Comparison of heat exchange rates between straight and slinky horizontal ground heat exchanger.

Horizontal ground heat exchanger (HGHE) operation in ground source heat pump systems is prone to unstable thermal performance due to temporal weathers and seasonal variations. Therefore, the design of such installation is important to ensure the optimum efficiency during its operation. In this work, the numerical modelling of HGHE operation in different configurations was modelled to predict the outlet temperature and heat exchange rate. The effect of pipe materials of different thermal properties on heat exchange rate of HGHE operation was also studied. The analysis includes comparison of heat exchange rates between straight and slinky configuration. Although the heat exchange per pipe length for slinky configuration is lower, the heat exchange per trench length outperforms the straight configuration due to the greater surface area provided. Copper pipe shows a significant increase in thermal performance in HGHE operation attributed by superior thermal properties compared to the commonly used polyethylene pipe.