Buried beneath Ellen and Alvey Horine's front yard in Pleasant Valley is a maze of copper coils designed to save money while helping heatand cool their house.
The Horines are the first in Carroll Countyto "turn dirt into dollars," as in the slogan used to tout a system called Ground Source Direct Exchange.
Only about 1,000 homes in the country have the system, which was invented nine years ago in Kansas City, Mo., according to the president of USPower Climate Control Inc., which owns the patent.
Earlierthis month, a 45-by-50-foot hole 5 feet deep was dug in the Horines'front yard. Workers from Modern Comfort Systems Inc. of Westminster laid 2,400 feet of copper coils, which were then filled with the samerefrigerant gas used in freezers and air conditioners, assistant manager Thomas Eckard said.
Ellen Horine said the digging attracted the neighbors' attention.
"I guess one thought we were putting a swimming pool in our front yard," she said.
In cold weather, the gases flow through the coils and transfer heat from the ground into the Horines' home. In warm weather, the system takes heat from the home and transfers it to the ground, said C. Nevin Haines, vice president and general manager of Modern Comfort.
The Horines had been paying $200 to $300 a month to heat and cool their home with an electric system, Ellen Horine said. With the new system, they expect their energybills will total less than $500 a year for their 2,200-square-foot ranch home, she said.
USPower says the system cuts customers' costsby 40 percent to 60 percent.
The system uses some electricity to run a compressor that blows the air into the house, said Jeffrey T. Aspacher, president of USPower, which is based in Allentown, Pa.
Officials at Baltimore Gas and Electric Co. are aware of the system andare looking into offering incentives for homeowners who install it, spokeswoman Peggy Mulloy said.
Aspacher said utilities in some states offer customers who install the system a one-time rebate. Pennsylvania Power and Light offers a rebate of about $750, he said.
Somestates also offer tax credits, he said. Maryland does not, an assistant state comptroller said.
Neither the federal government nor Carroll County offer tax credits for the system.
The Horines' system was turned on April 12.
Ellen Horine said they chose it because ofits efficiency and because it wouldn't force them to "be married to the oil company."
"I know 10 years down the road I won't have an increase in costs," she said.
The system is expensive to install --from $6,000 to $14,000, depending on the size of the home, which is about double the cost of a conventional system, Eckard said. Excavation and landscaping work are extra.
Horine said she expects the system to pay for itself in five to eight years.
Modern Comfort is the only authorized dealer for the new system in Carroll. Maryland has about a dozen dealers, Aspacher said.
The most popular system soldby Modern Comfort, a subsidiary of S. H. Tevis and Son Inc. of Westminster, is the more conventional air-to-air heat pump, he said.