Roger Eldridge, Partner uses a series of diagrams to explain the basic principles of water source geothermal systems.
A geothermal system is explained in the following steps.
In small homes 300 ft of horizontal pipes are installed 4 ft underground or a 300 ft vertical well is drilled. In larger buildings there may be many 300 to 500 ft wells.
The pipes are connected in a loop and sealed. This is the first of three loops.
An electric pump is installed to circulate a mix of water and antifreeze. NO GROUND WATER IS EVER USED IN THE SYSTEM.
The fluid in the loop is heated or cooled to 60° F by the earth.
The heat pump unit is installed inside the building. The refrigerant in a second closed loop is compressed by the compressor. In cold weather, as the refrigerant goes through the coils it removes heat from the ground loop. After moving through a pressure reducer, the refrigerant gives off heat.
The supply duct work and a fan or blower are installed and move the heated air through the heat exchanger to the rooms of the building.
The return air ducts are installed and return the air to the blower. This completes a third loop.
When it is hot outside, the compressor is reversed. The 60° F water in the ground loop is now use to cool the coils and via the heat exchanger and ducts cools the inside air.
NO NOISY EQUIPMENT NEEDS TO BE MOUNTED OUTSIDE THE BUILDING OR ON THE ROOF.
The US Environmental Protection Agency (EPA) says geothermal heat pumps are among the most efficient and comfortable heating and cooling technologies currently available, because they use the earth’s natural heat to provide heating, cooling, and often, water heating. Click here for the EPA reports.