Geothermal Heat Pumps: How it Works

With heating oil our primary heating source, it was clear an alternative was needed, and for better or worse, we got geothermal heat pumps. There are a few on the market now, and the technology is getting better. At the time of purchase, I knew of two companies: Water Furnace and Climatemaster. Since then, I've learned that Trane also makes heat pumps, but they are listed under their commercial section and not the residential section of their website.

How Geothermal Works

There are good write-ups on how heat pumps work on both the Climatemaster and the WaterFurnace websites. From Climatemaster:

The earth absorbs almost 50% of all solar energy and remains a nearly constant temperature of 50°F to 70°F depending on geographic location. Working with an underground loop system, a ClimateMaster geothermal unit utilizes this constant temperature to exchange energy between your home and the earth as needed for heating and cooling.

In winter, water circulating inside a sealed loop absorbs heat from the earth and carries it to the unit. Here it is compressed to a higher temperature and sent as warm air to your indoor system for distribution throughout your home.

In the summer, the system reverses and expels heat from your home to the cooler earth via the loop system. This heat exchange process is not only natural, but is a truly ingenious and highly efficient way to create a comfortable climate in your house.

Another more detailed explanation can be found on the WaterFurnace page here.

Getting Quotes

At the company's websites, there are dealer locator links, and we used those to get quotes from local installers. There is a story there and some lessons (next post).