To design borehole heat exchangers (BHE) for Ground Source Heat Pumps (GSHP) or Underground Thermal Energy Storage (UTES), the knowledge of underground thermal properties is paramount. In small plants (residential houses), these parameters usually are estimated. However, for larger plants (commercial GSHP or UTES) the thermal conductivity should be measured on site. A useful tool to do so is a ...

The number of Slinky-coil horizontal ground heat exchangers (HGHEs) has been increasing in geothermal heat pump (GHP) systems due to the low initial cost. The performance of the Slinky-coils, however, has not been successfully predicted with good accuracy since the complicated shape of the Slinky-coils is not easy to model either analytically or numerically. To enable this, Fujii et al. (2012) ...