WSR 09-17-137

PROPOSED RULES

BUILDING CODE COUNCIL


[ Filed August 19, 2009, 11:19 a.m. ]

     Original Notice.

     Preproposal statement of inquiry was filed as WSR 09-05-053.

     Title of Rule and Other Identifying Information: Amendment of chapter 51-13 WAC, Washington State Ventilation and Indoor Air Quality Code.

     Hearing Location(s): Holiday Inn Select Renton, One Grady Way South, Renton, WA, on September 29, 2009, at 10:00 a.m.; and at the Spokane City Council Chambers, West 808 Spokane Falls Boulevard, Spokane, WA, on October 5, 2009, at 9:00 a.m.

     Date of Intended Adoption: November 12, 2009.

     Submit Written Comments to: Peter DeVries, Council Chair, P.O. Box 42525, Olympia, WA 98504-2525, e-mail sbcc@commerce.wa.gov, fax (360) 586-9383, by October 5, 2009.

     Assistance for Persons with Disabilities: Contact Sue Mathers by September 15, 2009, TTY (360) 586-0772 or (360) 725-2966.

     Purpose of the Proposal and Its Anticipated Effects, Including Any Changes in Existing Rules: The proposed rules amend the Washington State Ventilation and Indoor Air Quality Code.

     Option 1: Repeal the Ventilation and Indoor Air Quality (VIAQ) Code, chapter 51-13 WAC. The provisions currently in the VIAQ will be relocated to the International Residential Code (IRC) (whole-house and source ventilation requirements for single-family and townhouses), the International Mechanical Code (IMC) (for other residential and nonresidential ventilation requirements), and the International Building Code (IBC) (for radon provisions for other than single-family and townhouses, and miscellaneous finishing requirements). See the CR-102 form change summaries for those codes for more information. This will help eliminate conflicts between codes and provide single-source reference material.

     Option 2: Retain the VIAQ Code with the following modifications. (These same modifications are shown in the relocated provisions noted above.)

     1. Section 301: The scoping of Chapter 3 is changed to apply to all residential construction. Ventilation for nonresidential occupancies shall comply with the IMC or IBC, as applicable.

     2. Section 302.1.1: Specifies that engineering calculations must be performed by a licensed engineer.

     3. Section 302.1.3: Allows ASHRAE 62.2 to be used as an alternate with approval of the building official.

     4. Section 302.3.1, Table 3-2, 302.3.1.1, 302.3.1.2 and Table 3-4: Values in Table 3-2 were updated to reflect a standard base case of continuous operation, consistent with ASHRAE 62.2. Maximum values are no longer found in the table. Table 3-4 and Section 302.3.1.2 provide data for calculating rates for ventilation systems operating intermittently.

     5. Section 302.3.3: The sone rating for whole house fans is reduced to 1.0.

     6. Section 303.4.1.5: The exception for outdoor air openings for exhaust only systems with forced air furnaces previous has been deleted.

     7. Section 303.4.2.1: This section was amended to reflect the methodology for calculating intermittent ventilation rates. In addition, the options for a manual damper or an automatic flow regulating device have been eliminated. The system must use a motorized damper and the rate verified through testing.

     8. Section 303.4.4.1: The requirements for heat recovery ventilation systems have been updated to reflect current practice.

     9. Section 304: Ventilation requirements for other than residential are relocated to the IMC.

     10. Section 501.1: Scoping for radon mitigation systems was clarified to explicitly refer IRC buildings to the IRC requirements for mitigation.

     Reasons Supporting Proposal: RCW 19.27.190 and 19.27.020.

     Statutory Authority for Adoption: RCW 19.27.190 and 19.27.020.

     Statute Being Implemented: Chapters 19.27 and 34.05 RCW.

     Rule is not necessitated by federal law, federal or state court decision.

     Agency Comments or Recommendations, if any, as to Statutory Language, Implementation, Enforcement, and Fiscal Matters: The council is seeking comments on the issues proposed in the rules shown below.

     Name of Proponent: Washington state building code council, governmental.

     Name of Agency Personnel Responsible for Drafting and Implementation: Krista Braaksma, P.O. Box 42525, Olympia, WA 98504-2525, (360) 725-2964; and Enforcement: Local jurisdictions.

