NOVEL DESIGNS TO IMPROVE THE PERFORMANCE OF SOLAR CHIMNEY FOR BUILDING VENTILATION

Abstract

Solar chimneys (SCs) serve as passive devices to induce natural ventilation, utilizing solar radiation to generate buoyancy-driven airflow to improve indoor air quality (IAQ) and thermal comfort. This thesis addresses key gaps in SC research, focusing on enhancing airflow rates and achieving uniform airflow distribution across multiple storeys. Firstly, theoretical analysis revealed that a more uniform outlet velocity can help improve flow rates, leading to the development of a novel staggered split absorber design for single-storey SCs. Secondly, the impact of geometric parameters on flow rates in high-rise SCs was investigated. The optimal shape, identified as the square-root-law structure, was proven highly effective in enhancing the uniformity of airflow rates distribution among storeys through numerical simulations. Finally, the effectiveness of the optimized SC ventilation system in a 10-storey flat was examined, demonstrating that SCs can ensure good IAQ and induce acceptable thermal comfort in Singapore.