Effect of exfiltration on the hygrothermal behaviour of a residential wall assembly:Results from calculations and computer simulations

The hygrothermal behaviour of timber frame wall is analysed using a steady-state calculation method and a two-dimensional heat, air and moisture transport computer model. The conditions leading to exfiltration of warm and humid indoor air are examined. The physical quantities calculated include the amount of moisture accumulated in the wall cavity during the heating season and the heat loss across the wall. Several interesting correlations emerge. These correlations show the advantage of using the analytical methods in deriving design guidelines for building components. The results from The analysis are used to identify and quantify various parameters that govern the performance of air barrier systems