How Geothermal Systems Work

The Geothermal Advantage

 

At the heart of a geothermal system are one or more ground source heat pumps, which operate in a manner similar to a common refrigerator. Unlike conventional heating systems that burn fossil fuels or use electricity to create heat, heat pumps simply move heat from one place to another.

The ground and lakes around us represent a vast reservoir of renewable thermal energy stored from the sun. This geothermal energy is estimated to exceed all other energy sources combined by more than two thousand times. At depths below 8 to 10 feet (2.5 to 3 meters), the earth's temperature remains at or near the average annual air temperature above. During the winter, a geothermal system collects this low-grade thermal energy from the earth and concentrates it inside the house or building to provide space heating. For every unit of energy used by a ground source heat pump, a well-designed geothermal system can provide three to four units of heat energy to the building. All ground source heat pumps are rated by an industry standard called the Coefficient of Performance, or COP, which typically range from 3.0 to 4.0. This represents efficiencies of 300% to 400%.

In the summer, the process is reversed and the heat pump moves heat from the building and stores it back in the ground. Alternatively, the heat removed from the building can be used to efficiently heat a swimming pool, domestic hot water, or other parts of the building that require heat.

Ground source heat pumps move heat to and from the earth by circulating fluid through a ground loop. The most common ground loops are described below.

Ground source heat pumps can provide both heating and cooling at efficiencies unachievable by other heating or cooling equipment. If you would like a more detailed explanation of how geothermal systems work, please feel free to contact us and we would be happy to answer any questions you may have.

Four basic types of geothermal energy sources:

 

Horizontal loops

Horizontal loops are often considered when adequate land surface is available. Pipes are placed in trenches, in lengths that range from 100 to 400 feet. Vertical loops are the ideal choice when available land surface is limited. Drilling equipment is used to bore small-diameter holes from 75 to 300 feet deep.

Vertical loops

Vertical loops are the ideal choice when available land surface is limited. Drilling equipment is used to bore small-diameter holes from 75 to 300 feet deep.

Pond (lake) loops

Pond (lake) loops are very economical to install when a body of water is available, because excavation costs are virtually eliminated. Coils of pipe are simply placed on the bottom of the pond or lake. Open loop systems are the fourth type and utilize ground water as a direct energy source. In ideal conditions, an open loop application can be the most economical type of geothermal system.

Open loop systems

Open loop systems are the fourth type and utilize ground water as a direct energy source. In ideal conditions, an open loop application can be the most economical type of geothermal system.

Boiler/Tower Systems

For efficiency upgrades where large geothermal systems are not viable, existing boiler/tower jobs are frequently retrofitted. Hybrid systems incorporate both geothermal loop coupled with down-sized conventional heat rejection or addition equipment (boiler or tower).

View the movie below to find out why a geothermal WaterFurnace
is the smarter, more "centsible" solution:

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Cooling Cycle
Heating Cycle