Development of a high-efficiency and cost-effective ground source heat pump system for hot-climate applications

This paper investigates the possibility of using a dry fluid cooler with advanced control strategies in a vertical closed-loop GSHP system to reduce the borehole size with the intention of increasing the cost-effectiveness of the system without compromising system efficiency. The developed system is expected to be a game changer in the residential sector of the USA involving the use of high-efficiency heat pump systems as a substitute for conventional systems for space cooling and heating in hot/warm climates. The simulation results show that (1) the use of a dry fluid cooler with advanced control strategies in a GSHP system contributes to increasing or maintaining the GSHP system's efficiency in the long run by balancing the heating and cooling through charging thermal energy to the ground in hot climates; (2) the concept of integrating a dry fluid cooler into a GSHP system with advanced control strategies is proven to be effective for the studied house located in hot climates, such as Miami. In comparison to a conventional GSHP system, the initial system costs can be reduced by up to around 14% by shortening the borehole length without compromising system efficiency because of the use of a dry fluid cooler.