IECC Climate Zone For Pennsylvania

Southeastern Pennsylvania sites in climate zone 4 according to the 2015 IECC, (International Energy Conservation Code). In climate zone 4, a blower door test resulting in 3 air changes per hour or less is the acceptable amount of times air should be changed in the home. The state of Pennsylvania however, amended that number to allow up to 5 air changes per hour. Refer to the map below to get a better understanding of climate zones across the United States.