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S&B Geothermal

How Ground Source Heat Pumps Cool

Fluid (water and antifreeze) is circulated from the heat pump, through a loop buried below frost level in your yard which returns to the heat pump. During this trip, the water enters the loop field warm and is cooled by the earth. Back at the heat pump, the fluid is run through a heat exchanger where the warm refrigerant is cooled by the fluid. The water leaves the heat exchanger warmer than it entered and is recooled by the earth.

The refrigerant entered the heat exchanger warmed by the home and exits cooler. Due to the low refrigerant boiling temperature, the refrigerant enters the heat exchanger as a gas and is condensed by the loop fluid. This cold refrigerant is then sent to an air coil where the heat pumps blower blows air from the home over the coil. As the air passes over the coil it is cooled and dehumidified and is sent to the home to cool the occupants. The refrigerant is boiled to a warm gas and is sent back to be cooled by the earth loop fluid.

This process continues constantly moving warmth from the home to the earth. As the summer progresses, the earth's temperature will rise. A properly designed and installed system will never rise to the point where the fluid cannot get rid of enough heat to cool the home. Ground source heat pumps operate more efficiently as an air conditioner because the earth is generally cooler than the warm air of summer. Once winter starts, this warm earth becomes the source of heating for the home.

On open systems, water is pumped from the well, warmed in the heat pump and returned to the earth. No water is consumed or contaminated in this process and it becomes available for reuse as it returns to the earth. Some homeowners redirect this water to water their yard or crops on its way back to the earth.

Click here to learn how ground source heat pumps heat.