GEOTHERMAL SYSTEM
A typical Earth Energy System, known as a Geothermal System, consists of three parts; a loop, the heat pump and a distribution system.
A loop is built of plastic pipe buried in the ground outside the home either in a horizontal trench or through holes drilled down into the earth to form a vertical loop. It may also be laid on the bottom of a nearby lake or pond if there is a suitable one available. The Geothermal system circulates the liquid heat transfer fluid through the loop to the heat pump which is located inside the home. The heat pump chills the fluid and circulates the heat extracted from it throughout the home. The chilled liquid is then pumped back into the loop and, because it is now colder than the ground through which it passes, is able to draw more heat from the surrounding soil. This is free energy.
The loops are referred to as closed loops as the same liquid continues to circulate through the closed system over and over again.
Another system is referred to as an open loop system in which ground water or well water is pumped directly through the heat pump. The heat pump cools the water which is then returned to a well. To run this type of system, two reliable wells are needed with water that contains few dissolved minerals that can cause scale build up or rust over time, as it will damage the heat exchanger.
In both closed or open loop systems, the pump circulates liquid through the loop and the heat pump, which chills the liquid, that is collects the heat in it, and circulates it back through the loop to pick up more heat. A large home requires a larger heat pump and ground loop, with a circulation pump to match.
When the Geothermal System has taken the available heat from the ground loop and upgraded it to a temperature to use in the home, it sends the heat evenly through a distribution system to all parts of the building.
Forced air is the most commonly used distribution system, although hot water systems can be used.
In a forced air system, the heat pump uses a heat exchanger to take the heat energy from the refrigerant to heat the air that is blown over it. The air is directed through ducts to the rooms throughout the home. This has several advantages; it can distribute fresh, outside air throughout the home; it can air condition the home by taking the heat from the air in the home and transferring it to the ground loop; and it can filter the air in the home as it is circulated..
A hot water heating system will require larger or more radiators than in previously used systems. Currently available heat pumps can heat water to no more than 50 degrees C. Hot water base board heaters are designed to operate with water at 65 to 70 degrees.
Radiant floor systems can also be used; but must be designed to operate within the temperature capabilities of the Geothermal system.
These choices can be made according to the needs of the home owner.