Investigation of the performance of ground-coupled heat exchanger technology for tempering air

Abstract

A horizontal ground heat exchanger has been applied as a simpler sustainability measure in buildings compared to its vertical counterpart, making it more suitable for residential application. A lack of contextual scientific findings within the specific construction culture has precluded its widespread application in the developing world. In this study, an experimental and simulation investigation was carried out on the thermal performance of an air-based horizontal ground-coupled heat exchanger buried 3 m below the ground. The study was performed in the tropical climate of Mauritius with a focus on space cooling. The ground temperature and air temperature inside the pipeline at several locations of the installation was measured. A CFD simulation model was developed and calibrated against the experimental data, which allowed further analyses on the influence of system parameters on performance. The study allowed to confirm the performance of the technology for application as a sustainability measure in the local construction industry and to identify practical challenge that need to be addressed. A drop in temperature of up to 5C was achieved at 2.3 m/s and 8C at 4 m/s. The latter result holds promise to achieve thermal comfort by achieving indoor air temperature of 27 C or lower when ambient air is at 33-34C during typical summer periods.