Although many parts of the country experience seasonal temperature extremes — from scorching heat in the summer to sub-zero cold in the winter—a few feet below the earth’s surface the ground remains at a relatively constant temperature.
Depending on latitude, ground temperatures range or average locally (9°C) Like a cave, this ground temperature is warmer than the air above it during the winter and cooler than the air in the summer.
The GHP (Geothermal Heat Pumps) takes advantage of this by exchanging heat with the earth through a ground heat exchanger.
As with any heat pump, geothermal heat pumps are able to heat, cool, and, if so equipped with a desuperheater, supply the house with hot water.
Some models of geothermal systems are available with two-speed or variable speed compressors and variable fans for more comfort and energy savings.
Relative to air-source heat pumps, they are quieter, last longer, need little maintenance, and do not depend on the temperature of the outside air.