Geo-Thermal

Geo-Thermal

Geo Energy, geo exchange, geothermal heat pump systems; no need to be confused, they all mean the same thing. They all describe a sustainable resource that lies in the ground at your location. Here's how it works.

 A typical air conditioning system draws heat from the inside of a residence or commercial building and discharges it to the air outside using a compressor and fan. As you might expect, on hot days when the A/C is used the most, it is difficult to shed heat into the already hot outside air. The system is very inefficient and must run a long time to remove heat.Conversely in the winter, the air source heat pump tries to draw heat out of already cold air. Likewise, it struggles to draw heat from the frigid air, and must also run a long time.

Geothermal is different. At a depth of 4 to 6 feet below the frost line the ground temperature of the earth remains relatively constant throughout the year. Ground source heat pumps (GSHP) are designed to capitalize on this near constant temperature. Using a properly constructed ground heat exchanger (the ground loop or loops), they harness the thermal energy stored in the ground beneath your site.

Geothermal installations are integrated systems consisting of three major sub-systems to include:  1. Air distribution within the structure (air ducts and blowers circulate the air throughout to control the climate within the structure), 2. Ground source heat pumps (mechanical device to drive or "pump" the heat between the two other subsystems. GSHP work most efficiently when the entering liquid from the ground exchanger remains within a range of 40 to 80 degrees) & 3. Ground heat exchangers (in-ground piping (ground loop or loops) arranged in a grid that makes contact with the earth to facilitate heat exchange. Typical ground heat exchangers are constructed of plastic tubing encased in grout creating improved thermal conductivity. These are referred to as closed loop systems. An open loop system uses groundwater from an ordinary well as a heat source. The groundwater is pumped into the GSHP unit where heat is extracted and the water is disposed of back into the ground. These open loop systems are commonly called "pump and dump" systems. Poor water quality can cause serious problems in open loop systems. Mineral deposits can build up inside the GSHP.Impurities, particularly iron, can eventually clog a return well.