How does geothermal heating and cooling work?

Geothermal heat pumps transfer heat between the ground and your home through a series of buried pipes

Harnessing Geothermal Energy

Geothermal heat pumps take advantage of the solar energy stored just below the surface of the ground.  40 – 60% of the Sun’s energy is directly absorbed into the ground, making the Earth a giant solar panel. Geothermal heat pumps transfer energy between the ground and your home through a series of buried, high-density, poly-ethylene pipes. The pipes are filled with a water solution and sealed using heat-fusion to weld pipe to pipe. These pipes are called an earth loop.

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Geothermal Heating

In the heating mode, heat is absorbed from the ground and pumped into your home.  The water circulating in the earth loop is colder than the surrounding ground.

This causes the water to absorb energy, in the form of heat, from the earth. The water carries this energy to the heat exchanger in the pump. In the heat exchanger, refrigerant absorbs the heat energy from the water. The water now leaves the heat exchanger at a colder temperature, and circulates through the earth loop to pick up more energy.

The refrigerant gas, which contains energy gained from the earth loop, travels from the heat exchanger to the compressor. In the compressor, the refrigerant temperature rises to 160°. The superheated refrigerant travels to the air heat exchanger. Here, the heat pump's blower circulates air across the air coil, increasing the temperature of the air, which is blown through ductwork to heat the home. After refrigerant releases its heat energy to the air, it then flows to the earth loop heat exchanger to start the cycle again.

Geothermal Cooling

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In the cooling mode, heat is pumped out of your home and released into the ground.  The water circulating in the earth loop is warmer than the surrounding ground. This causes the water to release energy, in the form of heat, into the earth. In the heat exchanger, hot refrigerant gas from the compressor releases its heat into the water. This causes the water to increase in temperature, and release the heat to the ground.

The refrigerant, which has released its heat energy and became a cold liquid; now travels to the heat exchanger. Here the heat pump's blower circulates warm, humid air across the cold air coil. The air is then blown through ductwork to cool the home. The refrigerant in the air coil picks up the heat energy from the air, and travels to the compressor. When the refrigerant leaves the compressor, it then flows to the earth loop heat exchanger to start the cycle again. The system has no carbon dioxide emissions or any other negative effects on the environment.