Passive Solar Chimney Ventilation Efficiency in a Single Enclosed Space

This study numerically investigates passive solar chimney design with emphasis on the coupled influence of geometric and thermal parameters on air inlet flow. While prior studies have examined individual factors such as window height or chimney height, their combined effects have not been sufficiently explored. A validated CFD model was employed to analyze the roles of absorber wall temperature, window area, air inlet height, and cavity width in driving the chimney effect. Results indicate that increasing the absorber wall temperature enhances the air inlet flow by up to a 1.9‐fold increase, whereas enlarging the window area produces the strongest effect, with air inlet flow up to 9.2 times higher. In contrast, greater air inlet height and wider cavity width reduce air inlet flow by 2.2% to 6.1% and 29.5% to 35.2%, respectively. The optimal configuration, consisting of a 60°C absorber wall as the primary thermal parameter, 0.9 m² window area, 0.1 m air inlet height, and 0.1 m cavity width, achieves a maximum air inlet flow of 0.2785 kg/m·s. The novelty of this study lies in being the first to systematically simulate different window areas in combination with air inlet height, cavity width, and absorber wall temperature, thereby revealing the interactive effects among these parameters on air inlet flow performance. These findings provide actionable design strategies to enhance passive ventilation, reduce reliance on mechanical ventilation, and further improve building energy efficiency.