Prediction of mold risk in cavity walls combining a coupled CFD/HAM-model and a 2D hygrothermal model: the influence of the outer cavity layer on the inner cavity layer

Abstract

Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.Preventing mould risk in buildings is important to ensure a healthy environment for the people and to avoid material damage. A reliable prediction is especially important for ventilated cavity walls made of a moisture sensitive material such as wood. In this paper the influence of the outer cavity layer on the inner cavity layer has been analyzed. The cavity wall consists of a timber frame on the inside and a brick veneer on the outside separated by an air layer. For this hygrothermal evaluation of air cavities, coupled CFD/HAM-software and a commercial hygrothermal software package WUFI-2D® are used. First the coupled CFD/HAM-software is used to examine the heat and mass transfer coefficients at the surfaces between the air and the material layer and the applicability of the heat/mass-analogy. Afterwards, the effect of long-wave radiation in the cavity will be simulated with the coupled CFD/HAM-model. Finally the model developed in WUFI to simulate a ventilated cavity wall and the influence of different materials for the outer layer will be examined combining the coupled CFD/HAM-model and WUFI-2D.