Q: How does it work?
A: Geothermal heat pumps take advantage of the earth’s constant
temperature to provide efficient heating and cooling. A few feet beneath the earth’s
surface, the temperature of the ground remains fairly stable year-round, ranging
from 45◦F (northern latitudes) to 70◦F (deep south). Like a cave, this ground temperature
is warmer than the air above it during the winter and cooler than the air during
the summer. Geothermal heat pumps take advantage of these conditions by exchanging
heat with the earth. This allows the GHP to heat, cool, and if so equipped, supply
the home with hot water.
A GHP system collects the earth’s natural heat through a fluid-filled series or
loop of pipes made of copper or plastic that is installed below the surface of the
ground. The pipes can also be submersed in a body of water such as a lake or pond.
Fluid circulating in the pipes carries the earth’s heat to the home. In the winter,
an electric compressor and heat exchanger concentrates the earth’s heat and releases
it into the home at a higher temperature and then distributes it through ductwork
or pipes. In the summer, the process is reversed so that excess heat is drawn from
the home, expelled to the pipes and absorbed by the earth.
Geothermal heat pumps are efficient because they are using electricity to remove
heat from the ground rather than converting electricity directly to heat. During
the summer, geothermal heat pumps take advantage of the cool earth to provide efficient
air conditioning. Geothermal heat pumps can also use the waste heat from air conditioning
to provide “free” hot water heating in the summer.
Q: What are the benefits?
A: Because geothermal systems do not rely on fossil fuels to operate,
they do not rely upon combustion. Therefore, there are no direct emissions, fuel
tanks, or chimneys. With few moving parts, these systems are reliable and have low
maintenance costs.
Q: How expensive are geothermal systems?
A: Geothermal Heat Pumps have a higher installed cost compare to
traditional systems due to the ground coupling. However, the low-operating cost
can save money over the life of the system.
Q: Do geothermal systems provide free heating? How much can I expect to save
with a geothermal system?
A: Geothermal systems do not provide free heat. Rather, they use
electricity to operate single or multiple pumps, fans and compressors. Depending
on the size and design of the system, the electricity consumption can be significant.
However, since the systems are taking advantage of the earth’s constant temperature,
they are an efficient heating system and may save anywhere from 20 percent to 70
percent compared to a conventional heating and cooling system.
Q: Are they safe?
A: Geothermal systems are extremely safe. There isn’t any exposed
outdoor equipment, and geothermal units do not rely on combustion so there isn’t
a need for fuel tanks or gas lines.
Q: How quiet are geothermal units?
A: Units are extremely quiet. Since there isn’t any visible outdoor
equipment, outdoor activities are not disrupted by the cycling of a fan.
Q: How is heat transferred between the ground and the home?
A: The most common type of geothermal system relies upon a closed
loop which circulates fluid or refrigerant through the ground. These fields are
either vertical and/or consist of horizontal trenches, and can run several hundred
feet or more.
Q: Does it only provide heat?
A: Geothermal Heat Pumps have the ability to provide both heating
and cooling with the simple flick of a switch on the indoor thermostat. In winter,
heat pumps extract heat from the ground and distribute it throughout the home. In
summer, the process is reversed and heated air is drawn from the home and allowed
to be absorbed into the ground.
Q: How can I find out more about the rebates?
A: Additional information is also available on the Connecticut Clean Energy Fund website.