WSR 22-01-025
EXPEDITED RULES
BUILDING CODE COUNCIL
[Filed December 3, 2021, 10:01 a.m.]
Title of Rule and Other Identifying Information: Corrections to chapter 51-52 WAC: Adoption and amendment of the 2018 International Mechanical Code.
Purpose of the Proposal and Its Anticipated Effects, Including Any Changes in Existing Rules: This filing is making corrections to the adopted amendments to the 2018 International Mechanical Code, as adopted by the state building code council on November 8, 2019.
Reasons Supporting Proposal: Several inconsistencies were found upon review of the code after initial adoption. The following editorial corrections are being made:
1. In Table 403.3.1.1, under private dwellings, singe [single] and multiple, laundry areas is removed as there is no longer a code requirement for local ventilation of laundry areas, so this just creates confusion. As the requirement was removed, the footnote associated was also removed.
2. Two subsections from Section 606 were inadvertently filed under Section 601. These two subsections were moved to the appropriate place in WAC 51-52-0606.
3. At the final hearing, there were changes made to add requirements for two additional referenced standards for refrigerant alternatives with a lower global warming potential. While these standards were added to the list of reference standards, the citation in code text was not included as intended. Section 101.2 adds a reference to UL 60335 part 2-40 and Section 1101.6 adds an exception for A2L refrigerants that comply with ASHRAE 15-2019.
4. In Section 1209.5, there was a change to the model code language that restructured this section. The retention of the previous language was not intended to overwrite the current model code requirement in the renumbered Section 1209.5.1. The state amendment was corrected to move the language from the amended version of 1209.5.1 to the base language in 1209.5 to clarify that the model code Section 1209.5.1 is still effective.
5. The referenced standard chapter was corrected to include corrected titles and effective editions for three standards referenced in the code, along with the location of those section references.
Statute Being Implemented: Chapter
19.27 RCW.
Rule is not necessitated by federal law, federal or state court decision.
Name of Proponent: Washington state building code council, governmental.
Name of Agency Personnel Responsible for Drafting and Implementation: Krista Braaksma, 1500 Jefferson Street S.E., Olympia, 360-407-9278; Enforcement: Local jurisdictions.
This notice meets the following criteria to use the expedited adoption process for these rules:
Corrects typographical errors, make address or name changes, or clarify language of a rule without changing its effect.
Explanation of the Reason the Agency Believes the Expedited Rule-Making Process is Appropriate:
NOTICE
THIS RULE IS BEING PROPOSED UNDER AN EXPEDITED RULE-MAKING PROCESS THAT WILL ELIMINATE THE NEED FOR THE AGENCY TO HOLD PUBLIC HEARINGS, PREPARE A SMALL BUSINESS ECONOMIC IMPACT STATEMENT, OR PROVIDE RESPONSES TO THE CRITERIA FOR A SIGNIFICANT LEGISLATIVE RULE. IF YOU OBJECT TO THIS USE OF THE EXPEDITED RULE-MAKING PROCESS, YOU MUST EXPRESS YOUR OBJECTIONS IN WRITING AND THEY MUST BE SENT TO Andrew Klein, Acting Chair, Washington State Building Code Council, P.O. Box 41449, Olympia, WA 98504-1449, phone 360-407-9255, email sbcc@des.wa.gov, AND RECEIVED BY February 22, 2022.
November 30, 2021
Andrew S. Klein
Council Acting Chair
OTS-3508.2
AMENDATORY SECTION(Amending WSR 21-05-020, filed 2/8/21, effective 3/11/21)
WAC 51-52-0403Section 403—Mechanical ventilation.
403.1 Ventilation system. Mechanical ventilation shall be provided by a method of supply air and return or exhaust air. The amount of supply air shall be approximately equal to the amount of return and exhaust air. The system shall not be prohibited from producing negative or positive pressure. The system to convey ventilation air shall be designed and installed in accordance with Chapter 6.
403.2 Outdoor air required. The minimum outdoor airflow rate shall be determined in accordance with Section 403.3.
EXCEPTIONS: | 1. Where the registered design professional demonstrates that an engineered ventilation system design will prevent the maximum concentration of contaminants from exceeding that obtainable by the rate of outdoor air ventilation determined in accordance with Section 403.3, the minimum required rate of outdoor air shall be reduced in accordance with such engineered system design. |
| 2. Alternate systems designed in accordance with ASHRAE Standard 62.1 Section 6.2, Ventilation Rate Procedure, shall be permitted. |
403.2.1 Recirculation of air. The air required by Section 403.3 shall not be recirculated. Air in excess of that required by Section 403.3 shall not be prohibited from being recirculated as a component of supply air to building spaces, except that:
1. Ventilation air shall not be recirculated from one dwelling to another or to dissimilar occupancies.
2. Supply air to a swimming pool and associated deck areas shall not be recirculated unless such air is dehumidified to maintain the relative humidity of the area at 60 percent or less. Air from this area shall not be recirculated to other spaces where 10 percent or more of the resulting supply airstream consists of air recirculated from these spaces.
3. Where mechanical exhaust is required by Note b in Table 403.3.1.1, recirculation of air from such spaces shall be prohibited. All air supplied to such spaces shall be exhausted, including any air in excess of that required by Table 403.3.1.1.
4. Where mechanical exhaust is required by Note g in Table 403.3.1.1, mechanical exhaust is required and recirculation from such spaces is prohibited where more than 10 percent of the resulting supply airstream consists of air recirculated from these spaces. Return air from such spaces shall only be permitted to be recirculated when returned to an energy recovery ventilation system complying with Section 514. Recirculation of air that is contained completely within such spaces shall not be prohibited.
