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Geothermal |
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How
Geothermal Heating and Cooling Systems Work
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Ground source heat pumps can be categorized
as having closed or open loops, and those
loops can be installed in three ways:
horizontally, vertically, or in a pond/lake.
The type chosen depends on the available
land areas and the soil and rock type at the
installation site. These factors will help
determine the most economical choice for
installation of the ground loop.
For closed loop systems, water or antifreeze
solution is circulated through plastic pipes
buried beneath the earth's surface. During
the winter, the fluid collects heat from the
earth and carries it through the system and
into the building. During the summer, the
system reverses itself to cool the building
by pulling heat from the building, carrying
it through the system and placing it in the
ground. This process creates free hot water
in the summer and delivers substantial hot
water savings in the winter.
Open loop systems operate on the same
principle as closed loop systems and can be
installed where an adequate supply of
suitable water is available and open
discharge is feasible. Benefits similar to
the closed loop system are obtained.
Loop Systems: |
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When setting up a
Geothermal heat pump, there are several loop
configurations available. They can either be
vertical, horizontal, or submerged in a
nearby pond or lake. In many cases, a water
well can be used instead. The best
application will depend on the
characteristics of your property. At PDG, we
will show you which type of loop system is
best suited for your home. |
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Vertical Loops are used extensively
where land area is limited or soil
conditions prohibit digging the more
economical horizontal loops. A pair of
pipes with a special U-Bend assembly at the
bottom are inserted into a bore hole that
averages between 150-200 feet deep per ton
of equipment. These holes are then
backfilled with a special grout solution to
ensure good contact with the earth. |
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Horizontal Loops are installed in
areas where the soil conditions allow for
economical excavation. Taking up more
land area than any other loop type, they are
used where space permits. Trenches are
normally about five feet deep with multiples
pipes placed in the trench at different
depths. Normally, several hundred feet
of trench is required, but where space
permits, these loops are considered
desirable. |
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Pond Loops are usually very
economical to install. if a pond or
lake at least eight feet deep is available,
pond loops can utilize the water (rather
than soil) to transfer heat to and from the
pond. A coiled pipe is placed in the
water, covering about 1/2 acre. An
average home would require about 900 feet of
pip. Reduced installation costs and
high performance are characteristic of this
type of loop. |
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