WASHINGTON STATE REGISTER

WSR 07-01-095

PERMANENT RULES

BUILDING CODE COUNCIL

[ Filed December 19, 2006, 10:19 a.m. , effective July 1, 2007 ]

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Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 1, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.

Number of Sections Adopted at Request of a Nongovernmental Entity: New 0, Amended 1, Repealed 0.

Number of Sections Adopted on the Agency's Own Initiative: New 0, Amended 1, Repealed 0.

Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.

Number of Sections Adopted Using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 2, Repealed 0.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
Floor Area, ft²	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.

**TABLE 3-6**
**Prescriptive Supply Fan Duct Sizing**
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.]

AMENDATORY SECTION(Amending WSR 95-01-128, filed 12/21/94, effective 6/30/95)

WAC 51-13-501 Scope.

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.]

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.

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