Installing geothermal heat pumps
Tue, Apr 14, 2009 at 03:13 PM
Illustration: U.S. Dept. of Energy
Q. I'm interested in installing a geothermal heat pump in my home—what exactly is it (in layman’s terms!), how much will it cost, and how do I start? – Lisa, Rhode Island
A. Before we tell you how to get started on geothermal, Lisa, answer us this: what do George Dubya and Ani DiFranco have in common? GEOTHERMAL. No lie, they both tap into earth’s stable core temperature in order to heat and cool their homes without harming the planet. Dubya is not, however, thirty-two flavors and then some, so that’s maybe where the two are different.
Geothermal heat pumps, sometimes called ground source heat pumps (GHPs) function like your standard heat pump, except that instead of taking power from the grid, they reach into the consistently 60oF earth for energy. Water or air pumped through pipes buried underground is then routed into the home or building, to cool it in summer and heat it in winter. GHPs are extremely energy efficient, and boast lower life-cycle costs and fewer environmental impacts than almost any other system. Ninety-five percent of current GHP users recommend them to family and friends, and the systems can be installed anywhere.
So, why aren’t they installed everywhere? For one thing, people aren’t used to the idea quite yet (what-o-thermal heat pump?). Another reason GHPs aren’t as prevalent yet as they could or should be is that the technology involves a pretty high upfront cost. But as energy prices rise, people like you are starting to weigh the long-term benefits (economic and environmental) against the upfront costs, and the industry is growing quickly. In fact, about 40,000 new pumps are installed each year, in our good old U.S. of A.
To get started, check out the International Ground Source Heat Pump Association, as well as the Geothermal Heat Pump Consortium. The Geo-Heat Center’s “Information Survival Kit for the Prospective Geothermal Heat Pump Owner” offers a comprehensive introduction to GHP, and the Department of Energy “Consumer’s Guide” breaks the technology down by type: closed loop vertical, closed loop horizon, open loop, and so on. Got a handle on how it all works? Now get in touch with an installer—or several, actually; multiple bids can foster competition and help lower the cost of installation. And ask prospective firms to supply names and contact info from completed projects—any quality installer should be happy to supply this information, so that you can check their creds. This upfront work will be time well spent—a good installer can save major headaches down the road. Happy digging.
Story by Alyssa Kagel. This article originally appeared in "Plenty" in April 2008.