The Federal Government is now offering Tax incentives for Geothemal Units installed in 2009 and 2010! See a representative or call us for details.
A geothermal system is a heating and cooling unit designed to extract the natural heat stored in the ground during the winter and discharge heat from air conditioning to the relatively cool ground in the summer. A geothermal system can also heat water. The sun shining on the earth warms the ground to maintain a relatively constant temperature of about 52 degrees Fahrenheit year round in southern Michigan at a depth of 4 to 6 feet.
Heat is extracted from the earth during the winter or heat is discharged to the earth during the summer air conditioning season by one of four types of installations.
If a horizontal loop system were installed, it would involve the excavation of parallel trenches, each 5 feet deep and 3 feet wide and about 130 to 150 feet long. The minimum distance between each trench is about 15 feet. Each parallel trench can run in any direction; that is they don't have to be side by side. 600 feet of ¾ inch polyethylene pipe are placed in each trench resembling a slinky laid flat on the bottom of the 3-foot wide trench. All parallel trenches are connected to a 1-¼ inch supply and return header which enters the house through the basement to the geothermal flow center. Alternative horizontal loops use 2, 4, or 6 pipes per trench. A 2-pipe trench would be about 1 to 2 feet wide and about 400 feet long. As more pipes are added to the parallel loops the length of the trench is reduced.
The vertical loop would involve vertical boreholes 4 inches in diameter drilled about 150 feet each. Each borehole would be separated from the next by about 10 feet. Two ¾ inch polyethylene pipes are inserted into the 150-foot borehole. The pipes are connected at the bottom using a U-bend. The borehole is then filled with bentonite clay to bond the pipe to the earth and prevent surface water from entering ground water aquifers. The individual wells are joined to a 1-¼ inch header at a depth of 5 feet below grade. The supply and return header then enters the house through the basement wall.
Where ground water is abundant, a water well can also be used as the energy source/sink, reducing the installed cost by eliminating the closed loop. However, a return well or acceptable surface discharge is required. In addition, an open loop system will require periodic cleaning of the heat exchanger to remove mineral deposits. This is generally done annually.
A pond loop system consists of 300 foot coils of ¾ inch polyethylene pipe circuited in parallel via 1 ¼ inch polyethylene header pipes. The header and coil assembly is mounted to a PVC frame which holds the coils at the proper spacing and depth allowing water to flow underneath and through the center of each coil. Concrete blocks are attached to the base of the PVC frame and the entire structure is floated to the desired location in the pond. Once in position the pond loop is flushed and filled from the basement through 1 ¼" polyethylene header pipes sinking the pond loop to the bottom of the pond.
What are the benefits of geothermal?
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