What Are Geothermal Heat Pumps?

Geothermal/Ground Source Heat Pump Diagram


Considered the gold standard of heat pumps, the advantages of geothermal are numerous: there is no "low temperature" rating on geothermal house heating systems, because the earth is a fairly constant temperature, and there are no above ground outside units to frost up, or to worry about keeping clear of snow or wind.

All geothermal systems are "central" systems, which means that the heat must hook into a central distribution system. (Mini split systems are "decentralized" systems, which mean that we need to connect the inside systems to the one or more rooms that will be heated by the inside unit, vs using a central heat distribution system).

Most typically this means using a new or existing forced hot air ducted system. Radiant heating systems are already a good match with geothermal systems using ground to water equipment.

Currently geothermal benefits from the same 30% federal tax credit that solar electricity does. That federal tax credit sunsets on December 31, 2016, just as it does for solar electric systems. There is also a state incentive of $5,000 from Efficiency Maine (subject to availability of funds, and can be pulled with little notice).

While the cost of operating is lower than mini-split systems, very often the payback is longer because of the higher upfront cost, even after incentives. That said, we love geothermal systems and would be happy to answer any questions that you have.