What is geothermal?

With the 'Green' movement in full swing many people are hearing the word geothermal, and how it can help you save energy. In HVAC, geothermal heat pumps are used the same way your conventional (air to air) systems work. The important difference is that a geothermal heat pump uses water that is cooled by the Earth to cool the refrigerant whereas a conventional heat pump uses air to cool the refrigerant during a cooling cycle. When the temperature outside is in the 90's or even 100's, as it does here in Pensacola, that hot air is beinused to cool the refrigerant. With a geothermal unit the water in the loops, typically 70 degrees cools the refrigerant therefore making it much more efficient. Similarly the geothermal heat pump uses hotter water to heat the refrigerant during the winter while an air to air heat pump uses 30-40 degree air.