Geothermal technology relies on the
fact that the Earth (beneath the surface) remains at a relatively constant
temperature throughout the year, warmer than the air above it during
the winter and cooler in the summer, very much like a cave. The geothermal
heat pump takes advantage of this by transferring heat stored in the
Earth or in ground water into a building during the winter, and transferring
it out of the building and back into the ground during the summer. The
ground, in other words, acts as a heat source in winter and a heat sink
in summer. *
The system includes three principal components:
• Geothermal earth
connection subsystem
• Geothermal heat
pump subsystem
• Geothermal heat
distribution subsystem
subsystem
Geothermal
For:
• Homeowners
• http://www.igshpa.okstate.edu/geothermal/residential.htm
• Georgia
Tax incentives for installation of Geothermal Heat Pumps
• http://www.dsireusa.org/library/includes/map2.cfm?CurrentPageID=1&State=GA&RE=1
• Federal Commercial
Medium and Large Buildings
• http://www.igshpa.okstate.edu/geothermal/commercial.htm
• Environmental
and Energy Benefits of Geothermal Heat Pumps
(PDF 318 KB)
• http://www.nd.gov/dcs/energy/pubs/renewable/geoben.pdf
EARTH CONNECTION
Using the Earth as a heat source/sink, a series of pipes, commonly called
a "loop," is buried in the ground near the
building to be conditioned. The loop can be buried either vertically or
horizontally. It
circulates a fluid (water, or a mixture of water and antifreeze) that
absorbs heat from, or relinquishes heat to, the surrounding soil, depending
on whether the ambient air is colder or warmer than the soil.
Heat Pump
The geothermal heat pump, also known as the ground source heat pump, is a highly efficient renewable energy technology that is gaining wide acceptance for both residential and commercial buildings. Geothermal heat pumps are used for space heating and cooling, as well as water heating. Its great advantage is that it works by concentrating naturally existing heat, rather than by producing heat through combustion of fossil fuels.
For heating, a geothermal heat pump removes the heat from the fluid in the Earth connection, concentrates it, and then transfers it to the building. For cooling, the process is reversed.
Heat Distribution
Conventional ductwork is generally used to distribute heated or cooled
air from the geothermal heat pump throughout the building. Radiant
heat is becoming an increasingly popular choice in basement and slab environments.
Residential Hot Water
In addition to space conditioning, geothermal heat pumps can be used to
provide domestic hot water when the system is operating. Many residential
systems are now equipped with desuperheaters that transfer excess heat
from the geothermal heat pump's compressor to the house's hot water tank.
A desuperheater provides no hot water during the spring and fall when
the geothermal heat pump system is not operating; however, because the
geothermal heat pump is so much more efficient than other means of water
heating, manufacturers are beginning to offer "full demand"
systems that use a separate heat exchanger to meet all of a household's
hot water needs. These units cost-effectively provide hot water as quickly
as any competing system.