     No small business economic impact statement has been prepared under chapter 19.85 RCW. During review of the proposed changes, the technical advisory group and the economic and regulator assessment committee did not identify any items with potential disproportionate cost impact to small business.

     A cost-benefit analysis is not required under RCW 34.05.328. The state building code council is not listed in this section as one of the agencies required to comply with this statute.

August 1, 2009

Peter D. DeVries

Council Chair

OTS-2557.1

OPTION 1
REPEALER
     The following chapter of the Washington Administrative Code is repealed:
WAC 51-13-100 Chapter 1 -- Administration and enforcement.
WAC 51-13-101 Scope and general requirements.
WAC 51-13-102 Alternate systems and materials method of design, construction and installation.
WAC 51-13-103 Plans and specifications.
WAC 51-13-104 Enforcement and inspections.
WAC 51-13-105 Validity.
WAC 51-13-106 Conflicts with other codes.
WAC 51-13-107 Violations.
WAC 51-13-108 Liability.
WAC 51-13-200 Definitions.
WAC 51-13-201 General.
WAC 51-13-202 Definitions.
WAC 51-13-300 Chapter 3 -- Ventilation systems.
WAC 51-13-301 Compliance with this chapter.
WAC 51-13-302 Mechanical ventilation criteria using performance or design methods for Group R Occupancies four stories and less.
WAC 51-13-303 Mechanical ventilation criteria using prescriptive methods for Group R Occupancies four stories and less.
WAC 51-13-304 Mechanical ventilation criteria and minimum ventilation performance for all other occupancies not covered in sections 302 and 303.
WAC 51-13-400 Chapter 4 -- Indoor air quality.
WAC 51-13-401 Pollutant source control.
WAC 51-13-402 Solid fuel burning appliances and fireplaces.
WAC 51-13-500 Chapter 5 -- Radon resistive construction standards.
WAC 51-13-501 Scope.
WAC 51-13-502 Statewide radon requirements.
WAC 51-13-503 Radon prescriptive requirements.

OTS-2558.1

OPTION 2
AMENDATORY SECTION(Amending WSR 01-02-099, filed 1/3/01, effective 7/1/01)

WAC 51-13-301   Compliance with this chapter.  


     301.1 General: The criteria of this chapter establish the minimum design conditions ((upon which the minimum)) for ventilation systems ((are to be based)) for ((all occupancies.)) Group R Occupancies ((four (4) stories and less)) as defined by the Washington State Building Code. All other occupancies shall comply with ((either Section 302 or 303. Section 304 applies to all other occupancies)) the International Building Code and International Mechanical Code.


     301.2 Compliance options: Group R Occupancies shall comply with either Section 302 or 303.


     301.3 Testing: At the discretion of the building official, flow testing may be required to verify that the mechanical system(s) satisfies the requirements of this section. Flow testing may be performed using flow hoods measuring at the intake or exhaust points of the system, in-line pitot tube, or pitot-traverse type measurement systems in the duct, short term tracer gas measurements, or other means approved by the building official.

[Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-301, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-301, filed 12/18/90, effective 7/1/91.]


AMENDATORY SECTION(Amending WSR 04-07-192, filed 3/24/04, effective 7/1/04)

WAC 51-13-302   Mechanical ventilation criteria using performance or design methods for Group R Occupancies ((four stories and less)).  


     302.1 Applicability: Group R Occupancies ((four (4) stories and less)) as defined by the Washington State Building Code shall comply with either this section or Section 303.


     302.1.1 Compliance by Calculations or Testing: Compliance with this section shall be demonstrated through engineering calculation by an engineer licensed to practice in the state of Washington or performance testing. Documentation of calculations or performance test results shall be submitted to the building official. Performance testing shall be conducted in accordance with recognized test methods.


     302.1.2 Minimum Ventilation Performance: Each dwelling unit or guest room shall be equipped with source specific and whole house ventilation systems designed and installed to satisfy the ventilation requirements of this section.


     All public corridors shall meet the ventilation requirements in section 1203 of the International Building Code.


     302.1.3 Alternate Systems: When approved by the code official, systems designed and installed in accordance with ASHRAE Standard 62.2-2007 shall be permitted.


