I suppose that since coal heating, biomass, and pellet stoves have each enjoyed their own post, it’s certainly worth discussing the cleanest, most efficient way to heat and cool your home: Geothermal heat pumps.
Geothermal heating technology is hardly new. Buildings in downtown Boise, Idaho, for example, have been heated with water piped in from nearby hot springs since the 1890s. Over the next century, the geothermal energy industry grew…barely at all. Yes, geothermal energy is clean and sustainable, but that didn’t matter in a world where fossil fuels were cheap and plentiful and the pollution they created was largely ignored. Of course, that’s not the world we live in anymore, and over the past decade increasing numbers of homeowners have opted for clean and efficient geothermal heat pumps to heat and cool their homes.
How Geothermal Heat Pumps Work
Geothermal heat pumps use the heat at the Earth’s core to heat and cool buildings with water-filled pipes installed anywhere from six feet to hundreds of feet underground. These systems don’t bore down deep enough to where temperatures are extreme. In fact, they only go down to where the temperature is stable–and moderate. The water-filled pipes connect to a heat exchanger which, in effect, imports the moderate, comfortable temperature underground into your home. In winter, this means pumping subterranean heat into your house. In summer, it does the opposite, pulling the heat out of your home and sending it underground. Some systems also use waste heat to provide hot water.
Is it Worth Making the Change?
Geothermal heat pumps have numerous advantages over other types of HVAC systems. Most notably, they use 40 to 70 percent less energy with no carbon dioxide emissions or other pollutants, so they are the greenest of the green heating and cooling options. Once installed, they are also the most efficient, resulting in dramatically lower heating and cooling bills. Over the life of the system, they are also the least expensive. And, thanks to the recently passed stimulus bill, installing a geothermal heat pump at your home can cost less than you might think.
The sticking point for most people is the cost. A geothermal heat pump, including the cost of installation, can run well over $10,000, quite a bit more than a conventional HVAC system. Thanks to energy efficiency provisions that were included in the recently enacted stimulus bill, 30 percent of that investment comes back in the form of a tax credit. And if you can afford the initial outlay, making the change is definitely worthwhile. According to a report by the U.S. Department of Energy, the lifetime cost of a geothermal heat pump system, which includes installation and operating costs, is $5,000 to $23,000 less than other HVAC systems.
Find photos of different types of geothermal heat pump systems at the U.S. Dept of Energy’s Website.