Effects of heated cavities below and above the air channel on the performance of a solar chimney for natural heating

Exploring solar radiation, solar chimneys are widely used in sustainable building design. Solar chimneys can ensure thermal comfort in a house by generating a heating or cooling air flow. For heating applications, the induced air flow is heated and supplied back to the house. In this study, the air flow and heat transfer in a solar chimney for heating were modelled by a numerical simulation based on Computational Fluid Dynamics (CFD) technique. An investigation on the system performance was carried out with the presence of a heated cavity above the top and below the bottom of the air channel. The length and the width of the cavity and the chimney gap have a strong influence on the flow rate and temperature rise through the chimney. The results showed that an appropriate dimension of the heated cavity can enhance the performance of the solar chimney.