Geothermal Energy Systems
Building Blocks of Sustainability
"We are moving energy not creating energy, so in any terms, geothermal heating and cooling is the most environmentally friendly and most efficient system, no matter how you look at it. Eer of 26 and cop of 5/6..."
The heating cycle
The cooling cycle
Hot water
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The heating cycle
1. Antifreeze solution is brought back to the heat pump inside the building via pumps, from the ground.
2. Heat is transferred to the refrigerant in the primary coil, which boils to become a low temp vapour.
3. The antifreeze is then pumped back into the earth, and heated again.
4. Reversing valve now directs the refrigerant vapor to the compressor. The vapor is then compressed, which reduces its volume and causes it to heat up.
5. Reversing valve directs the now hot gas to the condensing coil, where it gives up its heat to the air that is blowing across the coil.
6. Having given up the heat, the refrigerant now passes through the expansion device, where it’s temperature and pressures are dropped before it returns to heat exchanger.
hot water
1. A de sup heater or a heat exchanger exists in the heat pump.
2. This takes heat from the hot refrigerant, which has boiled from the ground temperature coming up, after it leaves the compressor.
3. Water from the building is pumped through the coil ahead of the condenser coil, to allow for some of the heat that would have been dissipated at the condenser, to be used to heat the water.
4. This works particularly well in the summer months, as we are extracting large amounts of heat through the coil, and in the winter months when the heat pumps balance point is not working at full capacity. I.e.. The temperatures are mild, not lower than 5 degrees centigrade.
5. This is ideal for South African conditions.
The cooling cycle
1. This is the reverse of the heating cycle.
2. The direction of the flow is reversed by the reversing valve in the heat pump.
3. The refrigerant picks up the heat from the building, and transfers the heat to the antifreeze.
4. The heat is then pumped underground as a heat sink.
5. The earth will naturally accept any quantity of heat at any given time.
6. Because the refrigerant is rapidly cooled by the extraction of heat, the coldness is then transferred with the constant temperature coming back, to the coil and released via blowing over the coil, which then gives you your air conditioning.
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