Using CFD software for the evaluation of hygrothermal conditions at wall-window perimeters

This article evaluates the results of heat and moisture analyses for areas adjacent to a window, mounted in various ways to an external wall. The parameters for the window were assumed to be constant. The calculations were focussed on evaluating the effect of installing a window in a wall and the influence of the wall's construction on the quality of the microclimatic conditions in the contact zone of these two components. The following variables were analysed: a partition without insulation, a partition with thermal insulation, with additional expanding tape and with additional aerogel mat. Each the variable was additionally diversified with respect to the location of the window within the wall. The influence of the material used for the load-bearing wall layer was also analysed in the simulations. The variables were modelled using CFD (computational fluid dynamics) software. For all variables, the cumulative value of heat flux and linear thermal transmittances were calculated. Additionally, distributions of the 0 isotherm were determined and the f_Rsi temperature factors were calculated. These results have been thoroughly analysed to determine the most beneficial solution that provides optimal thermal insulation and reduced risk of mould. Our findings can help ensure the maintenance of an ideal microclimatic conditions and reduced energy wastage in the contact zone of windows with external walls. (paper)