PERMANENT RULES
Effective Date of Rule: July 1, 2007.
Purpose: To amend chapter 51-13 WAC, Washington state ventilation and indoor air quality code.
Citation of Existing Rules Affected by this Order: Amending 2.
Statutory Authority for Adoption: RCW 19.27.190 and 19.27.020
Other Authority: Chapters 19.27 and 34.05 RCW.
Adopted under notice filed as WSR 06-16-109 on August 1, 2006.
Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 1, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.
Number of Sections Adopted at Request of a Nongovernmental Entity: New 0, Amended 1, Repealed 0.
Number of Sections Adopted on the Agency's Own Initiative: New 0, Amended 1, Repealed 0.
Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.
Number of Sections Adopted Using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 2, Repealed 0.
Date Adopted: November 17, 2006.
John Neff
Council Chair
OTS-8986.1
AMENDATORY SECTION(Amending WSR 04-07-192, filed 3/24/04,
effective 7/1/04)
WAC 51-13-304
Mechanical ventilation criteria and
minimum ventilation performance for all other occupancies not
covered in sections 302 and 303.
304.1 Ventilation: The minimum requirements for operable
area to provide natural ventilation are specified in the
International Building Code (IBC) as adopted by the state of
Washington.
Where a mechanical ventilation system is installed, the
mechanical ventilation system shall be capable of supplying
ventilation air to each zone with the minimum outdoor air
quantities specified in Table 3-4.
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 3-4 estimated maximum occupancy values.
The outdoor air shall be ducted in a fully enclosed path
directly to every air handling unit in each zone not provided
with sufficient operable area for natural ventilation.
EXCEPTION:
Ducts may terminate within 12 inches of the intake to an HVAC unit provided they are physically
fastened so that the outside air duct is directed into the unit intake.
In all parking garages, other than open parking garages
as defined in IBC 406.3, used for storing or handling of
automobiles operating under their own power and on all loading
platforms in bus terminals, ventilation shall be provided at
1.5 cfm per square foot of gross floor area. The building
official may approve an alternate ventilation system designed
to exhaust a minimum fourteen thousand cfm for each operating
vehicle. Such system shall be based on the anticipated
instantaneous movement rate of vehicles but not less than 2.5
percent (or one vehicle) of the garage capacity. Automatic
carbon monoxide sensing systems may be submitted for approval.
In all buildings used for the repair of automobiles, each
repair stall shall be equipped with an exhaust extension duct,
extending to the outside of the building, which if over ten
feet in length, shall mechanically exhaust three hundred cfm. Connecting offices and waiting rooms shall be supplied with
conditioned air under positive pressure.
Combustion air requirements shall conform to the
requirements of Chapter 7 of the International Mechanical Code
(IMC).
Mechanical refrigerating equipment and rooms storing
refrigerants shall conform to the requirements of Chapter 11
of the IMC.
304.2 Alternate Systems: Alternate systems designed in
accordance with ASHRAE Standard 62.1.((1999))2004 shall be
permitted.