     302.2 Source Specific Ventilation Requirements.


     302.2.1 Source Specific Ventilation: Source specific exhaust ventilation is required in each kitchen, bathroom, water closet, laundry room, indoor swimming pool, spa, and other rooms where ((excess)) water vapor or cooking odor is produced.


     The minimum source specific ventilation effective exhaust capacity shall be not less than levels specified in Table 3-1.


     302.2.2 Source Specific Ventilation Controls: Source specific ventilation systems shall be controlled by manual switches, dehumidistats, timers, or other approved means. Source specific ventilation system controls shall be readily accessible.


     302.2.3 Source Specific Ventilation Ducts: Source specific ventilation ducts shall terminate outside the building. Exhaust ducts in systems which are designed to operate intermittently shall be equipped with back-draft dampers. All exhaust ducts in unconditioned spaces shall be insulated to a minimum of R-4. Terminal elements shall have at least the equivalent net free area of the duct work. Terminal elements for exhaust fan duct systems shall be screened or otherwise protected from entry by leaves or other material.


     302.3 Requirements for Whole House Ventilation Systems.


     302.3.1 Whole House Ventilation Systems: Each dwelling unit shall be equipped with a whole house ventilation system which shall be capable of providing the volume of outdoor air specified in Table 3-2 under normal operating conditions.


((EXCEPTION: Maximum flow rates listed in Table 3-2 do not apply to heat recovery ventilation systems.))


     302.3.1.1 Continuously Operating Exhaust Ventilation Systems: Continuously operating exhaust ventilation systems shall provide the minimum flow rates specified in Table 3-2.


     302.3.1.2 Intermittently Operating Ventilation Systems: The delivered ventilation rate for intermittently operating ventilation systems shall be the combination of its delivered capacity (Table 3-2), its ventilation effectiveness (Table 3-4), and its daily fractional operation time (Table 3-4).


Qf = Qr/(&egr;f)
Where:
Qf = fan flow rate
Qr = ventilation air requirement (from Table 3-2
&egr; = ventilation effectiveness (from Table 3-4)
f = fractional operation time

     302.3.2 Whole House Ventilation System Controls: All ventilation system controls shall be readily accessible. Controls for whole house ventilation systems shall be capable of operating the ventilation system without energizing other energy-consuming appliances.


     Intermittently operated whole house ventilation systems shall be constructed to have the capability for continuous operation, and shall have a manual control and an automatic control, such as a clock timer. At the time of final inspection, the automatic control timer shall be set to operate the whole house fan for at least eight hours a day. A label shall be affixed to the control that reads "Whole House Ventilation (see operating instructions)."


     302.3.3 Fan Noise: Whole house fans located four feet or less from the interior grille shall have a sone rating of ((1.5)) 1.0 or less measured at 0.1 inches water gauge. Manufacturer's noise ratings shall be determined as per HVI 915 (October 1995). Remotely mounted fans shall be acoustically isolated from the structural elements of the building and from attached duct work using insulated flexible duct or other approved material.


EXCEPTION: Whole house ventilation systems which are integrated with forced-air heating systems or heat-recovery ventilation systems are exempt from the sone rating requirements of this section.

     302.3.4 Whole House Ventilation Ducts: All ducts shall terminate outside the building. Exhaust ducts in systems which are designed to operate intermittently shall be equipped with back-draft dampers. All exhaust ducts in unconditioned spaces shall be insulated to a minimum of R-4. All supply ducts in the conditioned space shall be insulated to a minimum of R-4.


     302.3.5 Outdoor Air.


     302.3.5.1 Outdoor Air Supply: A mechanical system shall supply outdoor air as required in Section 302.3.1. The mechanical system may consist of exhaust fans, supply fans, or both.


     302.3.5.2 Outdoor Air Inlets: Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:


a)     Closer than ten feet from an appliance vent outlet, unless such vent outlet is three feet above the outdoor air inlet.


b)     Where it will pick up objectionable odors, fumes, or flammable vapors.


c)     A hazardous or unsanitary location.


d)     A room or space having any fuel-burning appliances therein.


e)     Closer than ten feet from a vent opening of a plumbing drainage system unless the vent opening is at least three feet above the air inlet.


f)     Attic, crawl spaces, garages.


