Anyone who has retreated to a cold basement on a hot day knows the concept is as old, quite literally, as the hills. Beneath the Earth's surface, the temperature is constant. By tapping that, homeowners with geothermal systems can cool their homes, or provide heat.
A geothermal system circulates a water solution through pipes that are buried beneath the home, yard or, if there is a body of water close by, underwater.
In the winter, the fluid carried by the system is warmer than surface air. In the summer, it is cooler. The home's ventilation system distributes air, warmed or cooled by the fluid, throughout the house.
A geothermal system costs more to install than a conventional heating/venting/air conditioning (HVAC) system, but pumping the warm/cool air through the house uses less electricity than does a typical heating or cooling system. So it can yield long-term energy savings which, in turn, can save money. The system doesn't burn fossil fuels, which makes it the right choice for many environmentalists.
Such systems "are more popular in some areas than in others," says Mike Bell, spokesman for the National Association of Home Builders' (NAHB) green building committee.
"Where they are used more often, there are more HVAC contractors who do them or utilities that encourage them through incentive programs."
This means geothermal systems are more prevalent in homes in Oklahoma, Texas, Wisconsin, New Hampshire and Colorado. In Illinois, "geothermal" is, at least on the residential side of real estate, largely still a foreign term outside "green" circles.
For Rita Angelini of Prospect Heights, the investment was worthwhile.
"My husband wanted to find out how to make this house energy-efficient long-term, so he learned about it," saysAngelini. She and her husband, Norman Riess, tore down the house they owned on the same lot and built their current house in 2005. Built to accommodate their disabled daughter, it has 5,000 square feet plus a room with an indoor therapy pool that is heated to 90 degrees year-round.
Angelini says their electric bill runs $500 a month.
"We can't compare that to our old, smaller house," she says. "But we can compare it to a friend's house that is half the size of ours and also has an indoor, heated pool, but costs $600 to $700 a month for a conventional HVAC system."
Before ComEd's recent price increases, Angelini had figured their payback period for the additional cost of the geothermal system would be five years. Now, she says, it will be longer.
"It is still worth it because we are staying in this house," says Angelini. "My daughter will live here for her lifetime. We'd do it again, despite the increase."
"For me, it was a no-brainer," says Doreen Schweitzer of Naperville, who installed a geothermal system in the 5000-square-foot house she built in 2006. "I feel a responsibility for our environment, and this is a greener way than using a furnace and air conditioner."
Schweitzer's last bill for electricity, which she buys from the city of Naperville, was $200 for two months. "That was during that hot weather this summer, and we were very comfortable," she says.
Schweitzer says she had initially figured it would take her seven to ten years to pay back the added cost of the geothermal system, but increased electrical rates will extend her payback period, she says.
"I'd still do it again," says Schweitzer.
To help cover the cost of a geothermal system, some homeowners employ "energy-efficient mortgages" (EEMs) that allow larger loans based anticipated lower utility bills. (The homeowner pays less money monthly for utilities, meaning he or she can afford more for his monthly mortgage bill.) For more information about this, visithttp://www.resnet.us .
Geothermal systems are more often chosen by high-end home buyers, says Bell. "Then, the buyer works with the architect and custom builder to choose green systems. At the production [home-building] end, the builder doesn't take the time or make the investment," he says.