A geothermal heat pump (also known as a ground-source heat pump) transfers energy from the ground as a component of heating, cooling, and water-heating systems. A collector hose filled with a carrier fluid (water or a combination of water and antifreeze) is installed in a borehole which is drilled into a geothermal aquifer. In colder months, this circulating carrier fluid absorbs heat from the surrounding bedrock, which is then extracted by the heat pump for use in space-heating via piping connected to the heat exchanger. During the warmer months the process is reversed: heat from the air is transferred to the heat exchanger and into the fluid. As it moves through the pipes, the heat is dispersed to the rocks, soil, and groundwater. (en)