403.3Outdoor air and local exhaust airflow rates. Group R occupancies shall be provided with outdoor air and local exhaust in accordance with Section 403.4. All other buildings intended to be occupied shall be provided with outdoor air and local exhaust in accordance with Section 403.3.1.
403.3.1.1 Outdoor airflow rate. Ventilation systems shall be designed to have the capacity to supply the minimum outdoor airflow rate determined in accordance with this section. In each occupiable space, the ventilation system shall be designed to deliver the required rate of outdoor airflow to the breathing zone. Outdoor air shall be supplied directly to each occupiable space from an air handling unit through a fully ducted path or ducted to within 12 inches of the return air opening of a fan-powered terminal unit used to transfer the outdoor air to the occupiable space. The occupant load utilized for design of the ventilation system shall not be less than the number determined from the estimated maximum occupant load rate indicated in Table 403.3.1.1. Ventilation rates for occupancies not represented in Table 403.3.1.1 shall be those for a listed occupancy classification that is most similar in terms of occupant density, activities and building construction; or shall be determined by an approved engineering analysis. The ventilation system, including transfer fan-powered terminal units shall be designed to supply the required rate of ventilation air continuously during the period the building is occupied, except as otherwise stated in other provisions of the code.
With the exception of smoking lounges, the ventilation rates in Table 403.3.1.1 are based on the absence of smoking in occupiable spaces. Where smoking is anticipated in a space other than a smoking lounge, the ventilation system serving the space shall be designed to provide ventilation over and above that required by Table 403.3.1.1 in accordance with accepted engineering practice.
EXCEPTION: | Where occupancy density is known and documented in the plans, the outside air rate may be based on the design occupant density. Under no circumstance shall the occupancies used result in outside air less than one-half that resulting from application of Table 403.3.1.1 estimated maximum occupancy rates. |
Table 403.3.1.1
REQUIRED OUTDOOR VENTILATION AIR
(The following categories in Table 403.3.1.1 have been modified. The remainder remain as printed in the 2018 International Mechanical Code)
Occupancy Classification | Occupant Density #/1000 ft2a | People Outdoor Airflow Rate in Breathing Zone Rp cfm/Person | Area Outdoor Airflow Rate in Breathing Zone Ra cfm/ft2a | Exhaust Airflow Rate cfm/ft2a |
Offices | | | | |
| Conference rooms | 50 | 5 | 0.06 | — |
| Kitchenettesk | 25 | 5 | 0.06 | 0.30 |
| Office spaces | 5 | 5 | 0.06 | — |
| Reception areas | 30 | 5 | 0.06 | — |
| Telephone/data entry | 60 | 5 | 0.06 | — |
| Main entry lobbies | 10 | 5 | 0.06 | — |
Private dwellings, single and multiple | | | | |
| Garages, common for multiple unitsb | — | — | — | 0.75 |
| | | | | See Table 403.4.7 |
| Living areasc | | See Table 403.4.2 | — | — |
| Toilet rooms((,))and bathrooms ((and laundry areas))g((, i)) | — | — | | See Table 403.4.7 |
Public spaces | | | | |
| Corridors serving other than Group R occupancies | — | — | 0.06 | — |
| Corridors serving Group R dwelling or sleeping units with whole house exhaust system | — | — | 0.12 | — |
| Corridors serving Group R dwelling or sleeping units with other than whole house exhaust system | — | — | 0.06 | — |
| Courtrooms | 70 | 5 | 0.06 | — |
| Elevator car | — | — | — | 1 |
| Elevator lobbies in parking garage | — | — | 1.0 | — |
| Legislative chambers | 50 | 5 | 0.06 | — |
| Libraries | 10 | 5 | 0.12 | — |
| Museums (children's) | 40 | 7.5 | 0.12 | — |
| Museums/galleries | 40 | 7.5 | 0.06 | — |
| Places of religious worship | 120 | 5 | 0.06 | — |
| Shower room (per showerhead)g | — | — | — | 50/20f |
| Smoking loungesb | 70 | 60 | — | — |
| Toilet rooms—Publicg | — | — | — | 50/70e |
Sports and amusement | | | | |
| Disco/dance floors | 100 | 20 | 0.06 | — |
| Bowling alleys (seating areas) | 40 | 10 | 0.12 | — |
| Game arcades | 20 | 7.5 | 0.18 | — |
| Ice arenas, without combustion enginesj | — | — | 0.30 | 0.5 |
| Gym, stadium, arena (play area)j | — | — | 0.30 | — |
| Spectator areas | 150 | 7.5 | 0.06 | — |
| Swimming pools (pool and deck area) | — | — | 0.48 | — |
| Health club/aerobics room | 40 | 20 | 0.06 | — |
| Health club/weight room | 10 | 20 | 0.06 | — |
Storage | | | | |
| Janitor closets, trash rooms, recycling rooms | — | — | — | 1.0 |
| Repair garages, enclosed parking garageb, d | — | — | — | 0.75 |
| Storage rooms, chemical | — | — | — | 1.5 |
| Warehouses | — | — | 0.06 | — |
Workrooms | | | | |
| Bank vaults/safe deposit | 5 | 5 | 0.06 | — |
| Darkrooms | — | — | — | 1.0 |
| Copy, printing rooms | 4 | 5 | 0.06 | 0.5 |
| Freezer and refrigerated spaces (<50°F) | 0 | 10 | 0 | 0 |
| Meat processingc | 10 | 15 | — | — |
| Pharmacy (prep. area) | 10 | 5 | 0.18 | — |
| Photo studios | 10 | 5 | 0.12 | — |
| Computer (without printing) | 4 | 5 | 0.06 | — |
For SI: | | 1 cubic foot per minute = 0.0004719 m3/s, 1 ton = 908 kg, 1 cubic foot per minutes per square foot = 0.00508 m3/(s•m2), °C = [(°F) -32]/1.8, 1 square foot - 0.0929 m2. |
