RECTOR, Pa. -- Hundreds of miles from the nearest hot spring and more than 1,000 miles from any good-sized geyser, Joe Minyon is boring deep into the ground to heat and cool his home.
Minyon is one of a growing, albeit still relatively small, number of people bypassing natural gas, propane and heating oil in favor of geothermal systems, which can save homeowners 25 percent to 65 percent in energy bills.
And they don't have to be anywhere near geothermal activity.
"It is the most energy-efficient system in the world," Minyon said during a recent tour of the 15,000-square-foot stone home he is building in Westmoreland County, about 50 miles west of Pittsburgh.
"This ... was a big chore because I was born and raised in an all natural gas area. No way was I going to change. But once I started, there was no turning back," he said.
Geothermal systems are basically electric-powered heat pumps connected to piping buried deep in the ground, laid on a lake bottom or run down a well.
Because the temperature below ground is fairly constant -- around 52 degrees in Pennsylvania -- geothermal energy is simple to tap. Water and biodegradable antifreeze circulate in underground pipes to harness that energy in heat pumps.
Similar to the way a refrigerator works, a geothermal heat pump wrings the warmth from the liquid in the pipe loop. In its cooling mode, the pump uses the same liquid to carry heat out of the home and into the earth.
In a field next to Minyon's castle-like home, workers laid plastic pipe filled with water and antifreeze into several rows of trenches, which then will be covered with dirt and landscaped.
Weeks before, workers already had drilled 14 4-inch diameter holes 160 feet deep in a semi-circle around the home and dropped in more pipe filled with the same water and antifreeze mixture. A typical 2,000-square-foot house would use only three or four holes.
The technology is called geothermal, but some say a better name is geoexchange or ground source because the word "thermal" is misleading.
"There's this connotation that this was a geyser, this was Old Faithful," said Forrest Heinrich of WaterFurnace International Inc., which manufactured the system in Minyon's new house. "We're not running nature's steam through a house; we're removing heat from the earth."
A 1993 study by the U.S. Environmental Protection Agency found that geothermal systems are the most energy-efficient, least polluting heating and cooling technology available today in most of the country.
An estimated 300,000 to 400,000 homes and other buildings have geothermal systems, according to the Washington-based Geothermal Heat Pump Consortium.
About 50,000 geothermal systems were sold last year, a 22 percent increase over the preceding year, according to the consortium.
Geothermal heat pumps cost almost double to install but up to two-thirds less to operate than electric baseboard heat or conventional fossil fuel furnaces and hot water heaters. The savings are smaller but also significant on air conditioning.
In Lancaster County, Pa., a geothermal system was installed in Neff Elementary School in the Manheim Township School District at a cost of $13.69 per square foot, less than conventional systems at the Reidenbough Elementary School built four years earlier.
Annual heating and cooling costs at Neff run about 75 cents per square foot compared to about $1.16 at Reidenbough, according to the consortium.
Heat pumps also are generally safer, steadier, quieter and less obtrusive than conventional systems, according to Heinrich and Minyon.
Yet they represent only 1 percent of all heating and cooling systems in this country, partly because of perceptions and a reluctance to change.
"This industry is being spread by word-of-mouth, which is a slow process at times," Heinrich added.
According to the Energy Information Administration of the U.S. Department of Energy, about half of all sales of geothermal systems in 1996 were in the South -- from Maryland to Texas. That interest is due to the high numbers of new homes being built there and the area's high demand on both heating and air conditioning, said Harvey Sachs, technical director of the consortium.
"When you're satisfying both those needs, that is when it becomes real cost efficient," he said.
The Midwest accounted for 25 percent of all sales in 1996 and the West the other 25 percent, according to the Department of Energy.
California has been slow to embrace geothermal heat, in part because the weather isn't severe enough, Sachs said. He predicted that in a few years, though, Californians will adapt geothermal systems for water, rather than space, heating.
Geothermal systems are relatively scarce in the Northeast, partly because of high electric rates, relatively low oil costs and low rates of new construction.
Sachs said sales of geothermal systems in established areas have picked up as manufacturers develop methods to minimize disturbance of the existing landscape.
"We have mature landscaping at our house in Virginia," he said. "You can imagine what my wife is going to do when I put mine in. But we'll just do it carefully."