9.9.3 Water Source Heat Pumps
9.9.3 Water Source Heat PumpsPond
If a home has source surface water, such as a pond or lake, this type of loop design may be the most economical, since there is no need to dig a trench or a well for the pipes in the ground. In this type of system, the fluid circulates through polyethylene piping in a body of water, just as it does in the ground loops. The pipe may be coiled in a slinky shape to fit more of it into a given amount of space. This loop is recommended only if the water level never drops below six to eight feet at its lowest level, to assure sufficient heat-transfer capability. Pond loops used in a closed system result in no adverse impacts on the aquatic system.
Open-Loop Systems
This type of system uses well(s) or surface body water as the heat exchange fluid that circulates directly through the GHP system. Once it has circulated through the system, the water returns to the ground through the well, a recharge well, or a surface discharge. This option is obviously practical only where there is an adequate supply of relatively clean water, and all local codes and regulations regarding groundwater discharge are met.
