The ventilated exhaust-air window provides an approach to combine the window system with exhaust air heat recovery. This new window can act as a heat exchange to recover the heat or cold of the exhaust-air to mitigate the heating or cooling load of the window. The zonal model is a reliable method to analyze the two-dimensional heat transfer of the ventilated exhaust-air window. However, the optimal subsection number of the zonal model for evaluating the thermal performance of the ventilated exhaust-air window has not been identified. In this study, a sensitivity analysis is carried out to estimate the effect of the subsection number on the simulation results of zonal model, and to identify the suitable and recommended subsection number for the numerical modeling of the ventilated exhaust-air window. The results indicated that reducing the subsection number in vertical direction will lead to a higher calculation deviation. In current case studies, the subsection number of 10 for the zonal modeling can zonal model can predict the thermal performance of the ventilated exhaust-air window with promising accuracy, while spending less computation time.
Keywords ventilated window, zonal model, sensitivity analysis, heat recovery, building energy efficiency