Why is a GHP better than an air-source heat pump?
Because of the density of the earth and the water stored within it, the earth is able store tremendous quantities of heat from the sun. In nature, few substances have a higher “specific heat capacity,” making it an ideal heat storage medium. Air, on the other hand has a very low specific heat capacity. It would be necessary to move 3,472 cubic feet of air across the heat exchanger of an air-source heat pump in order to expose that heat exchanger to the same quantity of heat that is stored in a cubic foot of water (7-1/2 gallons).