a. | | Based upon net occupiable floor area. |
b. | | Mechanical exhaust required and the recirculation of air from such spaces is prohibited. Recirculation of air that is contained completely within such spaces shall not be prohibited (see Section 403.2.1, Item 3). |
c. | | Spaces unheated or maintained below 50°F are not covered by these requirements unless the occupancy is continuous. |
d. | | Ventilation systems in enclosed parking garages shall comply with Section 404. |
e. | | Rates are per water closet or urinal. The higher rate shall be provided where the exhaust system is designed to operate intermittently. The lower rate shall be permitted only where the exhaust system is designed to operate continuously while occupied. |
f. | | Rates are per room unless otherwise indicated. The higher rate shall be provided where the exhaust system is designed to operate intermittently. The lower rate shall be permitted only where the exhaust system is designed to operate continuously while occupied. |
g. | | Mechanical exhaust is required and recirculation from such spaces is prohibited except that recirculation shall be permitted where the resulting supply airstream consists of not more than 10 percent air recirculated from these spaces. Return air from such spaces only be permitted to be recirculated when returned to an energy recovery ventilation system complying with Section 514. Recirculation of air that is contained completely within such spaces shall not be prohibited (see Section 403.2.1, Items 2 and 4). |
h. | | For nail salons, each manicure and pedicure station shall be provided with a source capture system capable of exhausting not less than 50 cfm per station. Exhaust inlets shall be located in accordance with Section 502.20. Where one or more required source capture systems operate continuously during occupancy, the exhaust rate from such systems shall be permitted to be applied to the exhaust flow rate required by Table 403.3.1.1 for the nail salon. |
i. | | ((A laundry area within a kitchen or bathroom is not required to have local exhaust. For the laundry area to qualify as being within the kitchen, the laundry room door must open directly into the kitchen and not into an adjacent corridor. Where there are doors that separate the laundry area from the kitchen or bathroom the door shall be louvered.))Reserved. |
j. | | When combustion equipment is intended to be used on the playing surface, additional dilution ventilation and/or source control shall be provided. |
k. | | Kitchenettes require exhaust when they contain a domestic cooking appliance range or oven that is installed in accordance with Table 507.2.1. Kitchenettes that only contain a microwave cooking appliance are not required to have exhaust. A kitchenette may not contain commercial cooking appliances that require Type I or Type II exhaust as these occupancies are required to be exhausted to the kitchen category in Table 403.3.1.1. |
403.3.1.1.2.3 Multiple zone recirculating systems. For ventilation systems wherein one or more air handlers supply a mixture of outdoor air and recirculated air to more than one ventilation zone, the outdoor air intake flow (Vot) shall be determined in accordance with Sections 403.3.1.1.2.3.1 through 403.3.1.1.2.3.4.
403.3.1.1.2.3.1 Uncorrected outdoor air intake. The uncorrected outdoor air intake flow (Vot) shall be determined in accordance with Equation 4-5.
Vou = D∑all zones(Rp × Pz) + ∑all zones(Ra × Az)(Equation 4-5)
403.3.1.1.2.3.1.1 Occupant diversity. The occupant diversity ratio (D) shall be determined in accordance with Equation 4-6 to account for variations in population within the ventilation zones served by the system.
D = Ps/∑all zonesPz(Equation 4-6)
where:
Ps = System population: The total population in the area served by the system.
EXCEPTION: | Alternative methods to account for occupant diversity shall be permitted, provided the resulting Vouvalue is no less than that determined using Equation 4-5. |
403.3.1.1.2.3.1.2 Design system population. Design system population (Ps) shall equal the largest (peak) number of people expected to occupy all ventilation zones served by the ventilation system during use.
Note: Design system population is always equal to or less than the sum of design zone population for all zones in the area served by the system because all zones may or may not be simultaneously occupied at design population.
403.3.1.1.2.3.2 System ventilation efficiency. The system ventilation efficiency (Ev) shall be determined in accordance with Section 403.3.1.1.2.3.3 for the Simplified Procedure or Appendix A of ASHRAE 62.1 for the Alternative Procedure.
Note: These procedures also establish zone minimum primary airflow rates for VAV systems.
403.3.1.1.2.3.3 Simplified procedure.
403.3.1.1.2.3.3.1 System ventilation efficiency. System ventilation efficiency (Ev) shall be determined in accordance with Equation 4-6a or 4-6b.
Ev = 0.88 × D + 0.22 for D < 0.60 (Equation 4-6a)
Ev = 0.75 for D ≥ 0.60 (Equation 4-6b)
403.3.1.1.2.3.3.2 Zone minimum primary airflow. For each zone, the minimum primary airflow (Vpz-min) shall be determined in accordance with Equation 4-7.
Vpz-min = Voz × 1.5 (Equation 4-7)
403.3.1.1.2.3.4 Outdoor air intake. The design outdoor air intake flow (Vot) shall be determined in accordance with Equation 4-8.
