Laserfiche WebLink
Washington State Amendments <br /> 403.8.��h/hole haiise ven�ilation requirements. Each 2. Outcioor air ducts for dedicated or central supply <br /> d�vellin�unit or sleeping unit shall be equipped with one of systems and e�aust ducts for heat or energy recovery <br /> the following four types of inechanical�vhole house systems shall be provided�vith a means for balancing <br /> ventilation systems: A system usin�exhaust fans(see the system to the required airflow via balance <br /> Section 403.8.6);a system integrated�vith forced-air dampers or other devices. <br /> systems(see Section 403.8.7); a system using supply fans ;. Outcioor air ducts, for dedi�ated or central systems <br /> (see Section 40�.8.8); or a heat or energy recovery shall be provided with motorized dampers. <br /> ventilation system(see Section 403.8.9). The�vhole hoi�se <br /> e�aust system is permitted to be one of the local exhaust Exceptions: <br /> systems required by Section 403.8.4 as long as the 1. Outdoor air ducts at heat or energy ventilation <br /> requirements of this section, in addition to the requirement systems are not required to have motorized <br /> of Section 403.$.5, are met. dampers. <br /> 2. Outdoor air ducts at continuous ventilation <br /> 403.8.5.1 Outcloor air. Outdoor air shall be distributed to systems are not required to have motorized <br /> each habitable space. dampers. <br /> Where outdaor air supply intakes are separated from 4. Oudoor air ducts in the conditioned space shall be <br /> exhaust vents by doors,means shall be provided to ensure insulated to a minimurn of R-4. In heat or energy <br /> airflow to all separated habitable spaces by installin� recovery ventilation systems,ducts upstream of ttie <br /> clisn-ibution d�icts, installed grilles,transoms, doars undercut hear exchan�er shail also be insulated to at least A-4. <br /> to a miniinum of 1/2-inch above the siu�face of the finish 5. All outdoor air ducts shall b�designed and installed <br /> floor covering, or other similar means�vhere permitted by to deliver at least the outdoor airflorv required by <br /> the International Buildin�Code. Section 403.8.5.1. The airflows required refer to the <br /> The mechanical system shall operate continuously to delivered airflorv of the system as installed and tested <br /> supply at least the volume of outdoor air required in Table usin�a flo�v hood,flow grid, or othec airflow <br /> 403.3 or Table 40�.8.1. measurement device. <br /> E�ception:Intermittently operating ventilation systems: Exception: The outdoor air duct for supp(y fan <br /> The whole house mechanical ventilation system is systems and heat or energy recovery systems may be <br /> permitted to operate intermittently where the system has prescriptively sized per Table 403.8.5.2 for dedicated <br /> controls that enable operation for not less than 25 percent outdoor air ducts upstream of the supply fan. Supply <br /> ' of each 4-hour segmerit and the ventilation rate prescribed fans shall have the capacity to provide the amo�mt of <br /> in Table 403.3 or Table 403.3.1 is multip(ied by the factor outdoor air required by Section 403.8.5.1 at 0.40 in. <br /> determined in accordance�vith Table 403.8.5.1. �v.g.as per HVI 916(April 1995). When <br /> Ti4�LE 403.�.5.1 prescriptively sized the systern shall be tested and <br /> ItdTERMITTENT 1�H�LE FiOUS� �II�CHANIC�lL balanced using a flo�v hood,flow-grid,or other <br /> V�RlTILATIO� �TE FACT�FtSa'� airflow measurement device. <br /> 6. Whole house ventilation controls for intennittent <br /> Run-Time operation shall allowconcuizent operation of the <br /> % in Each y5% 33% �0% 66% 75% 100% forced-air fan and the associated outdoor air <br /> 4-hour <br /> 3e ment motorized damper. <br /> Factor� �4 3 2 1.5 1.3 1.0 7• Whole house ventilation controls for continuous <br /> a. For ventilation system run-time values beriveen those operation shall be provided at the forced-air fan. <br /> given,the f�ctors are permitted to be determined by Exception: Engineered central ventilation systems <br /> interpolation. seiving dwelling units or sleeping tmits are not required <br /> b. Estrapolation beyond the table is prohibited, to have individual controls for each d�velling unit or <br /> 403.�.9.2 Whole house supply system �eneral sleeping unit when designed for continuous operation <br /> and approved by the code official. <br /> requirements. Whole house ventilation systems inte�rated <br /> with a forced-air system,systems using supply fans and TABLE 403.�.5.� <br /> systems using a heat or energy recovery ventilation system PFZESCR�PTIVE �UPPL.Y F/�IV DIJ���IZIRIG <br /> shall comply�vith the following. Supply Fan Tested CFM at 0.40"w.g. <br /> 1. Outdoor air louvers shall be adequately sized for the �pecified Minimum Minimum <br /> requirecl airflow and shall comply with Section 401.5. Volume from Smooth Duct Flexible Duct <br /> Outdoor air intake locations shall comply rvith Table 408.1 Diameter Diameter <br /> mechanical air intakes requirements of Section �0-90 cfm 4 inch 5 inch <br /> 403.83. 90-1�0 cfm �inch 6 inch <br />� I50-120 cfm 6 inch 7 inch <br />' 2�0-400 cf'm 7 inch 8 inch <br /> (Insert as Page 37c) <br /> Effective July 1, 2013 <br />