WAC 51-11C-61081. Section A108.1 — General

A108.1 General. Tables A108.1(1) and A108.1(2) list effective air change rates and heat capacities for heat loss due to infiltration for Single-Family Residential. The estimated seasonal average infiltration rate in air changes per hour (ACH) is given for standard air-leakage control (see Section R402.4 for air leakage requirements for Single-Family Residential). The effective air change rate shall be used in calculations for compliance under either the Component Performance or Systems Analysis approaches. Heat loss due to infiltration shall be computed using the following equation: Q infil = ACH eff * HCP Where: Q infil = Heat loss due to air infiltration. ACH eff = The effective air infiltration rate in Table A108.1(1) HCP = The Heat Capacity Density Product for the appropriate elevation or climate zone as given below. Q infil = ACH eff * HCP Where: Q infil = Heat loss due to air infiltration. ACH eff = The effective air infiltration rate in Table A108.1(1) HCP = The Heat Capacity Density Product for the appropriate elevation or climate zone as given below. Table A108.1(1) Assumed Effective Air Changes per Hour Air-Leakage Air Changes per Hour Control Package Natural Effective Standard 0.35 0.35 Air-Leakage Air Changes per Hour Control Package Natural Effective Standard 0.35 0.35 Table A108.1(2) Default Heat Capacity/Density Product for Air Zone Average Elevation Heat Capacity/Density 1 Mean Sea Level 0.0180 Btu/h • °F 2 2000 0.0168 Btu/h • °F 3 3000 0.0162 Btu/h • °F Zone Average Elevation Heat Capacity/Density 1 Mean Sea Level 0.0180 Btu/h • °F 2 2000 0.0168 Btu/h • °F 3 3000 0.0162 Btu/h • °F