Q: How efficient are geothermal heat pump systems?
A: Actual efficiencies will depend on a number of factors, but generally a geothermal heat pump can be three to five times more efficient at providing heat than a gas, propane or oil furnace based on the amount of energy consumed to provide a given amount of heat. For cooling, a geothermal system is generally 30-50% more efficient than an air conditioner or heat pump.
Q: Why are geothermal heat pumps so efficient?
A: Geothermal heat pumps use the ground temperatures as a “source” for heat energy during heating and use the ground as a heat “sink” during cooling. The earth acts as a giant, free-energy battery, providing an endless, renewable source for heating and cooling comfort. Standard heat pumps use the outdoor air for heating and cooling. But because the ground temperature is much more moderate and stable than air temperatures, geothermal system operation is much more energy-efficient, especially at extreme outdoor temperatures.
Q: Can a geothermal unit be combined with a gas or propane furnace?
A: Yes. Some homeowners like the benefits of both technologies. In this case, a geothermal “split” unit (compressor only) is connected to a furnace and cooling coil. The geothermal unit will perform all the cooling and some of the heating. During the coldest days, the system switches over to a furnace operation. This type of system may be a good choice for a replacement installation.
Q: Can the existing duct work and electrical service be used?
A: Generally, the existing duct work can be used with a geothermal unit without extensive modification. Variable speed blowers used in many of the Bryant geothermal units can compensate for a less-than-optimum duct system. For the electrical supply, a 200-amp service for the home is recommended.
Q: What about radiant floor heating?
A: A geothermal system can be designed to provide warm water for radiant floor applications. Bryant’s water-to-water geothermal units are four to five times more efficient than today’s best boilers.