Calculation of heat and moisture transfer in exposed building components

Understanding the hygrothermal behaviour of exposed building components is a first step in avoiding damage or undue heat loss from constructions. Since experimental investigations are rather expensive and of limited transferability, there is an urgent need for reliable heat and moisture transfer calculations applicable in building practice. Such a calculation method, which is based on physical evidence concerning vapour and liquid transport and new experimental results, is presented and the required material and climatic data are described. To validate the model the calculation results for the moisture behaviour of a facade exposed to driving rain and solar radiation are compared to well documented measurements. As a consequence of this comparison it appears that the described model provides accurate results despite simplifications concerning the material properties. Copyright (C) 1996 Elsevier Science Ltd.