Quantifying the influences of wind conditions on multi-storey solar chimney

Previous studies on multi-storey solar chimneys usually overlooked the external wind influence. This study quantifies the external wind effects on the ventilation performance of multi-storey solar chimney. Simulations analyze the performance of solar chimneys under varying wind speeds and directions, comparing the ventilation efficiency across buildings with different floor counts, and revealing the change pattern of wind influence with the number of building floors. Results showed that wind direction and velocity are critical to multi-storey solar chimney performance. On the windward side, an increased wind velocity enhances the airflow into air inlets of each floor linearly. Optimal wind direction occurs when the wind is perpendicular to window, which maximizing airflow rate and reducing uneven distribution. Higher floors are more sensitive to wind speed and direction changes compared to lower floors. Conversely, the leeward side should be avoided, as wind it weakens airflow rate and reduces overall performance. The interaction between wind and building floors is also important. As the number of floors increases, the wind sensitivity of multi-storey solar chimneys decreases. A 2-storey solar chimney has higher chimneys and better wind energy utilization, can effectively replace single-storey solar chimneys. To optimize ventilation performance in windy, the inlet height should be increased to 0.4–0.6 m, and the cavity gap should be expanded to 0.7–1.5 m. A theoretical model was developed as well, which accurately predicts the solar chimney performance in multi-storey buildings. This study fills a critical gap regarding the ventilation effect of multi-storey solar chimneys in external wind, offering practical guidance for optimizing the designs of multi-storey buildings.