     302.3.5.3 Outdoor Air Distribution: Outdoor air shall be distributed to each habitable room by means such as individual inlets, separate duct systems, or a forced-air system. Where outdoor air supplies are separated from exhaust points by doors, provisions shall be made to ensure air flow by installation of distribution ducts, undercutting doors, installation of grilles, transoms, or similar means where permitted by the International Building Code. Doors shall be undercut to a minimum of one-half inch above the surface of the finish floor covering.


     302.3.5.4 Doors and operable lites in windows are deemed not to meet the outdoor air supply intake requirements.


     302.3.5.5 Individual Room Outdoor Air Inlets: Where provided, individual room outdoor air inlets shall:

     a) Have controllable and secure openings;

     b) Be sleeved or otherwise designed so as not to compromise the thermal properties of the wall or window in which they are placed.


     302.3.5.6 Ventilation Integrated with Forced-Air Systems: Where outdoor air is provided by a forced-air system, the outdoor air connection to the return air stream shall be located upstream of the forced-air system blower and shall not be connected directly into a furnace cabinet to prevent thermal shock to the heat exchanger.

[Statutory Authority: RCW 19.27.190, 19.27.020, and chapters 19.27 and 34.05 RCW. 04-07-192, § 51-13-302, filed 3/24/04, effective 7/1/04. Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-302, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190. 95-01-128, § 51-13-302, filed 12/21/94, effective 6/30/95. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-302, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-302, filed 12/18/90, effective 7/1/91.]


AMENDATORY SECTION(Amending WSR 04-07-192, filed 3/24/04, effective 7/1/04)

WAC 51-13-303   Mechanical ventilation criteria using prescriptive methods for Group R Occupancies ((four stories and less)).  


     303.1 Applicability: Group R Occupancies 4 stories or less shall comply with this section or Section 302. This section establishes minimum prescriptive design requirements for intermittently operated systems. Continuously operated systems shall comply with Section 302. A system which meets the requirements of this section shall be deemed to satisfy the requirements of this chapter.


     303.2 Minimum Ventilation Performance: Each dwelling unit or guest room shall be equipped with source specific and whole house ventilation systems designed and installed to satisfy the ventilation requirements of this section. All public corridors shall meet the ventilation requirements in Section 1203 of the International Building Code.


     303.3 Source Specific Exhaust Ventilation Requirements.


     303.3.1 Source Specific Ventilation: Source specific exhaust ventilation is required in each kitchen, bathroom, water closet, laundry room, indoor swimming pool, spa, and other rooms where excess water vapor or cooking odor is produced. The minimum source specific ventilation effective exhaust capacity shall be not less than levels specified in Table 3-1.


     303.3.2 Source Specific Exhaust Fans: Exhaust fans providing source specific ventilation shall have a minimum fan flow rating not less than 50 cfm at 0.25 inches water gauge for bathrooms, laundries, or similar rooms and 100 cfm at 0.25 inches water gauge for kitchens. Manufacturers' fan flow ratings shall be determined as per HVI 916 (April 1995) or AMCA 210.


EXCEPTION: Where a range hood or down draft exhaust fan is used to satisfy the source specific ventilation requirements for kitchens, the range hood or down draft exhaust shall not be less than 100 cfm at 0.10 inches water gauge.

     303.3.3 Source Specific Ventilation Controls: Source specific ventilation systems shall be controlled by manual switches, dehumidistats, timers, or other approved means. Source specific ventilation system controls shall be readily accessible.


     303.3.4 Source Specific Ventilation Ducts: Source specific ventilation ducts shall terminate outside the building. Exhaust ducts shall be equipped with back-draft dampers. All exhaust ducts in unconditioned spaces shall be insulated to a minimum of R-4. Terminal elements shall have at least the equivalent net free area of the duct work. Terminal elements for exhaust fan duct systems shall be screened or otherwise protected from entry by leaves or other material.


     303.4 Prescriptive Whole House Ventilation Systems: Whole house ventilation shall be provided by a system that meets the requirements of either Section 303.3.1, 303.3.2, 303.3.3, or 303.3.4. A system which meets all of the requirements of one of these sections shall be deemed to satisfy the requirements for a whole house ventilation system.


     303.4.1 Intermittent Whole House Ventilation Using Exhaust Fans: This section establishes minimum prescriptive requirements for intermittent whole house ventilation systems using exhaust fans. A system which meets all the requirements of this section shall be deemed to satisfy the requirements for a whole house ventilation system.


