How a Geothermal System Works:
Standard heat pumps heat the indoors by absorbing heat from the outside air and transferring it to the indoor air through a mechanical compression cycle. During the summer, the heat pump simply reverses its heat absorbing process. This method is efficient, but it is limited because of fluctuating outdoor temperatures.
Unlike the air, the earth is very stable in temperature. In Southern Maryland, at depths from 4 to 500 feet, the average temperature is around 50 to 55 degrees F year-round. The geothermal heat pump makes efficient use of the earth’s stable temperature. As a result, homes and businesses can be heated and cooled at maximum efficiency regardless of the outdoor air temperature.
Closed Loop Geothermal Systems:
All geothermal systems utilize a compressor, a refrigerant, and an indoor heat exchanger connected to the duct system. The only thing that may vary is the method by which the earth’s energy is absorbed and released.
The closed loop system circulates a water and anti-freeze solution through a piping system which may be buried vertically or horizontally. This solution fills the loop and is constantly circulated by a low wattage pump. The following is a description of the closed loop systems most commonly used in the Southern Maryland area.
Vertical loop systems are popular for sites with limited space or with well-established yards and trees because the system disturbs minimal ground area. One loop is required for each ton of heat pump capacity. Each loop is inserted into a bore hole, 150 feet deep and six inches in diameter.
Horizontal loop systems are used when there is sufficient open space such as a field, large yard, or parking lot. Basically, the soil classification and actual available open space dictate the design. The length of pipe runs from 250 to 550 feet per ton of heat pump capacity, depending on soil conditions and loop design.
- lowest heating and cooling costs available
- no outdoor unit
- long equipment life
- truly renewable energy source
- no defrost cycle
- low maintenance
- good humidity control
- system can be used to heat water, reducing energy costs
Since geothermal heat pumps utilize a stable energy source for heat transfer, they also heat water for domestic use very efficiently. The system makes use of excess heat energy from the compressor to heat water. This method can reduce conventional water heating costs by at least 50 percent.
No matter which loop configuration or what brand of heat pump you select, a geothermal heating and cooling system is the most energy efficient heating, cooling, and water heating system available.
Actual costs of operation will depend on the size of your home or business, selected room temperatures, and hot water consumption. But no matter what the requirements, a geothermal heating and cooling system will save you in energy costs for years to come.