Definition:
ACH is an acronym for Air Changes per Hour and is a measurement of air infiltration. It is the total volume of air in a home that is turned over in one hour. Tightly constructed homes may have an ACH of 0.25 to 0.35 ACH.
ACH is an acronym for Air Changes per Hour and is a measurement of air infiltration. It is the total volume of air in a home that is turned over in one hour. Tightly constructed homes may have an ACH of 0.25 to 0.35 ACH.
A typically built new home may have an ACH of around 1.75 ACH. Older poorly weatherstripped and sealed homes may have higher than 2.5 ACH.