     303.4.1.1 Whole House Ventilation Fans: Exhaust fans providing whole house ventilation shall have a flow rating at 0.25 inches water gauge as specified in Table 3-2. Manufacturers' fan flow ratings shall be determined according to HVI 916 (April 1995) or AMCA 210.


     303.4.1.2 Fan Noise: Whole house fans located four feet or less from the interior grille shall have a sone rating of 1.5 or less measured at 0.1 inches water gauge. Manufacturer's noise ratings shall be determined as per HVI 915 (October 1995). Remotely mounted fans shall be acoustically isolated from the structural elements of the building and from attached duct work using insulated flexible duct or other approved material.


     303.4.1.3 Fan Controls: The whole house ventilation fan shall be controlled by a 24-hour clock timer with the capability of continuous operation, manual and automatic control. The 24-hour timer shall be readily accessible. The 24-hour timer shall be capable of operating the whole house ventilation fan without energizing other energy-consuming appliances. At the time of final inspection, the automatic control timer shall be set to operate the whole house fan for at least eight hours a day. A label shall be affixed to the control that reads "Whole House Ventilation (see operating instructions)."


     303.4.1.4 Exhaust Ducts: All exhaust ducts shall terminate outside the building. Exhaust ducts shall be equipped with back-draft dampers. All exhaust ducts in unconditioned spaces shall be insulated to a minimum of R-4.


     303.4.1.5 Outdoor Air Inlets: Outdoor air shall be distributed to each habitable room by individual outdoor air inlets. Where outdoor air supplies are separated from exhaust points by doors, provisions shall be made to ensure air flow by installation of distribution ducts, undercutting doors, installation of grilles, transoms, or similar means where permitted by the International Building Code. Doors shall be undercut to a minimum of one-half inch above the surface of the finish floor covering.


     Individual room outdoor air inlets shall:

     a. Have controllable and secure openings;

     b. Be sleeved or otherwise designed so as not to compromise the thermal properties of the wall or window in which they are placed;

     c. Provide not less than four square inches of net free area of opening for each habitable space. Any inlet or combination of inlets which provide 10 cfm at 10 Pascals as determined by the Home Ventilating Institute Air Flow Test Standard (HVI 901 (November 1996)) are deemed equivalent to four square inches net free area.


     Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:

     a. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

     b. Where it will pick up objectionable odors, fumes or flammable vapors.

     c. A hazardous or unsanitary location.

     d. A room or space having any fuel-burning appliances therein.

     e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

     f. Attic, crawl spaces, or garages.


((EXCEPTION: Exhaust only ventilation systems do not require outdoor air inlets if the home has a ducted forced air heating system that communicates with all habitable rooms and the interior doors are undercut to a minimum of one-half inch above the surface of the finish floor covering.))

     303.4.2 Prescriptive Requirements for Intermittent Whole House Ventilation Integrated with a Forced-Air System: This section establishes minimum prescriptive requirements for intermittent whole house ventilation systems integrated with forced-air ventilation systems. A system which meets all the requirements of this section shall be deemed to satisfy the requirements for a whole house ventilation system.


     303.4.2.1 Integrated Whole House Ventilation Systems: Integrated Whole House Ventilation Systems shall provide outdoor air at the rates ((specified in Table 3-2)) calculated using Section 302.3.1. Integrated Forced-Air Ventilation Systems shall distribute outdoor air to each habitable room through the forced-air system ducts. Integrated Forced-Air Ventilation Systems shall have an outdoor air inlet duct connecting a terminal element on the outside of the building to the return air plenum of the forced-air system, at a point within four (4) feet upstream of the air handler. The outdoor air inlet duct connection to the return air stream shall be located upstream of the forced-air system blower and shall not be connected directly into a furnace cabinet to prevent thermal shock to the heat exchanger. ((The outdoor air inlet duct shall be prescriptively sized in accordance with Table 3-5.)) The system will be equipped with ((one of the following:

     1.)) a motorized damper connected to the automatic ventilation control as specified in Section 303.3.2.2((; or

     2. A damper installed and set to meet minimum flow rates as specified in Table 3-2, by either field testing or following manufacturer's installation instructions based on site conditions; or

     3. An automatic flow regulated device with field measured or field calculated minimum negative pressure of 0.07 inches water gauge at the point where the outside air duct is connected to the return air plenum)). The required flow rate shall be verified by field testing with a flow hood or a flow measuring station.


