Modelling of moisture and thermal transient behaviour of multilayer non-cavity walls

This paper describes a dynamic model for evaluating the transient thermal a nd moisture transfer behaviour in multi-layer noncavity wall constructions. Both heat and moisture transfer are simultaneously considered and their in teractions are modelled. An implicit finite-difference scheme has been util ized to solve the temperature and air moisture content distributions across the different layers of the wall system. The model mathematical formulatio ns pertaining to the method of solution are described together with interst itial condensation checking and node distribution criteria for transient mo isture transfer. By employing the developed model, both the moisture transp ort process and the material moisture content within the different layers o f a wall system can be evaluated at all possible material moisture conditio ns. The model is validated and proven to accurately predict the moisture be haviour of composite walls. (C) 1999 Elsevier Science Ltd. All rights reser ved.