Thos Swallow captures the sun's heat underground and pumps it through his little Salt Lake City bungalow, heating and cooling his home according to his mood and the weather.

The transformation began around Labor Day, when Comfort Tech crews used water to dig three 150-foot-deep, 4-inch-diameter bore holes in Swallow's backyard.

Four days later, a pump forced an 80 percent/20 percent mix of water and methanol through three loops of plastic tubing and transferred the heat into Swallow's basement geothermal converter.

Now he has no more excuses to avoid landscaping his deep lot. But he does have the deep satisfaction of knowing he has been a good steward of his 96-year-old brick home and its earth environment.

"I'm not like a super-crazy tree-hugger person," Swallow says. "But I try to help out."

Faced with replacing a worn-out furnace and clunky swamp cooler that chilled a small area near his back door, the 28-year-old computer programmer heeded a friend's advice and researched geothermal energy for home use.

He found Comfort Tech, an Orem heating and air-conditioning company that specializes in indoor comfort, geothermal heat sources and protection of the environment.

As company President Steve Lauritzen explains it, a pump housed in an exchanger, which looks a lot like a conventional furnace in Swallow's basement, draws the water-methanol mix through the tubal loops buried in the ground.

The ground at that depth, heated by the sun, maintains a steady temperature around 55 degrees Fahrenheit. The gathered heat is compressed in the exchanger and then runs through the house through its existing duct work.

In summer, the procedure reverses, with the exchanger taking the hot air from inside the home and pumping it into the ground. Some of the heat traveling in either direction routes through the water heater, helping to save on natural gas.

The pump requires a small amount of electricity, but the rest of the fuel is courtesy of nature. "In reality," Lauritzen says, "we're not tapping into ground heat, we're tapping into solar."

Becky Robbins, a Comfort Tech consultant, noted that solar-heating systems remain far more expensive than ground-heat exchangers, which have a quicker payoff.

The price tag for Swallow's 1,100-square-foot home on Blair Street between 300 East and 400 East and 1400 South? $23,000.

Gasp!

But here's the rest of the Comfort Tech arithmetic: Swallow's new heating and cooling system would get him $8,865 in federal and state tax credits; his annual heat, cooling and hot water cost of $753 would be nearly halved; so he could pay off his net $14,000 investment -- some $4,000 to $5,000 more than with a conventional furnace and cooler -- in 12 years.

Swallow acknowledges he probably won't still live in the house he's owned for five years come 2021. "I probably won't be here by the time the whole system pays itself off," he says, "but I will be here by the time I pay off the difference."

If that still seems crazy, remember that homeowners pay far more than $12,000 to remodel a kitchen or bath with far less a chance of getting a return on those investments, especially in this housing market.

And, speaking of the market, Swallow says his decision to install the systems "isn't entirely altruistic. I'm hoping it will add to the value of my home."