     303.4.2.2 Ventilation Controls: The whole house ventilation system shall be controlled by a 24-hour clock timer with the capability of continuous operation, manual and automatic control. This control will control the forced air system blower and ((if applicable)) the automatic damper. The 24-hour timer shall be readily accessible. The 24-hour timer shall be capable of operating the whole house ventilation system without energizing other energy-consuming appliances. At the time of final inspection, the automatic control timer shall be set to operate the whole house system for at least eight hours a day. A label shall be affixed to the control that reads "Whole House Ventilation (see operating instructions)."


     303.4.2.3 Ventilation Duct Insulation: All supply ducts in the conditioned space shall be insulated to a minimum of R-4.


     303.4.2.4 Outdoor Air Inlets: Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:

     a. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

     b. Where it will pick up objectionable odors, fumes or flammable vapors.

     c. A hazardous or unsanitary location.

     d. A room or space having any fuel-burning appliances therein.

     e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

     f. Attic, crawl spaces, or garages.


     303.4.3 Prescriptive Requirements for Intermittent Whole House Ventilation Using a Supply Fan: This section establishes minimum prescriptive requirements for intermittent whole house ventilation systems using an inline supply fan. A system which meets all the requirements of this section shall be deemed to satisfy the requirements for a whole house ventilation system.


     303.4.3.1 Outdoor Air: Supply Fan Ventilation Systems shall distribute outdoor air to each habitable room through the forced-air system ducts or through dedicated ducts to each habitable room. Supply fans shall have the capacity to provide the amount of outdoor air specified in Table 3-2 at 0.4 inches water gauge as per HVI 916 (April 1995). The outdoor air must be filtered before it is delivered to habitable rooms. The filter may be located at the intake device, inline with the fan, or, in the case of a connection to the return plenum of the airhandler, using the furnace filter. An outdoor air inlet shall be connected to either the supply or return air stream.


     303.4.3.2 Ducts: An outdoor air inlet duct connection to the supply air stream shall be located downstream of the forced-air system blower. An outdoor air inlet duct connection to the return air stream shall be located at least four feet upstream of the forced-air system blower and its filter. Neither type of duct shall be connected directly into a furnace cabinet to prevent thermal shock to the heat exchanger. The outdoor air inlet duct shall be prescriptively sized in accordance with Table 3-6. The terminal element on the outside of the building shall be sized two inches in diameter larger than the outdoor air inlet duct.


     303.4.3.3 Dampers: The system shall be equipped with a back-draft damper and one of the following:

     1. A calibrated manual volume damper installed and set to meet the measured flow rates specified in Table 3-2 by field testing with a pressure gauge and/or following manufacturer's installation instructions, or

     2. A manual volume damper installed and set to meet the measured flow rates specified in Table 3-2 by field testing with a flow hood or a flow measuring station; or

     3. An automatic flow-regulating device sized to the specified flow rates in Table 3-2 which provides constant flow over a pressure range of 0.2 to 0.6 inches water gauge.


     303.4.3.4 Ventilation Controls: The whole house ventilation system shall be controlled by a 24 hour clock timer with the capability of continuous operation, manual and automatic control. This control will control the inline supply fan. The 24-hour timer shall be readily accessible. The 24 hour timer shall be capable of operating the whole house ventilation system without energizing other energy-consuming appliances. At the time of final inspection, the automatic control timer shall be set to operate the whole house system for at least eight hours a day. A label shall be affixed to the control that reads "Whole House Ventilation (see operating instructions)."


     303.4.3.5 Ventilation Duct Insulation: All supply ducts in the conditioned space shall be insulated to a minimum of R-4.


     303.4.3.6 Outdoor Air Inlets: Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:

     a. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

     b. Where it will pick up objectionable odors, fumes or flammable vapors.

     c. A hazardous or unsanitary location.

     d. A room or space having any fuel-burning appliances therein.

     e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

     f. Attic, crawl spaces, or garages.