TABLE 3-1
Minimum Source Specific Ventilation Capacity
Requirements
| Bathrooms | Kitchens | |
| Intermittently operating | 50 cfm | 100 cfm |
| Continuous operation | 20 cfm | 25 cfm |
TABLE 3-2
Ventilation Rates For All Group R Occupancies four (4) stories and less*
Minimum and Maximum Ventilation Rates: Cubic Feet Per Minute (CFM)
| Floor Area, ft2 |
Bedrooms | |||||||||||||
| 2 or less | 3 | 4 | 5 | 6 | 7 | 8 | ||||||||
| Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | Min. | Max. | |
| <500 | 50 | 75 | 65 | 98 | 80 | 120 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 |
| 501-1000 | 55 | 83 | 70 | 105 | 85 | 128 | 100 | 150 | 115 | 173 | 130 | 195 | 145 | 218 |
| 1001-1500 | 60 | 90 | 75 | 113 | 90 | 135 | 105 | 158 | 120 | 180 | 135 | 203 | 150 | 225 |
| 1501-2000 | 65 | 98 | 80 | 120 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 | 155 | 233 |
| 2001-2500 | 70 | 105 | 85 | 128 | 100 | 150 | 115 | 173 | 130 | 195 | 145 | 218 | 160 | 240 |
| 2501-3000 | 75 | 113 | 90 | 135 | 105 | 158 | 120 | 180 | 135 | 203 | 150 | 225 | 165 | 248 |
| 3001-3500 | 80 | 120 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 | 155 | 233 | 170 | 255 |
| 3501-4000 | 85 | 128 | 100 | 150 | 115 | 173 | 130 | 195 | 145 | 218 | 160 | 240 | 175 | 263 |
| 4001-5000 | 95 | 143 | 110 | 165 | 125 | 188 | 140 | 210 | 155 | 233 | 170 | 255 | 185 | 278 |
| 5001-6000 | 105 | 158 | 120 | 180 | 135 | 203 | 150 | 225 | 165 | 248 | 180 | 270 | 195 | 293 |
| 6001-7000 | 115 | 173 | 130 | 195 | 145 | 218 | 160 | 240 | 175 | 263 | 190 | 285 | 205 | 308 |
| 7001-8000 | 125 | 188 | 140 | 210 | 155 | 233 | 170 | 255 | 185 | 278 | 200 | 300 | 215 | 323 |
| 8001-9000 | 135 | 203 | 150 | 225 | 165 | 248 | 180 | 270 | 195 | 293 | 210 | 315 | 225 | 338 |
| >9000 | 145 | 218 | 160 | 240 | 175 | 263 | 190 | 285 | 205 | 308 | 220 | 330 | 235 | 353 |
| *For residences that exceed 8 bedrooms, increase the minimum requirement listed for 8 bedrooms by an additional 15 CFM per bedroom. The maximum CFM is equal to 1.5 times the minimum. | ||||||||||||||
TABLE 3-3
Prescriptive Exhaust Duct Sizing
| Fan
Tested CFM @ 0.25 W.G. |
Minimum Flex Diameter |
Maximum Length Feet |
Minimum Smooth Diameter |
Maximum Length Feet |
Maximum Elbows1 |
| 50 | 4 inch | 25 | 4 inch | 70 | 3 |
| 50 | 5 inch | 90 | 5 inch | 100 | 3 |
| 50 | 6 inch | No Limit | 6 inch | No Limit | 3 |
| 80 | 4 inch2 | NA | 4 inch | 20 | 3 |
| 80 | 5 inch | 15 | 5 inch | 100 | 3 |
| 80 | 6 inch | 90 | 6 inch | No Limit | 3 |
| 100 | 5 inch2 | NA | 5 inch | 50 | 3 |
| 100 | 6 inch | 45 | 6 inch | No Limit | 3 |
| 125 | 6 inch | 15 | 6 inch | No Limit | 3 |
| 125 | 7 inch | 70 | 7 inch | No Limit | 3 |
| 1. | For each additional elbow subtract 10 feet from length. |
| 2. | Flex ducts of this diameter are not permitted with fans of this size. |
TABLE 3-4
Outdoor air requirements for ventilation1
Occupancies not subject to sections 302 and 303
| Application | Estimated Maximum2 Occupancy P/1000 ft2 or 100 m2 |
Outdoor Air Requirements cfm/person |
| Dry Cleaners, Laundries3 | ||
| Commercial laundry | 10 | 25 |
| Commercial dry cleaner | 30 | 30 |
| Storage, pick up | 30 | 35 |
| Coin-operated laundries | 20 | 15 |
| Coin-operated dry cleaner | 20 | 15 |
| Dwelling Units In Buildings Greater Than Four Stories or Attached to
I- Occupancy Facilities |
||
| Bedroom & living area24 | 15 | |
| Food and Beverage Service | ||
| Dining rooms | 70 | 20 |
| Cafeteria, fast food | 100 | 20 |
| Bars, cocktail lounges4 | 100 | 30 |
| Kitchens (cooking)23 | 20 | 15 |
| Garages, Repair, Service Stations | ||
