Computational Analysis of Cross Ventilation for Spaces with Operable Transom Windows in Hot and Humid Climate

Natural ventilation is an important free cooling strategy for residential building in hot or warm climates by providing fresh air and increasing room air flow without using mechanical cooling/ventilation systems when the exterior condition is suitable. While single-sided natural ventilation has been widely studied, the applications of double-sided natural ventilation (cross ventilation) require more attentions especially in hot climate and might provide some extra potential for achieving net-zero residential buildings. This study aims to analyze double-sided (window-side and door-sided) nature ventilation in an apartment space with one door and one window on opposite sides by using 3D steady Computational Fluid Dynamics (CFD) simulations with the SST k-ω turbulence model. Five different transom windows configurations commonly used in Taiwan’s residential buildings were analyzed and compared. Parametric study regarding size and position were conducted to provide design recommendations. Furthermore, occupants’ thermal comfort were analyzed using simplified assumptions to determine the hour numbers that the spaces were able to use free cooling and compared to single-sided design. The results can be used as references for future transom window design