     303.4.4 Prescriptive Requirements for Intermittent Whole House Ventilation Using a Heat Recovery Ventilation System: This section establishes minimum prescriptive requirements for intermittent whole house ventilation using a heat recovery ventilation system.


     303.4.4.1 Heat Recovery Ventilation Systems: All duct work in heat recovery ventilation systems shall be ((not less than six inch diameter. Balancing dampers shall be installed on the inlet and exhaust side. Flow measurement grids shall be installed on the supply and return. System minimum flow rating shall be not less than that specified in Table 3-2. Maximum flow rates in Table 3-2 do not apply to heat recovery ventilation systems)) sized and installed per the manufacturer's instructions. System minimum flow rating shall be not less than that specified in Table 3-2. Heat recovery ventilation systems shall have a filter on the upstream side of the heat exchanger in both the intake and exhaust airstreams with a Minimum Efficiency Ratings Value (MERV) of 6.


     303.4.4.2 Ventilation Controls: The whole house ventilation system shall be controlled by a 24 hour clock timer with the capability of continuous operation, manual and automatic control. This control will control the inline supply fan. The 24-hour timer shall be readily accessible. The 24-hour timer shall be capable of operating the whole house ventilation system without energizing other energy-consuming appliances. At the time of final inspection, the automatic control timer shall be set to operate the whole house system for at least eight hours a day. A label shall be affixed to the control that reads "Whole House Ventilation (see operating instructions)."


     303.4.4.3 Ventilation Duct Insulation: All supply ducts in the conditioned space installed upstream of the heat exchanger shall be insulated to a minimum of R-4.


     303.4.4.4 Outdoor Air Inlets: Inlets shall be screened or otherwise protected from entry by leaves or other material. Outdoor air inlets shall be located so as not to take air from the following areas:

     a. Closer than 10 feet from an appliance vent outlet, unless such vent outlet is 3 feet above the outdoor air inlet.

     b. Where it will pick up objectionable odors, fumes or flammable vapors.

     c. A hazardous or unsanitary location.

     d. A room or space having any fuel-burning appliances therein.

     e. Closer than 10 feet from a vent opening of a plumbing drainage system unless the vent opening is at least 3 feet above the air inlet.

     f. Attic, crawl spaces, or garages.

[Statutory Authority: RCW 19.27.190, 19.27.020, and chapters 19.27 and 34.05 RCW. 04-07-192, § 51-13-303, filed 3/24/04, effective 7/1/04. Statutory Authority: RCW 19.27.190, 19.27.020. 01-02-099, § 51-13-303, filed 1/3/01, effective 7/1/01. Statutory Authority: RCW 19.27.190(2) and 1992 c 132. 93-02-056, § 51-13-303, filed 1/6/93, effective 7/1/93. Statutory Authority: RCW 19.27.190. 91-01-102, § 51-13-303, filed 12/18/90, effective 7/1/91.]


AMENDATORY SECTION(Amending WSR 07-01-095, filed 12/19/06, effective 7/1/07)

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 62.1.2004 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))) (Continuously operating systems)

((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.))

Bedrooms
Floor Area, ft2 0-1 2-3 4-5 6-7 >7
<1500 30 45 60 75 90
1501-3000 45 60 75 90 105
3001-4500 60 75 90 105 120
4501-6000 75 90 105 120 135
6001-7500 90 105 120 135 150
>7500 105 120 135 150 165

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.))

Ventilation Effectiveness for Intermittent Fans

Daily Fractional Operation Time, f Ventilation Effectiveness, &egr;
f ≤ 35% 0.33
35% f < 60% 0.50
60% ≤ f < 80% 0.75
80% ≤ f 1.0

For systems designed to operate at least once every three hours, ventilation effectiveness can be 1.0.

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. 07-01-095, § 51-13-304, filed 12/19/06, effective 7/1/07; 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 07-01-095, filed 12/19/06, effective 7/1/07)

WAC 51-13-501   Scope.  


     501.1 General: The criteria of this chapter establishes minimum radon resistive construction requirements for all Group R Occupancies except buildings complying with the International Residential Code. 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 and 19.27.020 and Chapters 19.27 and 34.05 RCW. 07-01-095, § 51-13-501, filed 12/19/06, effective 7/1/07. 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.]

© Washington State Code Reviser's Office