Low Energy Use
The biggest benefit of GHPs is that they use 25-50% less electricity than
conventional heating or cooling systems. This translates into a GHP using
one unit of electricity to move three units of heat from the earth. In
housing units that were all-electric in the pre-retrofit period, the GHPs
were found to save about 42% of the pre-retrofit electrical consumption for
heating, cooling, and water heating.
Free or Reduced-Cost Hot Water
Unlike any other heating and cooling system, a geothermal heat pump can
provide free hot water. A device called a "desuperheater"
transfers excess heat from the heat pump's compressor to the hot water tank.
In the summer, hot water is provided free; in the winter, water heating
costs are cut roughly in half.
While producing lower heating bills, geothermal heat pumps are quieter than
conventional systems and improve humidity control. These features help
explain why customer surveys regularly show high levels of user
satisfaction, usually well over 90 percent.
Geothermal heat pump systems allow for design flexibility and can be
installed in both new and retrofit situations. Because the hardware requires
less space than that needed by conventional HVAC systems, the equipment
rooms can be greatly scaled down in size, freeing space for productive use.
In my previous home, my GHP was placed in my
walk-in pantry. The entrance to the pantry acted as my return air so I
did not have an unattractive return air grill in my wall. I know that
many of you have seen, or may have in your home, a beautiful living room
with a 2 foot by 2 foot metal grill in the wall. A well planned GHP
installation can eliminate this.
Architects and building owners like the design flexibility offered by GHPs.
Historic buildings like the Oklahoma State Capital and some Williamsburg
structures use GHPs because they are easy to use in retrofit situations and
easy to conceal, as they don't require cooling towers.
GHP systems eliminate conventional rooftop
equipment, allowing for more aesthetically pleasing architectural designs
and roof lines. The lack of roof top penetrations also means less potential
for leaks and ongoing maintenance, and better roof warranties. In addition,
the aboveground components of a GHP system are inside the building,
sheltering the equipment both from weather-related damage and potential
Low Environmental Impact
Because a GHP system is so efficient, it uses a lot less energy to maintain
comfortable indoor temperatures. This means that less energy—often created
from burning fossil fuels—is needed to operate a GHP. According to the
EPA, geothermal heat pumps can reduce energy consumption—and corresponding
emissions—up to 44% compared to air-source heat pumps and up to 72%
compared to electric resistance heating with standard air-conditioning
According to a study completed for the Geothermal Heat Pump Consortium (GHPC),
buildings with GHP systems had average total maintenance costs ranging from
6 to 11 cents per square foot, or about one-third that of conventional
systems. Because the workhorse part of the system—the piping—is
underground or underwater, there is little maintenance required. Occasional
cleaning of the heat exchanger coils and regularly changing the air filters
are about all the work necessary to keep the system in good running order.
Zone Heating and Cooling
These systems provide excellent "zone" space conditioning. With
this, different areas of the building can be heated or cooled to different
temperatures simultaneously. For example, GHP systems can easily move heat
from computer rooms (which need constant cooling) to the perimeter walls for
winter heating in commercial buildings. School officials like the
flexibility of heating or cooling just auditoriums or gymnasiums for special
events—rather than the entire school.
Because GHP systems have relatively few moving parts, and because those
parts are sheltered inside a building, they are durable and highly reliable.
The underground piping often carries warranties of 25 to 50 years, and the
GHPs often last 20 years or more.
GHPs usually have no outdoor compressors or cooling towers, so the potential
for vandalism is eliminated.
To learn more
about GHP's and how they can drastically lower your home energy
Energy consultants Doug Rye and Phillip Rye show you how lower you
home energy usage GUARANTEED.
Heat Pump Systems
does a geothermal heat pump work?