The percentage of homes in the United States with geothermal heating and cooling systems, which rely on the earth’s constant underground temperature of 45 to 75 degrees Fahrenheit to provide comfortable indoor climates, is small but growing fast. Geothermal systems are installed in about 50,000 new homes each year, according to the U.S. Department of Energy. And the U.S. Environmental Protection Agency (EPA) has declared geothermal the most energy efficient, environmentally clean and cost-effective space conditioning system available.
Geothermal systems use an underground network of pipes filled with water or refrigerant and a heat exchanger to pull heat from the ground and transfer it to the house in winter, then reversing the process and depositing heat from the house into the ground in summer. Natural Home & Garden featured a number of homes equipped with geothermal systems over the years, and I visited them in all seasons. They really are more comfortable than homes with mechanical blowers. And every one of the homeowners told me, as they showed off their systems, that they had seen pay-off in reduced electricity and gas needs.
Here’s a range of homes. This technology works in any size or style of home, in nearly any setting on earth.
Photo by Paul Warchol/Natural Home & Garden
John Petrarca, a pioneer who brought geothermal and many other green building elements to lower Manhattan, died in spring of 2003. Earlier that year, we featured the five-story, 6,000-square-foot home and office space that he and his wife, Sarah Bartlett, built in New York’s historic Tribeca neighborhood. The home, along with five others that John built in the neighborhood, had the first geothermal system in Manhattan. John’s application for an oil and gas well (required to drill the 8-inch hole for his pipes) caught the EPA’s attention, which proved to be a blessing. That agency enthusiastically supported John’s experiment and pushed through the application to get his wells approved. A noisy drilling rig with specialized steerable bits bored through 100 feet of dirt, then 1,100 feet of Manhattan schist before it hit its mark. John endured his neighbors’ wrath during the 28 days it took to drill a well for each of the five houses.
Carbon Neutral in the Windy City
Photo by Barry Rustin/Natural Home & Garden
Michael and Beth Yerke’s house in Chicago’s Lincoln Park has a cutting-edge energy infrastructure that earned it stripes as Chicago’s first entirely carbon-neutral, all-renewable-power home. David Dwyer, founder of American Renewable Energy, used multiple renewable energy sources and energy-efficient strategies to build the 4,500-square-foot home to Energy Star standards. A geothermal energy system with 22 loops of pipes that reach 80 feet into the earth, complemented by a solar thermal array, provides the home with forced-air space heating, radiant in-floor heating, air conditioning and hot water. The Yerkes expect the system to pay for itself within four to six years.
Easy, Breezy Greenies
Photo by Stephen Ang/Natural Home & Garden
Paul and Rabia Nagin’s 6,800-square-foot Energy Star-certified home northwest of Manhattan is heated and cooled by a geothermal system that relies on the near-constant 55 degree temperature. “It costs around $4 a day to heat this house, and it’s roughly three times the volume of the average house,” Paul says. He expects to recoup the geothermal system’s costs in four or five years.
Photo by Susan Sully/Natural Home & Garden
John and Sue Porretto’s timber frame home enclosed with structural insulated panels has a closed-loop geothermal heating and air conditioning system, in keeping with the light-on-the-land covenants in Dewees Island, South Carolina.
A Tiny Home
Photo By Dan Hoffman /Natural Home & Garden
Not all geothermal homes are as big and grand as the previous four. The 360-square-foot Experimental Dwelling for a Greener Environment in Bayfield, Wisconsin—Revelations Architects/Builders’s “pure vision of simple living”—also boasts geothermal heating and cooling. “We wanted to show that Americans could live well with less,” says Bill Yudchitz, Revelations Architects/Builders president. Only the necessities are included in this minimalist, energy-efficient home, and geothermal just made sense.