Water Well With Re-injection (open loop)
A standard water well can be utilized to serve a geothermal heat pump with a stable supply of water from the shallow earth that usually does not vary in temperature throughout the year.
Instead of bringing water into the house and see it lost to a gray water, sewer drain, or outside irrigation, the heat pump can subtract or add some thermal energy from this supply and send it back to the aquifer without any losses. The imported, pumped water from the well is delivered to the heat pump’s heat exchanger at the same temperature of the underground formation, and that eliminates one heat exchange loop compared to other borehole, horizontal, or pond loop heat transfer styles. As a result, such heat exchangers propel their heat pumps to higher nameplate efficiencies, transferring more heat with fewer kilowatt-hours.
If the imported well product is free of fine sand or grit, no additional filters will be needed. Otherwise, the heat pump’s heat exchanger may experience wear inside its heat exchanger’s pipes, possibly necessitating a costly replacement.