Computational modelling of convective heat and moisture transfer at exterior building surfaces

The convective heat and moisture transfer (H&MT) at the windward wall of a 2D (infinitely long) square-shaped building is evaluated after a rain shower. The H&MT in the wall is modelled with a Heat, Air and Moisture model which is coupled with CFD to obtain detailed information on the convective transfer at the exterior surface. A significant spatial variation of the convective transfer coefficients (CTCs) is found over the wall, showing high drying rates near the roof top. The temporal variation of the CTCs is limited for this specific case. The coupled approach, using CFD, shows an added value compared to the use of constant (spatial and temporal) CTCs.