This paper presents a simple method for estimating the total air change rate of a house with or without mechanical ventilation. The proposed method can be used to assess the effect of a mechanical ventilation system on total air change rates. It can also be included in existing simple computer programs for estimating heating requirements for houses.

A calculation procedure is also presented for sizing mechanical ventilation systems for houses. This procedure can be used to estimate the forced ventilation rate required to achieve the desired total air change rate.

Units: SI