Vot = Vou/Ev(Equation 4-8)
403.3.2 Group R-2, R-3 and R-4 occupancies. This section is not adopted. See Section 403.4.
403.3.2.1 Outdoor air for dwelling units. This section is not adopted.
403.3.2.2 Outdoor air for other spaces. This section is not adopted.
403.3.2.3 Local exhaust. This section is not adopted.
403.4 Group R whole house mechanical ventilation system. Each dwelling unit or sleeping unit shall be equipped with a whole house mechanical ventilation system that complies with Sections 403.4.1 through 403.4.6. Each dwelling unit or sleeping unit shall be equipped with local exhaust complying with Section 403.4.7. All occupied spaces, including public corridors, other than the Group R dwelling units and/or sleeping units, that support these Group R occupancies shall meet the ventilation requirement of natural ventilation requirements of Section 402 or the mechanical ventilation requirements of Sections 403.1 through 403.3.
403.4.1 System design. The whole house ventilation system shall consist of one or more supply fans, one or more exhaust fans, or an ERV/HRV with integral fans; and the associated ducts and controls. Local exhaust fans shall be permitted to serve as part of the whole house ventilation system when provided with the proper controls in accordance with Section 403.4.5. The systems shall be designed and installed to supply and exhaust the minimum outdoor airflow rates per Section 403.4.2 as corrected by the balanced and/or distributed whole house ventilation system coefficients in accordance with Section 403.4.3 where applicable.
Table 403.4.2
WHOLE HOUSE MECHANICAL VENTILATION AIRFLOW RATE
(CONTINUOUSLY OPERATING SYSTEMS)
Floor Area (ft2) | | Bedrooms1 | |
1 | | 2 | | 3 | | 4 | | ˃5 | |
<500 | | 30 | | 30 | | 35 | | 45 | | 50 | |
500 - 1000 | | 30 | | 35 | | 40 | | 50 | | 55 | |
1001 - 1500 | | 30 | | 40 | | 45 | | 55 | | 60 | |
1501 - 2000 | | 35 | | 45 | | 50 | | 60 | | 65 | |
2001 - 2500 | | 40 | | 50 | | 55 | | 65 | | 70 | |
2501 - 3000 | | 45 | | 55 | | 60 | | 70 | | 75 | |
3001 - 3500 | | 50 | | 60 | | 65 | | 75 | | 80 | |
3501 - 4000 | | 55 | | 65 | | 70 | | 80 | | 85 | |
4001 - 4500 | | 60 | | 70 | | 75 | | 85 | | 90 | |
4501 - 5000 | | 65 | | 75 | | 80 | | 90 | | 95 | |
1 Minimum airflow (Qr) is set at not less than 30 cfm for each dwelling units. |
403.4.2 Whole house mechanical ventilation rates. The sleeping unit whole house mechanical ventilation minimum outdoor airflow rate shall be determined in accordance with the breathing zone ventilation rates minimum outdoor airflow rate shall be determined in accordance with the breathing zone ventilation rates requirements of Section 403.3.1.1.1.2 using Equation 4-2. The dwelling unit whole house mechanical ventilation minimum outdoor airflow rate shall be determined in accordance with Equation 4-10 or Table 403.4.2.
Qr = 0.01*Afloor + 7.5*(Nbr + 1) (Equation 4-10)
where: |
Qr | = | Ventilation airflow rate, cubic feet per minute (cfm) but not less than 30 cfm for each dwelling unit. |
Afloor | = | Conditioned floor area, square feet (ft2) |
Nbr | = | Number of bedrooms, not less than one. |
Table 403.4.3
SYSTEM COEFFICIENT (Csystem)
System Type | Distributed | Not Distributed |
Balanced | 1.0 | 1.25 |
Not Balanced | 1.25 | 1.5 |
403.4.3 Ventilation quality adjustment. The minimum whole house ventilation rate from Section 403.4.2 shall be adjusted by the system coefficient in Table 403.4.3 based on the system type not meeting the definition of a balanced whole house ventilation system and/or not meeting the definition of a distributed whole house ventilation system.
Qv = Qr* Csystem(Equation 4-11)
where: |
Qv | = | Quality-adjusted ventilation airflow rate in cubic feet per minute (cfm) |
Qr | = | Ventilation airflow rate, cubic feet per minute (cfm) from Equation 4-10 or Table 403.4.1 |
Csystem | = | System coefficient from Table 403.4.3 |
403.4.4 Whole house ventilation residential occupancies. Residential dwelling and sleeping unit whole house ventilation systems shall meet the requirements of Sections 403.4.4.1 or 403.4.4.2 depending on the occupancy of the residential unit.
403.4.4.1 Whole house ventilation in Group R-2 occupancies. Residential dwelling and sleeping units in Group R-2 occupancies system shall include supply and exhaust fans and be a balanced whole house ventilation system in accordance with Section 403.4.6.3. The system shall include a heat or energy recovery ventilator with a sensible heat recovery effectiveness as prescribed in Section C403.3.6 of the Washington State Energy Code. The whole house ventilation system shall operate continuously at the minimum ventilation rate determined in accordance with Section 403.4. The whole house supply fan shall provide ducted outdoor ventilation air to each habitable space within the residential unit.
403.4.4.2 Whole house ventilation for other than Group R-2 occupancies. Residential dwelling and sleeping units in other than Group R-2 occupancies, including I-1 condition 2 occupancies, shall have a whole house mechanical ventilation system with supply and exhaust fans in accordance with Section 403.4.6.1, 403.4.6.2, 403.4.6.3, or 403.4.6.4. The whole house ventilation system shall operate continuously at the minimum ventilation rate determined in accordance with Section 403.4.2 unless configured with intermittent off controls in accordance with Section 403.4.6.5. The whole house supply fan shall provide ducted outdoor ventilation air to each habitable space within the residential unit.
