Performance and airflow analysis of new solar chimney design with multiple openings for building ventilation

Abstract

Solar energy continues to play a vital role in reducing energy consumption in the buildings sector. One such application is the solar chimney, which uses solar energy to enhance natural ventilation by inducing air into the building. In this study, the performance, heat transfer, and airflow characteristics of a newly designed solar chimney were analyzed using commercial Computational Fluid Dynamics (CFD) software. The Renormalization Group (RNG) k-epsilon turbulence model was used to predict the chimney’s volumetric airflow rate. The study aimed to: a) evaluate the ventilation performance of the chimney under varying wind speeds with a fixed heat flux of 500 W/m2, and b) investigate how different glass tilt angles affect the airflow rate. Results showed that both base and reverse outlet blade arrangements achieved a maximum flow rate of 4.4 kg/s. The highest recorded flow rate was 4.8 kg/s with a 75° blade angle and five openings, making it the most effective setup at low wind speeds. This flow rate surpasses those reported in earlier studies (0.04–0.13 kg/s). The system provides a sustainable alternative to mechanical ventilation, resulting in lower energy consumption in buildings.