innovate arkansas

In the last decade, electricity costs per kilowatt climbed 36 percent while the cost of natural gas about doubled based on a sample of 80 cities, according to the U.S. Department of Labor's Bureau of Labor Statistics.

In 2001, Dan Bandimere was between jobs and, feeling the weight of the rising prices, began to research alternative ways to heat and cool a house. When he happened across the geothermal method, he was hooked. He is now president of EnviroGuard Technologies LLC of Fort Smith and is booked solid with installations for the next three months. So far, Bandimere has installed from 150 to 175 commercial and residential systems in Arkansas.

Direct exchange geothermal heating and cooling, or geo-exchange, is a waterless system that involves drilling four 100-foot-deep holes into the ground within five feet of a house. The holes are two-and-a-half inches in diameter and confined to a 5-SF area. A film forms naturally over the copper tubes that are inserted into the holes, protecting them from corrosion.

The method is not to be confused with tapping into steam reservoirs, Bandimere said, since geo-exchange does not require large and heavy equipment.

Bandimere has easily tapped into the retrofit market because a geo-exchange system requires only a drilling machine about the size of a forklift and can be installed without seriously damaging a yard. The entire system can be installed in a day or two.

How It Works

Ground temperatures, even during a sweltering Arkansas summer or a suddenly frigid winter, remain fairly constant 5 to 7 feet below the surface. In the summer, geo-exchange pulls the hot air out of the house, stores it in the ground and "superheats" it over a period of about five months, Bandimere said. In the winter, the refrigerant in the copper pipes extracts the heat from the ground and blows it back into the house. Because the ground temperature is constant, the compressor on a geo-exchange system doesn't have to work as hard as the compressor on a standard air-conditioner.

"Generally, ground source heat pumps are much more efficient than air source heat pumps due to the stable nature of the heat source," Ray Fortuna, technology manager for the office of geothermal technologies at the U.S. Department of Energy, said in an e-mail response to Arkansas Business. He said that they are better for the environment because they don't need to generate as much electricity.

For a 2,500-SF house, which is the smallest size for which ground-source heat pumps are economically feasible, a homeowner can expect to pay about $23,000 for the whole package, including installation. But a geo-exchange system is about three times more effective than a standard air-conditioner, Bandimere said. He estimated that the system pays for itself in energy savings after five to six years.

A year ago, David Burton built a 7,000-SF home in Fort Smith and had a geo-exchange system installed. His previous house, he said, was a third the size of his new one and yet the two have similar electric bills.

While the system can eventually alleviate some pressure on the pocketbook, it can also ease environmental strain. Since the direct exchange heating system, even for hot water, is not a process of combustion, natural gas is removed from the equation. This cuts a homeowner's carbon footprint in half, Bandimere said.

Bandimere is not the only one who recognizes the importance of environmentally friendly home improvements. Some banks offer an Energy Efficient Mortgage option to customers through which they can increase their home loan to cover energy improve-ments.

The EEM program requires that a Home Energy Rating System report be conducted to assess the cost, annual savings and useful life of improvements and make suggestions for other cost-effective energy upgrades. The HERS report usually costs about $100 to $300. Bandimere, who is a trained energy rater, will perform the service free.

EnviroGuard Technologies, however, is about more than just heating and cooling homes. Bandimere contends that the "energy shell" of a house is just as crucial to green home management. EnviroGuard offers Nudura brand insulated concrete forms that use cellulose insulation, which is a recycled product.

With continuously rising energy costs and the ever-swelling carbon footprint of Americans, geothermal is a system Arkansans "need to take a real hard look at," Bandimere said.