403.4.5 Whole house ventilation controls.
1. The whole house ventilation system shall be controlled with manual switches, timers or other means that provide for automatic operation of the ventilation system that are readily accessible by the occupant;
2. Whole house mechanical ventilation system shall be provided with controls that enable manual override off of the system by the occupant during periods of poor outdoor air quality. Controls shall include permanent text or a symbol indicating their function. Recommended control permanent labeling to include text similar to the following: "Leave on unless outdoor air quality is very poor." Manual controls shall be provided with ready access for the occupant.
EXCEPTION: | Central whole house mechanical systems with supply air and/or exhaust that serve more than one dwelling or sleep units are not required to have manual override off controls accessible to the occupant. |
3. Whole house ventilation systems shall be configured to operating continuously except where intermittent off controls are provided in accordance with Section 403.4.6.5 and allowed by Section 403.4.4.2.
403.4.6 Whole house ventilation system component requirements. Whole house ventilation supply and exhaust fans specified in this section shall have a minimum efficacy as prescribed in the Washington State Energy Code. The fans shall be rated for sound at a maximum of 1.0 sone at design airflow and static pressure conditions. Design and installation of the system or equipment shall be carried out in accordance with manufacturer's installation instructions.
EXCEPTIONS: | 1. Central supply or exhaust fans serving multiple residential units do not need to comply with the maximum fan sone requirements. |
| 2. Interior joining spaces provided with a 30 cfm transfer fan or a 25 square foot permanent opening do not require supply ventilation air directly to the space. Transfer fans shall meet the sone rating above and have whole house ventilation controls in accordance with Section 403.4.5. |
403.4.6.1 Exhaust fans. Exhaust fans required shall be ducted directly to the outside in accordance with Section 501.3. Exhaust air outlets shall be designed to limit the pressure difference to the outside to limiting the outlet free area maximum velocity to 500 feet per minute and equipped with backdraft dampers or motorized dampers in accordance with Washington State Energy Code. Exhaust fans shall be tested and rated in accordance with HVI 915, HVI 916, and HVI 920. Exhaust fans required in this section may be used to provide local ventilation. Exhaust fans that are designed for intermittent exhaust airflow rates higher than the continuous exhaust airflow rates in Table 403.4.2 shall be provided with occupancy sensors or humidity sensors to automatically override the fan to the high speed airflow rate. The exhaust fans shall be tested and the testing results shall be submitted and posted in accordance with Section 403.4.6.7.
EXCEPTION: | Central exhaust fans serving multiple residential units do not need to comply with the HVI testing requirements. |
403.4.6.2 Supply fans. Supply fans used in meeting the requirements of this section shall supply outdoor air from intake openings in accordance with Sections 401.4 and 401.5. Intake air openings shall be designed to limit the pressure difference to the outside to limiting the inlet free area maximum velocity to 500 feet per minute and when designed for intermittent off operation shall be equipped with motorized dampers in accordance with the Washington State Energy Code. Supply fans shall be tested and rated in accordance with HVI 915, HVI 916, and HVI 920. Where outdoor air is provided to each habitable dwelling unit or sleeping unit by supply fan systems the outdoor air shall be filtered. The filter shall be provided with access for regular maintenance and replacement. The filter shall have a Minimum Efficiency Rating Value (MERV) of at least 8.
EXCEPTION: | Central supply fans serving multiple residential units do not need to comply with the HVI testing requirements. |
403.4.6.3 Balanced whole house ventilation system. A balanced whole house ventilation system shall include both supply and exhaust fans. The supply and exhaust fans shall have airflow that is within 10 percent of each other. The tested and balanced total mechanical exhaust airflow rate is within 10 percent or 5 cfm, whichever is greater, of the total mechanical supply airflow rate. The flow rate test results shall be submitted and posted in accordance with Section 403.4.6.7. The exhaust fan shall meet the requirements of Section 403.4.6.1. The supply fan shall meet the requirements of Section 403.4.6.2. For R-2 dwelling and sleeping units, the system is required to have balanced whole house ventilation but is not required to have distributed whole house ventilation where the not distributed system coefficient from Table 403.4.3 is utilized to correct the whole house mechanical ventilation rate. The system shall be design and balanced to meet the pressure equalization requirements of Section 501.4. Intermittent dryer exhaust, intermittent range hood exhaust, and intermittent toilet room exhaust airflow rates above the residential dwelling or sleeping unit minimum ventilation rate are exempt from the balanced airflow calculation.
403.4.6.4 Furnace integrated supply. Systems using space condition heating and/or cooling air handler fans for outdoor air supply air distribution are not permitted.
EXCEPTION: | Air handler fans shall be permitted that have multi-speed or variable speed supply airflow control capability with a low speed operation not greater than 25 percent of the rated supply air flow capacity during ventilation only operation. Outdoor air intake openings must meet the provisions of Sections 401.4 and 401.5 and must include a motorized damper that is activated by the whole house ventilation system controller. Intake air openings shall be designed to limit the pressure difference to the outside to limiting the inlet free area maximum velocity to 500 ft per min. The motorized damper must be controlled to maintain the outdoor airflow intake airflow within 10 percent of the whole house mechanical exhaust airflow rate. The supply air handler shall provide supply air to each habitable space in the residential unit. The whole house ventilation system shall include exhaust fans in accordance with Section 403.4.6.1 to meet the pressure equalization requirements of Section 501.4. The flow rate for the outdoor air intake must be tested and verified at the minimum ventilation fan speed and the maximum heating or cooling fan speed. The results of the test shall be submitted and posted in accordance with Section 403.4.6.7. |
403.4.6.5 Intermittent off operation. Whole house mechanical ventilation systems shall be provided with advanced controls that are configured to operate the system with intermittent off operation and shall operate for a least two hours in each four-hour segment. The whole house ventilation airflow rate determined in accordance with Section 403.4.2 as corrected by Section 403.4.3 shall be multiplied by the factor determined in accordance with Table 403.4.6.5.
