Evaluation of airflow pattern in wind-driven naturally ventilated atrium buildings: measurement and simulation

This article presents a study of airflow pattern inside a five-story wind-driven naturally ventilated atrium building. Firstly, field measurement conducted in the atrium building reveals the existence of reversed flows from the atrium to windows, which could cause air cross-contamination between floors during the period of an infectious disease outbreak. The computational fluid dynamics technique was then employed to further investigate the airflow pattern inside the building, under different wind directions and opening ratios. It is found that the airflow pattern inside a wind-driven naturally ventilated atrium building is very sensitive to the oncoming wind direction. Under parallel and perpendicular incident wind directions, the existence of adversely reversed flows in a certain floor and the re-entry of used air from an upper floor into its adjacent lower floors through the atrium results in the decrease of indoor air quality and the effective air exchange through windows. Nevertheless, the building has good natural ventilation performance under oblique incident wind direction, although the expected role of the atrium is still not fully achieved. In addition, the improvement of airflow pattern inside wind-driven naturally ventilated buildings cannot be achieved by simply modifying the opening ratios. Practical application: Considering the indoor airflow pattern could substantially influence the elimination efficiency of pollutants and overheated air, this study is expected to help designers and engineers who are considering the use of an atrium at the design stage to have a better understanding of the airflow pattern inside a wind-driven naturally ventilated atrium building.