The Potential of Earth-Air Heat Exchanger (EAHE) For Low-Energy Cooling Of Residential Buildings In Saudi Arabia (KSA)

Abstract

This thesis investigates the possibility of using Earth–Air Heat Exchanger (EAHE) systems to provide thermal comfort in the Kingdom of Saudi Arabia (KSA). Recently, the request for air conditioners in residential buildings during the summer has increased, leading to a significant escalation in energy consumption. The main objective of this investigation is to look for an alternative solution to reduce or eliminate the use of air conditioners. EAHE is a promising passive cooling strategy that can help maintain indoor comfort while reducing energy consumption for residential buildings in KSA. EAHE is a subterranean air conditioning system that takes advantage of ground soil temperature by using it as a heat sink or heat source for heating and cooling the interiors of buildings. This system uses a simple method of drawing air from its intake and then passing it through special pipes. Once in place, the process releases air from its outlet into the interior of the building. As the air passes through the pipes, it exchanges heat with the surrounding soil. This process allows the air to be warm in the winter and cool in the summer because of the temperature difference between the air and the ground. Since KSA climate is hot and arid, this study will primarily focus on cooling methods. To meet the requirements of the investigation, this study used the energy simulation software DesignBuilder to evaluate the potential of the EAHE system for cooling residential buildings in KSA, specifically in Dhahran city. Based on data gathered from previous studies, the EAHE system used pipe lengths of 70 m and a radius of 0.1 m. The pipes were buried 3 m deep in heavy and moist soil. This study found that the difference between using heavy and dry (bare) soil and heavy and damp (covered) soil was 4.9°C. Simulation results showed that the EAHE in conjunction with thermal insulated buildings could reduce temperatures between the out dried bulb temperature and indoor operative air temperature. This also has the potential to provide thermal comfort in residential buildings during peak hours in the summer, especially in May and June where the reduction of the operative temperatures were 4.79°C and 4.45°C, respectively. This study concluded that EAHE is a good solution for reducing energy consumption when it is in conjunction with thermal insulation.