Heritage Restoration, Inc.

Geothermal Heating

My husband & I live in an 1809 house, with a commercial steam heating system. My dream would be to replace it with a ground source heat pump, since we have wells/cisterns on the premises and they could provide access to 50 degree cooling depths without drilling, I think. Also, our oil bills are astronomical and it would be great to have a more affordable system.

Some questions: Is it possible to make that kind of change in heating systems? Will ground source heat pump systems work in RI’s cold winters?


I appreciate your interest in a ground source heat pump, or geothermal system. There are many factors that determine if a geothermal system can work for you. Many facilities, businesses and homeowners have used this system effectively in the region, although there can be several obstacles to using it. The first, and most concerning for most, is the initial cost. Drilling and setting the systems can be very costly, even though the benefits can be great over the long term. An existing well may not be able to be used, since you have to install piping loops at specific lengths.

The second is then switching your system and retrofitting your house to a new central, forced air system. The house may or may not be a good candidate for a forced air system. We have installed high velocity forced air systems in two early houses, 1723 and 1810, with great success. In those cases we used natural gas powered boilers, and outside traditional outdoor AC compressors for one of them. The high velocity systems were used since the first floor was accessed from below, and the second floor was accessed from above. We also delivered the air from the easiest and most convenient spots, which ideally are where the principle air loss was on the exterior walls. Yet with some areas of inaccessible we had to try to push the air across the room, and mix it properly, hence using the high velocity. The systems blow about as hard as a high dryer, and can be quiet as long as the ducts are installed properly.

The third is you want to provide both heat and air conditioning to get the full benefits of the geothermal system. Since the earth is about 55 degrees, give or take a few degrees, you get a real benefit from using the temperature to cool your house in the summer. I would not suggest a geothermal system without using it as a cooling system as well.

The last, and perhaps the most important consideration, is your air leakage and heat loss/gain (depending on the season). The higher your air flow and greater the loss/gain the greater the load you need to heat and cool. In the 1810 house, we did replace all of the storm windows (keeping the old restored single panes windows), and insulated the basement. The attic was not accessible since it was finished. Reducing the airflow with storm windows and insulation, we were able to reduce the load significantly. The plank frame 1723 house was a bit more of a challenge. We did not have the ability to insulate the walls, basement or attic due to the house’s construction, budget restrictions, and the fact our intent was to save the original features of the house. In that case the load was higher, so we compensated with a larger system.

So the answer is yes, you can do it. But you may want to consider all of the factors of cost, heating/cooling load, and your long-term goals to determine what is best for you and most importantly, your house.

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