Ground-source systems refer to any heat pump that uses the ground, groundwater, or surface water. Ground-coupled heat pumps (GCHPs) are a subset of ground-source heat pumps (GSHPs) and typically consist of water-to-air heat pumps linked to a network of tubing buried in the ground or placed in surface water reservoirs. The unit is most often located indoors with a traditional air distribution system. The ground coil is typically constructed of thermally fused plastic tubing in which water or a water-antifreeze solution is circulated. In some cases, a water-to-water heat pump is used. Work is also in progress to determine the effectiveness of direct burial of refrigerant tubing in the ground.

Groundwater heat pumps (GWHPs) are the second subset of GSHPs. GWHPs utilize an open loop in which water is pumped from the ground or a reservoir through the heat pump. While the development of the variable-speed ground-source heat pump (VSGSHP) is for the closed-loop GCHP, it could also be applied to a GWHP system.