Simulation of infiltration heat recovery.

Infiltration has traditionally been assumed to affect the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Results from detailed computational fluid dynamics simulations of five wall geometries over a range of infiltration rates show that heat transfer between the infiltrating air and walls can be substantial, reducing the impact of infiltration. The classical method for determining the infiltration energy load was found to over-predict the amount by as much as 95 percent and by at least 10 percent. However, in order to achieve significant heat recovery, flow paths which are unlikely in adventitious leakage are required.