Natural Ventilation and Cooling of a House with a Solar Chimney Coupled with an Earth – To – Air Heat Exchanger

Abstract

A combination of a solar chimney and an earth – to – air heat exchanger (EAHE) for natural ventilation and cooling of a house was studied numerically in this study. The solar chimney creates an air flow through the house, which is based on the solar heat gain. The EAHE consists of underground pipes which are cooled by the earth temperature, which is sufficiently lower than the air temperature at the ground level in hot climate. By combining the two systems together, ambient air can be drawn into the EAHE, cooled, then supplied to the house. The air flow and heat exchange within the system and the house were predicted by a numerical model based on the Computational Fluid Dynamics method. The flow and velocity fields inside the chimney, the house, and the EAHE were predicted with different design parameters of the system, including the dimensions of the chimney and the pipes, the location of the air supply to the house, and the solar heat flux. The induced air flow rate, the air temperature supplied to the house, and the distributions of the air velocity and temperature inside the house were considered. The results show that the required ventilation rate and thermal comfort conditions can be achieved with the proposed system.