A geothermal heat pump, also known as a ground source heat pump (GSHP), is a unit that uses the Earth as a heat source. Heat pumps move heat from a source to a sink. With GSHP's the source is the ground outside and the sink is the heating system within the house. They use the same basic system as a refrigerator, which transfers heat from the inside of the refrigerator (source) to the outside (sink).
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