

2018

2021

2024

2027

2030

R-2 Multi-Family (3+ stories)

Lobby/Common Area

kWh

29.0

17.5

15.3

13.1

10.9

8.7

kBtu

59.7

52.2

44.7

37.2

29.7

Studio/Micro-Unit

kWh

9238

3284

3156

3028

2900

2771

kBtu

31520

11205

10768

10331

9893

9456

One Bedroom

kWh

18476

6568

6312

6055

5799

5543

kBtu

63040

22411

21536

20661

19787

18912

Two Bedroom

kWh

27714

9852

9468

9083

8699

8314

kBtu

94560

33616

32304

30992

29680

28368

Three Bedroom

kWh

36952

13136

12624

12111

11598

11086

kBtu

126080

44821

43072

41323

39573

37824

Additional Bedroom

kWh

9238

3284

3156

3028

2900

2771

kBtu

31520

11205

10768

10331

9893

9456

All Occupancies/Use Types

2003

2018

2021

2024

2027

2030

U-Factor

Vertical Fenestration

Non-metal

0.28

0.27

0.25

0.24

0.23

Metal - Fixed

0.33

0.31

0.28

0.26

0.23

Metal - Operable

0.34

0.32

0.29

0.26

0.23

Roof

0.016

0.015

0.014

0.013

0.012

Wall (above/below grade)

0.031

0.028

0.024

0.021

0.018

Floors

0.024

0.023

0.021

0.020

0.018

F-value

Slab on Grade

0.41

0.39

0.36

0.34

0.32

CFM75/ft

Air Leakage

0.25

0.17

0.14

0.11

0.08

CE-68 2018 Washington State Energy Code

TABLE F101.3.2 (continued)

WASHINGTON STATE OUTCOME-BASED ENERGY BUDGET

Zone 5B:

Site EUI

Base

Current

Future

Building Occupancy/ Use

/year

2003

2018

2021

2024

2027

2030

A-3

Library

kWh

31.9

15.3

13.9

12.4

11.0

9.6

kBtu

108.8

52.2

47.3

42.4

37.5

32.6

Office/Bank

kWh

20.1

9.1

8.3

7.5

6.8

6.0

kBtu

68.6

30.9

28.3

25.8

23.2

20.6

Medical Office (non-

diagnostic)

kWh

15.0

7.2

6.5

5.9

5.2

4.5

kBtu

51.3

24.6

22.3

20.0

17.7

15.4

School K-12

kWh

18.3

8.8

8.0

7.1

6.3

5.5

kBtu

62.4

30.0

27.2

24.3

21.5

18.7

1-2

Hospital (in-patient)

kWh

48.5

23.3

21.1

18.9

16.7

14.6

kBtu

165.5

79.4

72.0

64.5

57.1

49.7

Grocery / Food Market

kWh

66.3

31.8

28.8

25.8

22.9

19.9

kBtu

226.1

108.5

98.4

88.2

78.0

67.8

Retail

kWh

28.4

13.6

12.4

11.1

9.8

8.5

kBtu

97.0

46.6

42.2

37.8

33.5

29.1

S-1

Parking

Enclosed garage

kWh

3.8

2.3

2.0

1.7

1.4

1.1

kBtu

13.0

8.0

7.0

5.9

4.9

3.9

Open garage

kWh

2.3

1.4

1.2

1.0

0.9

0.7

kBtu

7.8

4.8

4.2

3.6

3.0

2.3

S-2

Non-Refrigerated

Distribution/Shipping

kWh

10.5

5.0

4.6

4.1

3.6

3.1

kBtu

35.8

17.2

15.6

14.0

12.4

10.7

R-2 Multi-Family (3+ stories)

Lobby/Common Area

kWh

29.0

18.8

16.3

13.8

11.2

8.7

kBtu

64.2

55.6

46.9

38.3

29.7

Studio/Micro-Unit

kWh

9238

3495

3314

3133

2952

2771

kBtu

31520

11925

11308

10691

10073

9456

One Bedroom

kWh

18476

6990

6628

6267

5905

5543

kBtu

63040

23851

22616

21381

20147

18912

Two Bedroom

kWh

27714

10485

9943

9400

8857

8314

kBtu

94560

35776

33924

32072

30220

28368

Three Bedroom

kWh

36952

13980

13257

12533

11809

11086

kBtu

126080

47701

45232

42763

40293

37824

Additional Bedroom

kWh

9238

3495

3314

3133

2952

2771

kBtu

31520

11925

11308

10691

10073

9456

2018 Washington State Energy Code CE-69

TABLE F101.3.2 (continued)

WASHINGTON STATE OUTCOME-BASED ENERGY BUDGET

Zone 5B:

All Occupancies/Use Types

2003

2018

2021

2024

2027

2030

U-Factor

Vertical Fenestration

Non-metal

0.25

0.23

0.21

0.18

0.16

Metal - Fixed

0.31

0.27

0.23

0.20

0.16

Metal - Operable

0.32

0.28

0.24

0.20

0.16

Roof

0.016

0.015

0.014

0.013

0.012

Wall (above/below grade)

0.031

0.028

0.024

0.021

0.018

Floors

0.024

0.023

0.021

0.020

0.018

F-value

Slab on Grade

0.41

0.39

0.36

0.34

0.32

CFM75/ft

Air Leakage

0.25

0.17

0.14

0.11

0.08

a. Lighting Power Allowance must still comply with Table C405.4.2(2).

b. Applicable to heated warehouses only.

CE-70 2018 Washington State Energy Code

FIGURE F101.3.2

WASHINGTON STATE OUTCOME-BASED ENERGY BUDGET FORM

(reserved for graphics)

Building occupancy/use

Conditioned floor area SF

Code maximum site EUI energy budget

Predicted EUI

Electric

Gas

Propane

Oil

Other (source/generation)

Generation Potential EUI

Building Integral

(combined must exceed 40%)

On-site

Offsite

(max 40%)

Purchase

(max 40%)

Percentage better than energy budget

Percentage potential EUI above predicted EUI

PROJECT SUMMARY

Building Name

Address

City

Owner

Address

City, State, Zip

PROJECT CERTIFICATION

Name

Firm

Date

(seal)

2018 Washington State Energy Code CE-71