Geothermal System Types

A geothermal system includes three principal components:

  • Geothermal earth connection
  • Geothermal heat pump subsystem
  • Geothermal heat distribution system

Earth Connection
Using the Earth as a heat source/sink, pipe or loops are installed in well(s) near the building to be conditioned. Water (water or a mixture of water and antifreeze in a closed loop system) is circulated and absorbs heat from, or relinquishes heat to, the surrounding soil, depending on whether the ambient air is colder or warmer than the soil.

Heat Pump
For heating, a geothermal heat pump removes the heat from the fluid in the earth connection, concentrates it, and then transfers it to the building. For cooling, the process is reversed.

Heat Distribution
Conventional ductwork is generally used to distribute heated or cooled air from the geothermal heat pump throughout the building.

Residential Hot Water

In addition to space conditioning, geothermal heat pumps can be used to provide domestic hot water when the system is operating. Many residential systems are now equipped with desuperheaters that transfer excess heat from the geothermal heat pump’s compressor to the house’s hot water tank. A desuperheater provides no hot water during the spring and fall when the geothermal heat pump system is not operating; however, because the geothermal heat pump is so much more efficient than other means of water heating, manufacturers are beginning to offer “full demand” systems that use a separate heat exchanger to meet all of a household’s hot water needs. These units cost-effectively provide hot water as quickly as any competing system.

There are four basic types of ground pipe/loop systems. Three of these—vertical, horizontal and pond/lake—are closed-loop systems. The fourth type of system is the open-loop option – standing column wells or reverse return wells. Which one of these is best depends on the climate, soil conditions, available land, and local installation costs at the site. All of these approaches can be used for residential and commercial building applications.

Standing Column Wells

Residential parcel sizes in New England are not as sizable as in other parts of the country. And waterfront parcels tend to be even smaller. Property size coupled with New England Geology makes the standing column well the best choice for most residential projects.

Advantages of a Standing Column Well over a closed loop system

  • More conducive to New England Geology
  • Highest geothermal efficiency rating
  • Lowest geothermal system installation cost
  • Lowest maintenance geothermal system
  • Least amount of land area required

At LBR Geothermal Services we have extensive experience in all vertical types of geothermal wells.