The Impact of Double-Skin Facade Configurations on Wind-Driven Ventilation in Tall Office Buildings

Abstract

Natural ventilation has proven to be an effective passive strategy in improving energy efficiency while providing healthy environments. However, such a strategy has not been commonly adopted in tall office buildings due to the high wind pressure that causes excessive air velocities and occupant discomfort at upper floors. Double-skin facades (DSFs) can provide an opportunity to facilitate natural ventilation in tall office buildings, as they can regulate the direct impact of wind pressure, creating a buffer. This study investigates the impact of DSF configurations on wind-driven ventilation at upper floors of tall office buildings. Computational fluid dynamics (CFD) analysis was performed to simulate indoor airflow at the top 10 floors of a 40-story tall office building under isothermal conditions and assess the performance of 16 DSF configurations with respect to opening size, the number of outer skin openings per floor, cavity depth, and cavity segmentation. The results indicate that the size of outer skin openings is the most influential parameter on indoor airflow, while the cavity depth and segmentation do not significantly affect it. However, the size of inner skin openings and the number of outer skin openings are more important factors in enhancing airflow distribution and regulating the concentration of high air velocity near the windows. This study aims to develop a performance-based DSF design guideline through CFD simulations of indoor airflow behavior in tall office buildings with DSFs.