Efficiency
Geothermal heat pumps are much more efficient than air source heat pumps
because earth temperatures are much more uniform through the year than air
temperatures. Not only are earth temperatures more constant, but also the range
of temperatures in ground water is rather small in the United States, varying
from upper 40s to upper 70s nationwide.
To further improve efficiency, many manufacturers use variable-speed,
electronically-controlled motors on the duct system fans. Depending on unit
size, manufacturers may opt for reciprocating, inertia, rotary, or scroll
compressors -- all of which are hermetically sealed and mounted in the indoor
cabinet. Some advanced heat pumps feature two-speed or variable speed operation
while others feature dual compressors to vary output capacity and match loads.
The Benefits Speak for Themselves
Tens of thousands of homes are being built or retrofitted with geothermal
heating and cooling systems every year, because of the advantages these systems
offer: economical operation, noise reduction, and product quality. Initially
reserved for the most expensive homes, now these systems have become affordable
options for thousands of low and moderate income housing units because of the
system's low life cycle costs compared to all other alternatives in almost
every region of the country.
Geothermal Heating and Cooling Makes
Sense
Geothermal systems are efficient,
environmentally-sensitive, comfortable, and economical. Operating savings often
provide paybacks of considerably less than five years -- sometimes less than
two years. In addition, electric utilities such as BGE are so convinced of the
value of this technology for their customers that they offer design assistance,
referrals, or financial incentives to defray the first cost increment of
geothermal systems.
The key is that geothermal heat pumps use electricity to move heat, not to
generate it by the burning fuel or using electric resistance elements. Indeed,
the U.S. EPA has found that no other technology with more favorable operating
efficiencies and economics than emerging geothermal heat and cooling systems.
An Important Renewable Energy
Technology
The U.S. Environmental Protection Agency has concluded that well-designed and
properly installed high efficiency geothermal heat pump systems produce less
environmental harm than any other alternative space conditioning technology
currently available. On a full fuel cycle basis, emerging geothermal systems
are the most efficient technology available, with the lowest CO2 emissions for
minimum greenhouse warming impact. Overall, the EPA found emerging geothermal
heating and cooling systems to have the lowest environmental cost of all
technologies analyzed -- including air-source heat pumps and natural gas
furnaces.
Geothermal Heat Pump Systems Work!
No existing space conditioning technology offers greater comfort, economy, or
environmental benefits than the geothermal heat and cooling systems now
available for residential and commercial installations. Over 250,000
installations are in place in the