Which type of heat exchanger is most common in geothermal heat pump systems?

In geothermal heat pump systems, the most common type of heat exchanger used is ground-to-water. This configuration utilizes the stable temperatures found in the ground to exchange heat with water circulating through the system. Ground-to-water heat exchangers are effective because they take advantage of the earth's natural thermal properties, allowing for efficient heating and cooling.

As the medium (water) is pumped through underground pipes, it absorbs heat from the ground during the heating season and releases heat to the ground during the cooling season. This process not only maximizes energy efficiency but also reduces reliance on conventional heating and cooling sources, making it a sustainable option for temperature regulation in buildings.

Other configurations, such as air-to-air or water-to-air heat exchangers, utilize different mediums (air or direct water transfers) and may not provide the same efficient heat transfer capabilities or stability that ground-to-water systems offer, particularly in varying outdoor conditions. Water-to-water systems also exist, but they are less common in geothermal applications than the ground-to-water systems, which allow for a more effective energy exchange.