Table 403.4.6.5
INTERMITTENT WHOLE HOUSE MECHANICAL VENTILATION RATE FACTORSa,b
Run-time Percentage in Each 4-hour Segment | 50% | 66% | 75% | 100% |
Factora | 2 | 1.5 | 1.3 | 1.0 |
a | For ventilation system run-time values between those given, the factors are permitted to be determined by interpolation. |
b | Extrapolation beyond the table is prohibited. |
403.4.6.6 Testing. Whole house mechanical ventilation systems shall be tested, balanced and verified to provide a flow rate not less than the minimum required by Sections 403.4.2 and 403.4.3. Testing shall be performed according to the ventilation equipment manufacturer's instructions, or by using a flow hood, flow grid, or other airflow measuring device at the mechanical ventilation fan's inlet terminals, outlet terminals or grilles or in the connected ventilation ducts. Where required by the building official, testing shall be conducted by an approved third party. A written report of the results of the test shall be signed by the party conducting the test and provided to the building official and shall be posted in the residential unit in accordance with Section 403.4.6.7.
403.4.6.7 Certificate. A permanent certificate shall be completed by the mechanical contractor, test and balance contractor or other approved party and posted on a wall in the space where the furnace is located, a utility room, or an approved location inside the building. When located on an electrical panel, the certificate shall not cover or obstruct the visibility of the circuit directory label, service disconnect label, or other required labels. The certificate shall list the flow rate determined from the delivered airflow of the whole house mechanical ventilation system as installed and the type of mechanical whole house ventilation system used to comply with Section 403.4.3.
403.4.7 Local exhaust. Bathrooms, toilet rooms and kitchens shall include a local exhaust system. Such local exhaust systems shall have the capacity to exhaust the minimum airflow rate in accordance with Table 403.4.7 and Table 403.3.1.1, including notes. Fans required by this section shall be provided with controls that enable manual override or automatic occupancy sensor, humidity sensor or pollutant sensor controls. An "on/off" switch shall meet this requirement for manual controls. Manual fan controls shall be provided with ready access in the room served by the fan.
Table 403.4.7
MINIMUM EXHAUST RATES
Area to be exhausted | Exhaust Rate |
Intermittent | Continuous |
Kitchens | 100 cfm | 30 cfm |
Bathrooms - Toilet rooms | 50 cfm | 20 cfm |
403.4.7.1 Whole house exhaust controls. If the local exhaust fan is included in a whole house ventilation system in accordance with Section 403.4.6, the exhaust fan shall be controlled to operate as specified in Section 403.4.5.
403.4.7.2 Local exhaust fans. Exhaust fans shall meet the following criteria.
1. Exhaust fans shall be tested and rated in accordance with HVI 915, HVI 916, and HVI 920.
EXCEPTION: | Where a range hood or down draft exhaust fan is used for local exhaust for a kitchen, the device is not required to be rated per these standards. |
2. Fan airflow rating and duct system shall be designed and installed to deliver at least the exhaust airflow required by Table 403.4.7. The airflows required refer to the delivered airflow of the system as installed and tested using a flow hood, flow grid, or other airflow measurement device. Local exhaust systems shall be tested, balanced and verified to provide a flow rate not less than the minimum required by this section.
3. Design and installation of the system or equipment shall be carried out in accordance with manufacturers' installation instructions.
4. Fan airflow rating and duct system shall be designed and installed to deliver at least the exhaust airflow required by Table 403.4.3.
EXCEPTIONS: | 1. An exhaust airflow rating at a pressure of 0.25 in. w.g. may be used, provided the duct sizing meets the prescriptive requirements of Table 403.4.7.2. |
| 2. Where a range hood or down draft exhaust fan is used to satisfy the local ventilation requirements for kitchens, the range hood or down draft exhaust shall not be less than 100 cfm at 0.10 in. w.g. |
Table 403.4.7.2
PRESCRIPTIVE EXHAUST DUCT SIZING
Fan Tested cfm at 0.25 inches w.g. | Minimum Flex Diameter | Maximum Length in Feet | Minimum Smooth Diameter | Maximum Length in Feet | Maximum Elbowsa |
50 | | 4 inches | | 25 | 4 inches | | 70 | 3 | |
50 | | 5 inches | | 90 | 5 inches | | 100 | 3 | |
50 | | 6 inches | | No Limit | 6 inches | | No Limit | 3 | |
80 | | 4 inchesb | | NA | 4 inches | | 20 | 3 | |
80 | | 5 inches | | 15 | 5 inches | | 100 | 3 | |
80 | | 6 inches | | 90 | 6 inches | | No Limit | 3 | |
100 | | 5 inchesb | | NA | 5 inches | | 50 | 3 | |
100 | | 6 inches | | 45 | 6 inches | | No Limit | 3 | |
125 | | 6 inches | | 15 | 6 inches | | No Limit | 3 | |
125 | | 7 inches | | 70 | 7 inches | | No Limit | 3 | |
a. | For each additional elbow, subtract 10 feet from length. |
b. | Flex ducts of this diameter are not permitted with fans of this size. |
AMENDATORY SECTION(Amending WSR 20-03-041, filed 1/8/20, effective 7/1/20)
WAC 51-52-0601Section 601—General.
