Geothermal Energy
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A geothermal heating and cooling system uses the near constant ground
temperatures in the earth's upper layer as a thermal energy storage bank where
energy can either be extracted or added as needed. There are three main components of a geothermal heating and
cooling system: the ground heat exchanger (GHE), the heat pump, and the
building distribution system.
The GHE works as a heat source by releasing energy stored within the earth during system heating operation, and conversely as a heat sink to store energy back into the earth during the system cooling operation. One type of GHE commonly used is a closed loop piping arrangement. A closed loop system uses a system of continuous underground piping where both ends are connected to the heat pump. Water or a mixture of water and an environmentally friendly anti-freeze is used as the heat transfer fluid and is circulated through the piping to transfer heat between the heat pump and the earth
The heat pump is a machine which operates on electricity and is located
within the building. It uses a compressor and refrigerant circuit to extract
heat or to reject heat back to the GHE supplied water in conjunction with the
mode of operation. Depending on
the type of heat pump, either heating or cooling air, or hot or chilled water
can be made to be used for space conditioning within the building. Heat pumps are also beneficial due to
the fact that their energy efficiency ratings can be in the area of 400%; that
means for every unit of energy input to the machine, the resulting output is
four times greater.
The distribution system in the building can consist of air ducts or hydronic (fluid based) terminal components such as radiant floor tubing to provide comfort control to the building.
How it is used in the school: