For the past week I've begun researching Geoexchange or the process of how Geothermal Heat Pumps work. A geothermal heat pump works by utilizing the earth as either a source or sink depending on the time of year. In the winter the area beneath what is called the freeze line is warm in comparison to the ambient temperature. In the summer the earth is cooler. Liquids such as types of refrigerant or mixtures of water and anti-freeze make thermal connections with the ground and are either heated or cooled.