The word “geothermal “is derived from two Greek words: “ge” meaning earth and “therme” meaning heat or warmth. And, in a way, that sums it up rather nicely, because the earth is warm and it is this warmth that makes geothermal systems work. In fact, in the Northeast, the temperature of the earth 6 to 10 feet below the surface is about 55°f year round. Geothermal systems take advantage of the difference between this 55°f temperature and the temperature in your house.

Geothermal Energy - Power from the Earth

Leaving aside the details of plumbing, HVAC and wiring , a geothermal system consists of a heat pump(s), fans and a network of pipes 6 to 10 feet under the earth’s surface that contain either water or an antifreeze-like solution or a combination of both. For cooling purposes, e.g. in summer, think of this system as a giant refrigerator with the door open and its fans running full blast. It sucks in the hot air from your house and transfers the heat in the air to the liquid in the coils behind the refrigerator; only in this case the coils on the back are buried in the ground outside. And they’re enormous. As the heated liquid passes through the coils buried in the cool earth, the heat is dispersed into the ground. Hot air is being drawn out of your house and put into the ground. As the liquid returns, now cooler, more heat is transferred and sent into the ground. As an added benefit, this heat can be sent to your water heater instead of into the ground. After all, you need hot water and the earth is doing just fine without the added heat.

In winter, when it’s cold outside, a geothermal system operates in reverse. The liquid in its pipes is heated by the earth and that heat is then extracted by the heat pumps to heat the air flowing into your ductwork. It’s a pretty simple idea, although a geothermal installation requires considerable expertise if it’s to be done properly.

It is likely that users of geothermal will reduce their heating costs 40% to 70% and cooling costs 20% to 50% when compared to conventional systems. To find out more, e-mail us at