Ground-Source Heat Pump
Closed-loop, ground-coupled heat pump systems (also called ground-source heat pumps) use a vertical or horizontal heat exchanger buried below the frost line to collect or reject heat. This heat exchanger circulates water in a closed loop to reject or collect heat from the ground, lake, or pond. The water is treated to prevent freezing and to reduce corrosion and scaling. Horizontal heat exchangers need approximately 500 feet of coil for each ton of cooling capacity. Vertical heat exchangers need about 300 feet of underground coil per ton.
Ground-coupled heat pump systems are most appropriate where land is available for burying the pipe and soil conditions are suitable for easy excavation or drilling. However, material and installation costs should always be estimated for your situation by a qualified contractor installer or drill professional since general guidelines can be misleading.