601.2 Air movement in egress elements. Corridors shall not serve as supply, return, exhaust, relief or ventilation air ducts.
EXCEPTIONS: | 1. Use of a corridor as a source of makeup air for exhaust systems in rooms that open directly onto such corridors, including toilet rooms, bathrooms, dressing rooms, smoking lounges and janitor closets, shall be permitted provided that each such corridor is directly supplied with outdoor air at a rate greater than the rate of makeup air taken from the corridor. |
| 2. Where located within a dwelling unit, the use of corridors for conveying return air shall not be prohibited. |
| 3. Where located within tenant spaces of one thousand square feet (93 m2) or less in area, utilization of corridors for conveying return air is permitted. |
| 4. Incidental air movement from pressurized rooms within health care facilities, provided that the corridor is not the primary source of supply or return to the room. |
| 5. Where such air is part of an engineered smoke control system. |
| 6. Air supplied to corridors serving residential occupancies shall not be considered as providing ventilation air to the dwelling units and sleeping units subject to the following: |
| 6.1 The air supplied to the corridor is one hundred percent outside air; and |
| 6.2 The units served by the corridor have conforming ventilation air independent of the air supplied to the corridor; and |
| 6.3 For other than high-rise buildings, the supply fan will automatically shut off upon activation of corridor smoke detectors installed in accordance with Section 606.2.4; or |
| 6.4 For high-rise buildings, the supply fan will automatically shut off upon activation of the smoke detectors required by International Fire Code Section 907.2.12.1 or upon receipt of another approved fire alarm signal. The supply fan is not required to be automatically shut off when used as part of an approved building stairwell or elevator hoistway pressurization system. Corridor smoke detectors shall be installed in accordance with Section 606.2.5. |
((606.2.4 Corridors serving Group R occupancies in other than high-rise buildings. Corridors that serve Group R occupancies in other than high-rise buildings and that are mechanically ventilated with supply air shall be equipped with smoke detectors spaced in accordance with NFPA 72. The supply fan shall automatically shut off upon activation of the corridor smoke detectors.
EXCEPTION: | Corridor smoke detection is not required when air is returned back to the supply fan from the corridor and return air smoke detectors are installed in the return air duct or plenum upstream of any filters, exhaust air connections, outdoor air connections, or decontamination equipment and appliances designed to automatically shut off the supply fan. |
606.2.5 Corridors serving Group R occupancies in high-rise buildings. Corridors that serve Group R occupancies in high-rise buildings and that are mechanically ventilated with supply air shall be equipped with smoke detectors that are spaced in accordance with NFPA 72 and air supply inlets to the corridor shall be provided with smoke/fire dampers. The supply inlet smoke/fire dampers shall automatically close upon activation of the corridor smoke detectors.
EXCEPTIONS: | 1. Corridor smoke detection is not required to close the supply inlet smoke/fire dampers when the smoke/fire dampers are used as part of an approved building stairwell or elevator hoistway pressurization smoke control system. |
| 2. Corridor smoke detection is not required when air is returned back to the supply fan from the corridor and return air smoke detectors are installed in the return air duct or plenum upstream of any filters, exhaust air connections, outdoor air connections, or decontamination equipment and appliances designed to automatically shut off the supply fan.)) |
AMENDATORY SECTION(Amending WSR 16-01-148, filed 12/21/15, effective 7/1/16)
WAC 51-52-0606Section 606—Smoke detection systems control.
606.2.1 Return air systems. Smoke detectors shall be installed in return air systems with a design capacity greater than 2,000 cfm (0.9 m3/s), in the return air duct or plenum upstream of any filters, exhaust air connections, outdoor air connections, or decontamination equipment and appliances.
EXCEPTIONS: | 1. Smoke detectors are not required in the return air system where all portions of the building served by the air distribution system are protected by area smoke detectors connected to a fire alarm system in accordance with the International Fire Code. The area smoke detection system shall comply with Section 606.4. |
| 2. Smoke detectors are not required in the air system where all of the air is exhausted and not recirculated back to any portion of the building. Additionally, smoke detectors are not required in the supply system that provides the make-up air for the exhaust system. |
606.2.2 Common supply and return air systems. Where multiple air-handling systems share common supply or return air ducts or plenums with a combined design capacity greater than 2,000 cfm (0.9 m3/s), the return air system shall be provided with smoke detectors in accordance with Section 606.2.1.
EXCEPTION: | Individual smoke detectors shall not be required for each fan-powered terminal unit, provided that such units do not have an individual design capacity greater than 2,000 cfm (0.9 m3/s) and will be shut down by activation of one of the following: |
| 1. Smoke detectors required by Sections 606.2.1 and 606.2.3. |
| 2. An approved area smoke detector system located in the return air plenum serving such units. |
| 3. An area smoke detector system as prescribed in the exception to Section 606.2.1. |
In all cases, the smoke detectors shall comply with Sections 606.4 and 606.4.1.
The shut down of fan-powered terminal units may be performed by a building automation system upon activation of smoke detection as described in Section 606.2.2, Exception Items 1, 2, or 3. The building automation system is not required to be listed as a smoke control system and is not required to comply with UL ((Standard 864: Standard for Control Units and Accessories for Fire Alarm Systems))864.
