GeoExchange systems offer an efficient alternative to conventional heating and cooling methods. GeoExchange systems offer a 30-60 percent cost savings advantage over the heating and cooling systems as well as being earth-friendly, comfortable, dependable, safe, and can provide water heating as well. Geothermal heating and cooling systems work by using the earth as a constant temperature thermal mass to draw heat from or dispense heat to, depending on whether the system is heating or cooling.

How It Works

The ground heat exchanger is analogous to a battery. The annual heating and cooling loads are analogous to an electrical draw on the battery. To size a battery you need to know the peak draw as well as the total draw.

GeoExchange heating and cooling systems work by using the earth as a constant temperature thermal mass to draw heat from or dispense heat to, depending on whether the system is heating or cooling. The earth maintains a temperature between 45 to 55 degrees Fahrenheit year round below the frost line. GeoExchange systems work by taking advantage of this constant temperature and the large mass of the earth.

While in heating mode, GeoExchange systems draw heat from the earth by pumping a solution of antifreeze and water through long piping systems, or loops, placed in the ground. Inside the building, a smaller pipe containing a refrigerant evaporates and is then compressed to further heat it to 180 degrees. The refrigerant is then passed through a radiator where the air absorbs the heat and the refrigerant condenses. This cycle is continuously repeated, heating the air within the building in the process. In order to cool a building the process is simply reversed.

Different types of loop systems are used for GeoExchange systems, depending on each individual project. The four types of loops commonly used are: horizontal closed ground loop, vertical closed ground loop, closed loop in a lake/pond, and the open loop well system. Usually, the amount of land available determines the loop system that is used.

Hybrid GeoExchange Systems

Sometimes unique building heating and cooling requirements require the use of a hybrid system. In order to reduce heating and cooling costs, a GeoExchange system can be used in conjunction with conventional heating and cooling components such as a boiler. In a hybrid system, the ground loop is sized to meet the heating or the cooling load of a building, whichever is smaller. Conventional heating and cooling components would then handle any additional heating or cooling capacity needed. Since a hybrid system used a smaller GeoExchange loop system than what would normally be used, the initial installation cost is reduced.