Building exterior envelope.
CFR · 2024-01-01 · US · Title 10
516.1 516.2 516.2.1 When the HVAC system is switched “on,” no infiltration shall be assumed. When the HVAC system is switched “off,” the infiltration rate for buildings with or without operable windows shall be assumed to be 0.038 cfm/ft 516.3 516.4 516.5
official document · source cfr-2024 · id 10:§ 434.516