How is heat transferred between the earth and the home or building?

The earth has the ability to absorb and store heat energy. To use that stored energy, heat is extracted from the earth through a liquid medium (groundwater or an anti-freeze solution) and is pumped to the heat pump or heat exchanger. There, the heat is used to heat the air. In summer, the process is reversed and indoor heat is extracted from indoors and transferred to the earth through the liquid.