Transient analysis of the thermal and moisture physical behaviour of building constructions

For the transient analysis of the thermal and moisture conditions in multilayer constructions a numerical algorithm and a computer program based on the Crank-Nicholson method and quasi linearisation are formulated. Temperature and moisture content are used as transport potentials. In energy balance equations and conditions, convention and accumulation of moisture, the diffusion flow of water vapour, the capillary and surface diffusion flow of liquid water and the viscous flow of humid air and water are considered. The boundary layer and interfacial balance equations are derived. The accuracy of the numerical algorithm is compared with an analytical solution for thermally semi-infinite body. The validity of the simulation method is verified by two experiments.