Geothermal cooling solutions for rural communities at Homa Bay, Kenya: a CFD modelling study

Abstract

A Computational Fluid Dynamics (CFD) modelling study has been presented to analyse the cooling impact of a geothermal cooling system based on the Earth-Air-Tunnel-Heat-Exchanger (EATHE) concept to provide passive cooling to heat-stressed vulnerable people in Homa Bay, Kenya. Like many places on earth, Homa Bay is experiencing extreme environmental heat. The novelty and significance of the present work lies in demonstrating the effectiveness of the technology for a field application using real-world data. Two different pipe arrangement designs, a straight pipe and a serpentine pipe, were investigated for their cooling effect. The inlet and boundary conditions were set using the air and ground surface temperature data available from the NASA Satellite for Homa Bay, Kenya. The simulation results show that the lower the air velocity the better the cooling effect and a 40 m long straight or serpentine pipe with a 0.1 m internal diameter and 1.0 m/s air velocity can provide a 3°C cooling on the hottest days of the year. The performance difference between a straight pipe and a serpentine pipe is negligible, and owing to the lower space requirements, a serpentine design is recommended.

Keywords

• Geothermal cooling
• climate change
• CFD
• EATHE
• UNSDG