The impact of courtyard roof shape on adjacent building natural ventilation and passive cooling

Abstract

Do all courtyard shapes perform equally? This study investigates how different roof styles impact natural ventilation and passive cooling in courtyard buildings. However, this analysis often overlooks a crucial factor: the interaction between the courtyard’s outdoor environment and the adjacent indoor spaces. Previous studies have largely concentrated on the external wind and thermal conditions, overlooking the exchange of air between the indoors and the courtyard. Addressing this research gap, the study investigates the impact of different roof styles on natural ventilation and temperature regulation within single-sided ventilated courtyard buildings. Employing Computational Fluid Dynamics (CFD) simulations validated against wind tunnel experiments, the research investigates common roof configurations such as flat, dome, butterfly, parapet, Chinese curved, mansard, open gable, gambrel, shed, and reverse shed. Our results indicate that roof geometry significantly affects airflow patterns, pressure distribution, and thermal conditions, demonstrating that it can play a crucial role in enhancing or impeding natural ventilation. Notably, the streamlined design of the dome roof enhanced natural ventilation, providing 80 % higher indoor wind speed than the traditional flat roof and lowering the average indoor temperatures by up to 2.1°C. Importantly, these ventilation patterns remain consistent across varying wind directions, confirming the robustness of the findings. In contrast, the parapet roof exhibits the least effective ventilation, with the highest average indoor temperature of 26.4°C and the lowest average wind speed. The analysis underscores that not all courtyard shapes perform equally. The dome and shed roofs are identified as better designs for enhancing natural ventilation and achieving more uniform temperature distributions across the indoor spaces.