| Enclosed parking garage5 | 1.50 cfm/ft.sq. | |
| Auto repair rooms | 1.50 cfm/ft.sq. | |
| Hotels, Motels, Resorts, Congregate Residences with More Than
Four Stories6 |
||
| Bedrooms | 30 cfm/room | |
| Living Rooms | 30 cfm/room | |
| Bath7 | 35 cfm/room | |
| Lobbies | 30 | 15 |
| Conference rooms | 50 | 20 |
| Assembly rooms | 120 | 15 |
| Gambling casinos4 | 120 | 30 |
| Offices | ||
| Office space9 | 7 | 20 |
| Reception area | 60 | 15 |
| Telecommunication centers and data entry areas |
60 | 20 |
| Conference rooms | 50 | 20 |
| Public Spaces | ||
| Corridors and utilities | 0.05 cfm/ft.sq. | |
| Public restroom, cfm/wc or urinal10 |
50 | |
| Lockers and dressing rooms | 0.50 cfm/ft.sq. | |
| Smoking lounge11 | 70 | 60 |
| Elevators12 | 1.0 cfm/ft.sq. | |
| Retail Stores, Sales Floors, and Show Room Floors | ||
| Basement and street | 30 | 0.30 cfm/ft.sq. |
| Upper floors | 20 | 0.20 cfm/ft.sq. |
| Storage rooms | 15 | 0.15 cfm/ft.sq. |
| Dressing rooms | 0.20 cfm/ft.sq. | |
| Malls and arcades | 20 | 0.20 cfm/ft.sq. |
| Shipping and receiving | 10 | 0.15 cfm/ft.sq. |
| Smoking lounge11 | 70 | 60 |
| Warehouses | 5 | 0.05 cfm/ft.sq. |
| Speciality Shops | ||
| Barber | 25 | 15 |
| Beauty | 25 | 25 |
| Reducing salons | 20 | 15 |
| Florists13 | 8 | 15 |
| Clothiers, furniture | 0.30 cfm/ft.sq. | |
| Hardware, drugs, fabric | 8 | 15 |
| Supermarkets | 8 | 15 |
| Pet shops | 1.00 cfm/ft.sq. | |
| Sports and Amusement14 | ||
| Spectator areas | 150 | 15 |
| Game rooms | 70 | 25 |
| Ice arenas (playing areas) | 0.50 cfm/ft.sq. | |
| Swimming Pools (pool and deck area)15 |
0.50 cfm/ft.sq. | |
| Playing floor (gymnasium) | 30 | 20 |
| Ballrooms and discos | 100 | 25 |
| Bowling alleys (seating areas) | 70 | 25 |
| Theaters16 | ||
| Ticket booths | 60 | 20 |
| Lobbies | 150 | 20 |
| Auditorium | 150 | 20 |
| Stages, studios | 70 | 15 |
| Transportation17 | ||
| Waiting rooms | 100 | 15 |
| Platforms | 100 | 15 |
| Vehicles | 150 | 15 |
| Workrooms | ||
| Meat processing18 | 10 | 15 |
| Photo studios | 10 | 15 |
| Darkrooms | 10 | 0.50 cfm/ft.sq. |
| Pharmacy | 20 | 15 |
| Bank vaults | 5 | 15 |
| Duplicating, printing19 | 0.50 cfm/ft.sq. | |
| INSTITUTIONAL FACILITIES | ||
| Education | ||
| Classroom | 50 | 15 |
| Laboratories20 | 30 | 20 |
| Training shop | 30 | 20 |
| Music rooms | 50 | 15 |
| Libraries | 20 | 15 |
| Locker rooms | 0.50 cfm/ft.sq. | |
| Corridors | 0.10 cfm/ft.sq. | |
| Auditoriums | 150 | 15 |
| Smoking lounges11 | 70 | 60 |
| Hospitals, Nursing and Convalescent Homes | ||
| Patient rooms21 | 10 | 25 |
| Medical procedure | 20 | 15 |
| Operating rooms | 20 | 30 |
| Recovery and ICU | 20 | 15 |
| Autopsy rooms22 | 0.50 cfm/ft.sq. | |
| Physical Therapy | 20 | 15 |
| Correctional Facilities | ||
| Cells | 20 | 20 |
| Dining halls | 100 | 15 |
| Guard station | 40 | 15 |
| 1. | Derived from ASHRAE Standard 62-1989. |
| 2. | Net occupiable space. |
| 3. | Dry-cleaning process may require more air. |
| 4. | Supplementary smoke-removal equipment may be required. |
| 5. | Distribution among people must consider worker location and concentration of running engine; stands where engines are run must incorporate systems for positive engine exhaust withdrawal. Contaminant sensors may be used to control ventilation. |
| 6. | Independent of room size. |
| 7. | Installed capacity for intermittent use. |
| 8. | See also food and beverage service, merchandising, barber and beauty shops, garages. |
| 9. | Some office equipment may require local exhaust. |
| 10. | Mechanical exhaust with no recirculation is recommended. |
