How Does a Geothermal, Ground-Source Heat Pump Work?
More recently, even more advanced and efficient heating and cooling systems have emerged using the geoexchange process. Sometimes called geothermal or ground-source heat pumps, these systems move or transfer heat like the air-source heat pumps. However, they exchange heat with the earth rather than the outdoor air.
Since earth temperature remains relatively constant throughout the year, geoexchange systems operate more efficiently than air-source heat pumps and generally without the use of resistance heat. And because they are working from those constant earth temperatures, there are no blasts of hot air or “cold blow” as with other systems.
Nearly all geoexchange systems on the market have the ability to provide low-cost domestic hot water, further increasing their operating efficiency. Thus, geoexchange systems are generally 2.5 to 4 or more times more efficient than resistance heating and water heating alone, and have no combustion or indoor air pollutants.
Since there is no outdoor unit (as with air-source heat pumps or the central air conditioners used with combustion-based systems), no weather-related maintenance is required.
Although their installation cost is somewhat higher due to the required underground connections for heat transfer to and from the earth, geoexchange systems provide low operating and maintenance cost and greater comfort.