Conjugate modelling of convective drying phenomena in porous building materials

Moisture storage and the associated heat and moisture transport in buildings have a large impact on the building envelope durability, the energy consumption in buildings and the indoor climate. Nowadays HAM (Heat, Air and Moisture transport) models are widely used to simulate and predict the effect of these transport phenomena in detail. Recently these HAM models are being coupled to CFD (Computational Fluid Dynamics) to study the moisture exchange between air and porous materials on a local scale (microclimates). The objective of this research is to develop such a model to study drying phenomena. In this paper the emphasis lies on the modelling of convective drying of porous building materials. An important aspect for the correct modelling of convective drying is the way the air boundary is implemented. A short literature review reveals that different modelling approaches can be used. This paper gives a short overview of the state of the art in conjugate heat and mass transport modelling for convective drying. In this review shortcomings of currently applied modelling approaches are highlighted. Finally the newly developed model is used to simulate the convective drying of a sample of ceramic brick. These simulations were then compared with measurements from literature. A good agreement was found.