| 11. | Normally supplied by transfer air, local mechanical exhaust; with no recirculation recommended. |
| 12. | Normally supplied by transfer air. |
| 13. | Ventilation to optimize plant growth may dictate requirements. |
| 14. | When internal combustion engines are operated for maintenance of playing surfaces, increased ventilation rates may be required. |
| 15. | Higher values may be required for humidity control. |
| 16. | Special ventilation will be needed to eliminate special stage effects. |
| 17. | Ventilation within vehicles may require special considerations. |
| 18. | Spaces maintained at low temperatures (-10°F. to+ 50°F.) are not covered by these requirements unless the occupancy is continuous. Ventilation from adjoining spaces is permissible. When the occupancy is intermittent, infiltration will normally exceed the ventilation requirements. |
| 19. | Installed equipment must incorporate positive exhaust and control of undesirable contaminants. |
| 20. | Special contamination control systems may be required for processes or functions including laboratory animal occupancy. |
| 21. | Special requirements or codes and pressure relationships may determine minimum ventilation rates and filter efficiency. Procedures generating contaminants may require higher rates. |
| 22. | Air shall not be recirculated into other spaces. |
| 23. | Makeup air for hood exhaust may require more ventilating air. |
| 24. | Occupant loading shall be based on the number of bedrooms as follows: first bedroom, two persons; each additional bedroom, one person. Where higher occupant loadings are known, they shall be used. |
TABLE 3-5
Prescriptive Integrated Forced Air Supply Duct Sizing
| Required Flow (CFM) Per Table 3-2 |
Minimum Smooth Duct Diameter |
Minimum Flexible Duct Diameter |
Maximum Length1 |
Maximum Number of Elbows2 |
| 50-80 | 6" | 7" | 20' | 3 |
| 80-125 | 7" | 8" | 20' | 3 |
| 115-175 | 8" | 10" | 20' | 3 |
| 170-240 | 9" | 11" | 20' | 3 |
| 1. | For lengths over 20 feet increase duct diameter 1 inch. |
| 2. | For elbows numbering more than 3 increase duct diameter 1 inch. |
| Supply Fan Tested CFM At 0.4" WG | ||
| Specified volume from Table 3-2 |
Minimum Smooth Duct Diameter |
Minimum Flexible Duct Diameter |
| 50-90 CFM | 4 inch | 5 inch |
| 90-150 CFM | 5 inch | 6 inch |
| 150-250 CFM | 6 inch | 7 inch |
| 250-400 CFM | 7 inch | 8 inch |
[Statutory Authority: RCW 19.27.190, 19.27.020, and chapters 19.27 and 34.05 RCW. 04-07-192, § 51-13-304, filed 3/24/04, effective 7/1/04. Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-304, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-304, filed 12/21/94, effective 6/30/95. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-304, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-304, filed 12/18/90, effective 7/1/91.]
501.1 General: The criteria of this chapter establishes
minimum radon resistive construction requirements for all
Group R Occupancies. These requirements are adopted pursuant
to the ventilation requirements of Section 7, of Chapter 2 of
the Session Laws of 1990.
501.2 Application: The requirements of this chapter
shall be adopted and enforced by all jurisdictions of the
state according to the following subsections:
501.2.1: All jurisdictions of the state shall comply
with section 502.
501.2.2: Clark, Ferry, Okanogan, Pend Oreille, Skamania,
Spokane, and Stevens counties shall also comply with section
503.
[Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-501, filed 12/21/94, effective 6/30/95; 91-01-102, § 51-13-501, filed 12/18/90, effective 7/1/91.]