Ventilation evaluation of wall-mounted solar chimney for multi-room building

Previous studies on solar chimneys have primarily focused on single-room or simplified multi-zone buildings, and their applicability to multi-room structures with complex coupled airflow paths remains unknown. This study investigates the performance of solar chimneys in multi-room buildings. Numerical simulations are conducted to analyze the effects of forced and unforced vent sizes, revealing the influence of key design parameters, and a theoretical model is developed to predict their performance. The results show that internal vent configuration plays a dominant role in ventilation performance. A minimum vent height of 0.2 m is required to achieve 6 ACH in a corridor connected to four rooms, while positioning the forced vent approximately 0.1 m higher than the unforced vent enhances ventilation performance with improved design efficiency. Arranging forced and unforced vents in parallel shortens airflow paths and increases airflow efficiency by 10.2–13.7%. Unlike single-room systems, the ventilation rate in multi-room buildings exhibits a parabolic relationship with inlet height and cavity width, with optimal values around 0.2–0.3 m, resulting from the balance between buoyancy-driven flow and increased resistance along extended airflow paths. Excessively high inlet positions weaken thermal buoyancy and reduce chimney performance. Increasing window size improves ventilation by up to 11%, although further enlargement leads to diminishing returns. The proposed theoretical model demonstrates good predictive capability for airflow performance in multi-room configurations. This study addresses the lack of theoretical understanding of multi-room solar chimneys and provides a basis for their optimized design and application.