FAQ's
Parts of the system
The three main parts are:
- The heat-pump unit
- The liquid heat exchanger medium (open or closed loop)
- The air-delivery system (ductwork)
No. There are different kinds of geothermal heat pumps
designed for specific applications. Many geothermal heat pumps, for example,
are intended for use only with higher temperature ground water encountered
in open-loop systems. Others will operate at entering water temperatures
as low as 25 degrees F which are possible in closed-loop systems.
Most geothermal heat pumps provide summer air conditioning,
but a few brands are designed only for winter heating. Sometimes these heating-only
systems incorporate a groundwater cooled coil that can provide cooling in
moderate climates. Geothermal heat pumps can also differ in the way they
are designed. Self contained units combine the blower compressor, heat exchanger
and coil in a single cabinet. Split systems allow the coil to be added to
a forced-air furnace and utilize the existing blower.
Will I have to add insulation to my home if I install one of these
systems?
Geothermal heat pumps will reduce your heating and cooling
costs regardless of how well your home is insulated. However, insulating
and weatherizing are key factors in realizing the most savings from any
type of heating and cooling system.
Can a geothermal heat pump also heat water for my home?
Yes. Using what's called a desuperheater, some types
of geothermal heat pumps can save you up to 50 percent on your water heating
bill by preheating tank water. Desuperheaters are standard on some units,
optional on others. Some geothermal models can provide all of your water
needs on demand at the same high efficiencies as the heating cooling cycles.
Is a geothermal heat pump difficult to install?
Most units are easy to install, especially when they
are replacing another forcedair system. They can be installed in areas unsuitable
for fossil fuel furnaces because there is no combustion, thus, no need to
vent exhaust gases. Ductwork must be installed in homes that don't have
an existing air distribution system. The difficulty of installing ductwork
will vary and should be assessed by a contractor.
Can a geothermal heat pump be added to my fossil fuel furnace?
Split systems can easily be added to existing furnaces
for those wishing to have a dual-fuel heating system. Dual-Fuel systems
use the heat pump as the main heating source and a fossil fuel furnace as
a supplement in extremely cold weather if additional heat is needed.
I have ductwork, but will it work with this system?
In all probability, yes. Your installing contractor should
be able to determine ductwork requirements and any minor modifications,
if needed.
Do I need to increase the size of my electric service?
Geothermal heat pumps don't use large amounts of resistance
heat, so your existing service may be adequate. Generally, a 200-amp service
will have enough capacity, and smaller amp services may be large enough
in some cases. Your electric utility or contractor can determine your service
needs.
Should I buy a heat pump large enough to heat my home with no supplemental
heat?
Your contractor should provide a heating and cooling
load calculation (heat loss, heat gain) to guide your equipment selection.
Geothermal heat pumps are sized to meet your cooling requirements. Depending
on your heating needs, a geothermal heat pump will supply 80 to 100 percent
of your design heating load. Sizing the heat pump to handle your entire
heating needs may result in slightly lower heating costs, but the savings
may not offset the added cost of the larger heat-pump unit. Also, an oversized
unit can cause dehumidification problems in the cooling mode, resulting
in a loss of summer comfort.
Do geothermal heat pumps have outdoor units?
No. The equipment goes inside your home, usually in the
basement, garage or crawl space. Because it's indoors, the lifespan of the
compressor and major components are greatly extended, most having a lifespan
of 20 years or more.
