Making Ground Connections for GeoThermal Cooling Heating Residential
View diagrams of the various ground connections for geothermal cooling heating residential properties.
Making The GroundConnection
The unique aspect of the geothermal cooling heating residential system, and the key to its lengthy list of benefits, is the ground loop. The ground loop provides the means of transferring heat to the earth in summer, and extracting heat from the earth in winter.
Diagram Geothermal Vertical Loop
Physically, the “ground loop” consists of several lengths of plastic pipe typically installed either in horizontal trenches or vertical holes that are sub-sequently covered with earth and landscaping of your choice.
Water inside the ground loop piping is pumped through a heat exchanger in the geoexchange unit. In the summer, it absorbs heat from the refrigerant hot zone and carries it to the ground through the ground connections loop piping.
Diagram Geothermal Horizontal Loop
In winter, it absorbs heat from the earth through the ground loop, and then transfers that heat to the refrigerant cold zone.
The length of the ground loop will be determined by the heating and cooling loads, which are determined in turn by the size of your home, its design and construction, its orientation, and the climate where you live.
Diagram Geothermal Closed Loop Vertical
Whether the ground loop is most efficiently installed in horizontal trenches or in vertical bore holes depends on the type of soil near the surface (rocky, sandy, clay-laden, etc.), the geology of the deeper terrain in your area, and the amount of land available.
Diagram Geothermal Closed Loop Horizontal
Generally, horizontal loops are less expensive to install, but require more land area. Vertical holes require much less land area, but require the expense of drilling.
Another ground connection scheme for geothermal cooling heating residential systems—called an open loop system-involves using wells instead of closed loop piping. Where water is plentiful, it can be pumped out of a well, through the heat exchanger at the geoexchange unit, and then pumped back into another well to return to the groundwater.
Diagram GeoThermal Pond Loop
Since the water merely absorbs or gives up heat, but is not altered in any other way, it leaves the geoexchange unit as pure as it was when it entered it. Any one of these installation schemes results in the same high efficiency, when properly sized.
Moreover, once the ground connections loop is installed, you can typically forget about it. The polyethylene piping (the same type used for cross-country natural gas lines) does not degrade, corrode, or break down in ground or water contact, so sound installations are expected to last 50 years or more.
Free Hot Water
As a side benefit, most geothermal cooling heating residential systems can be designed to produce free hot water during the summer, by using waste heat extracted from the interior air during the air conditioning season.
Even in the winter, the geothermal cooling heating residential unit can often help to reduce the use of electricity or gas by the hot water heater.
Premium Comfort Year Round
One of the complaints often heard from the owners of standard heat pumps is that the air coming from the vents in the winter is cool, creating a sense of draftiness.
While the air is actually warmer than room temperature by several degrees, it is much cooler than the average person’s skin temperature.
Heat transfer principle #1 says that heat will flow from our skin (an area of warmer temperature) to the air coming from the vents (an area of cooler temperature). And that makes the air feel cold and “drafty.”
Geoexchange systems don’t have this problem. Because the ground temperature is much warmer than typical winter air temperatures, the geoexchange system can make the air much warmer than our skin—typically well over 100°F.
Since the air from the vents is at a higher temperature than our skin, heat flows from the air to our skin, making us feel warm and cozy.
Geoexchange systems also provide superior year-round humidity control, and modular designs often make zoned heating and air conditioning practical— for even more comfort control through the entire house.
Thank you to Geothermal Heat Pump Consortium at GeoExchange.Org for the above diagrams and information.
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