Ground-to-water and ground-to-air heat pumps
In these systems, coil A in Figure 4.2 is buried underground and heat is extracted from the ground. These heat pump systems have limited use. Practical applications are limited to space heating where the total heating or cooling effect is small, and the ground coil size is equally small. This system requires the burial of several meters of pipe per ton of refrigeration, thus requiring a large amount of land.