606.2.4 Corridors serving Group R occupancies in other than high-rise buildings. Corridors that serve Group R occupancies in other than high-rise buildings and that are mechanically ventilated with supply air shall be equipped with smoke detectors spaced in accordance with NFPA 72. The supply fan shall automatically shut off upon activation of the corridor smoke detectors.
EXCEPTION: | Corridor smoke detection is not required when air is returned back to the supply fan from the corridor and return air smoke detectors are installed in the return air duct or plenum upstream of any filters, exhaust air connections, outdoor air connections, or decontamination equipment and appliances designed to automatically shut off the supply fan. |
606.2.5 Corridors serving Group R occupancies in high-rise buildings. Corridors that serve Group R occupancies in high-rise buildings and that are mechanically ventilated with supply air shall be equipped with smoke detectors that are spaced in accordance with NFPA 72 and air supply inlets to the corridor shall be provided with smoke/fire dampers. The supply inlet smoke/fire dampers shall automatically close upon activation of the corridor smoke detectors.
EXCEPTIONS: | 1. Corridor smoke detection is not required to close the supply inlet smoke/fire dampers when the smoke/fire dampers are used as part of an approved building stairwell or elevator hoistway pressurization smoke control system. 2. Corridor smoke detection is not required when air is returned back to the supply fan from the corridor and return air smoke detectors are installed in the return air duct or plenum upstream of any filters, exhaust air connections, outdoor air connections, or decontamination equipment and appliances designed to automatically shut off the supply fan. |
NEW SECTION
WAC 51-52-1101Section 1101—Refrigeration, general.
1101.2 Factory-built equipment and appliances.Listed and labeled self-contained, factory-built equipment and appliances shall be tested in accordance with UL 207, 412, 471, 1995, or 60335-2-40. Such equipment and appliances are deemed to meet the design, manufacture and factory test requirements of this code if installed in accordance with their listing and the manufacturer's instructions.
1101.6 General. Refrigeration systems shall comply with the requirements of this code and, except as modified by this code, ASHRAE 15. Ammonia-refrigerating systems shall comply with this code and, except as modified by this code, ASHRAE 15, IIAR 2, IIAR 3, IIAR 4, and IIAR 25.
EXCEPTION: | Systems utilizing A2L refrigerants complying with ASHRAE 15 are deemed to meet this code. |
AMENDATORY SECTION(Amending WSR 21-05-020, filed 2/8/21, effective 3/11/21)
WAC 51-52-1200Chapter 12—Hydronic piping.
1209.5 Thermal barrier required. Radiant floor heating and snow melt systems shall be provided with a thermal barrier in accordance with Sections 1209.5.1 and 1209.5.2. Concrete slab-on-grade, asphalt and paver-system type pavements shall have a minimum of R-10 insulation installed under the area to be snow melted, or R-5 insulation shall be installed under and at the slab edges of the area to be snow melted. The insulation shall be located underneath the snow and ice melt hydronic piping or cable and along all edges of the pavement where the snow and ice melt system is installed in accordance with the snow and ice melt manufacturer's instructions. Insulation R-values for slab-on-grade and suspended floor insulation shall be in accordance with the Washington State Energy Code.
((1209.5.1 Slab-on-grade installation. Radiant piping utilized in slab-on-grade applications shall be provided with insulating materials installed beneath the piping as required by the Washington State Energy Code.))
1210.7.6 Expansion tanks. Shutoff valves shall be installed at connections to expansion tanks. A method of draining the expansion tank downstream of the shutoff valve shall be provided.
AMENDATORY SECTION(Amending WSR 21-05-020, filed 2/8/21, effective 3/11/21)
WAC 51-52-1500Chapter 15—Referenced standards.
The following referenced standards are added to Chapter 15.
((ANSI
UL 60335-2-40))
ANCE
UL/CSA/ANCE 60335-2-40—2019 Household and Similar Electrical Appliances - Safety - Part 2-40: Particular Requirements for Electrical Heat Pumps, Air Conditioners and
Dehumidifiers . . . . 1101.2
ASHRAE
15-2019 Safety Standards for Refrigeration
Systems. . . .1101.6, 1105.8, 1108.1
34-2019((Safety standards for refrigeration systems and))Designation and classification of
refrigerants((.)). . . .202, 1102.2.1, 1103.1
62.2-2016 Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings. . . .403.4.11
CSA
UL/CSA/ANCE 60335-2-40—2019 Household and Similar Electrical Appliances - Safety - Part 2-40: Particular Requirements for Electrical Heat Pumps, Air Conditioners and
Dehumidifiers. . . .1101.2
HVI address:
Home Ventilating Institute
1740 Dell Range Blvd., Suite H, PMB 450
Cheyenne, WY 82009
HVI 915-2015 Procedure for Loudness Testing of Residential Fan Products. . . .403.4.6.1, 403.4.6.2, 403.4.7.2
HVI 916-2015 Air Flow Test Procedure. . . .403.4.6.1, 403.4.6.2, 403.4.7.2
HVI 920-2015 Product Performance Certification Procedure Including Verification and Challenge. . . .403.4.6.1, 403.4.6.2, 403.4.7.2
UL
864-03 Control Units and Accessories for Fire Alarm Systems with revisions through December 2014. . . .606.2.2
UL/CSA/ANCE 60335-2-40—2019 Household and Similar Electrical Appliances - Safety - Part 2-40: Particular Requirements for Electrical Heat Pumps, Air Conditioners and
Dehumidifiers. . . .1101.2