Feeling the Heat

This season’s soaring fuel costs have many homeowners cringing when they open their utility bills. Owners of homes with new geothermal systems, however, are seeing the payoff for their investment in drastically reduced heating and cooling bills. “I had a client come back to me after a year and show me his utility bills that averaged about $50 per month,” says Patrick McDonell, owner of McDonell Construction in Hudson, Wisconsin. This owner would be paying closer to $450–$500 per month in a less energy-efficient, similar-sized home with a standard heating and cooling system. While McDonell is certainly not claiming that the entire savings is the result of a geothermal heating and cooling system, he does say that a fair share of it is due to the new technology. Typical utility savings for a 4,000-square-foot home range between 35 percent and 70 percent with a geothermal system.

Combined with other built-in, energy-saving options, the new geothermal systems are becoming a major player in green building in the metro area. “I think geothermal systems are becoming a definite trend,” says Jim McNulty, owner of McNulty Homes in Minneapolis. “Once customers become aware of the technology, they want us to pursue it for them.”

Geothermal heating and cooling systems use the constant temperature of the earth below the frost line, or about five feet down, to remove the excess heat in homes during summer and to heat homes in winter. Between five feet and about 1,000 feet, the ground temperature is at a constant year-round temperature of 50°F.

Horizontal Loops
There are two types of geothermal systems, horizontal loop and vertical loop.  “The piping that carries the water in a horizontal loop system is a coil that looks a bit like a slinky when you stretch it out,” says Larry Sharpe, project manager for McNulty Homes. The coil is buried at a depth of about eight feet. As water runs through this closed loop system, it is warmed to the temperature of the ground.

An electric heat pump then concentrates the water temperature to heat the house. The pump also has a reverse switch on it, which allows it to remove excess heat from the home in summer. The water in the geothermal piping, which has been warmed by the excess heat from the house, transfers the heat back to the earth.

The horizontal geothermal systems used by both McNulty Homes and Brandl Anderson Homes of Eagan require a fairly large geothermal field, or lot. For instance, Sharpe says a 3,000–4,000-square-foot home would require a lot space of seventy feet by seventy feet dedicated to the geothermal field.

Chris Brandl, part owner of Brandl Anderson Homes, says that while he is not installing many geothermal systems yet, he anticipates the number to increase as fuel costs rise and as the technology becomes more widely recognized. “The costs are pretty great up front. I’m trying to figure out a way to incorporate geothermal systems into affordable homes,” says Brandl, whose company builds homes in the $180,000 to $2 million price range. “I’m trying to figure out if we can make it work in a move-up home, say a $400,000 home,” he says.

Brandl has used the technology to heat an outdoor swimming pool of an upper-end home, and the cost savings have been phenomenal. “You pump water from the swimming pool through a plate heat exchanger that has been warmed by a horizontal geothermal loop system,” he explains. “You can heat a swimming pool for basically nothing,” when traditionally it costs about $600–$800 per month.

McNulty, who builds in the $850,000 range and up, says half of his clients choose geothermal systems and he believes that the systems will soon begin showing up in middle-range homes as well.

Vertical Loops
Geothermal technology has changed drastically, says Troy Hofmann with Family Homes in Woodbury. Years ago, he says, the tubing for the closed loop systems was not as reliable as it is today. The technology has improved so much that some suppliers of the tubing are now giving lifetime warranties that can be transferred to at least one other owner.

So far, Hofmann has built only one home in which a vertical geothermal system was installed, but he expects that number to pick up. “With the cost of the technology decreasing, fuel prices increasing, and technology improving, more people will see it as a more affordable option,” he adds.

McDonell also uses vertical systems, and in 2005, he put them in all of the upper-end homes that they built. Geothermal systems typically run $15,000 more than a standard heating system for a 4,000-square-foot home, the builders say. Prices can vary, though, depending on soil type.

KC Chermak, owner of Pillar Homes in Plymouth, is showing a geothermal home in Minnetonka with a vertical system in this year’s Spring Preview. Vertical systems require less land than horizontal systems, Chermak says, noting that a lot space of twenty by forty feet is adequate for a 5,000-square-foot home with a 2,000-square-foot foundation.

Chermak puts geothermal systems in about 25 percent of the homes he builds. “People asking about it are conscious of the environment, or savvy business people who know they can control costs,” he says. “Geothermal heating and cooling gives you ecological control of your house.”

Vertical system “wells,” or bore holes, which reach down to the water table but do not actually tap into it, are typically placed up to 180 feet deep. Closed-loop “wells” are then connected via a closed-loop system. Both vertical and horizontal loop systems can be covered by driveways, sidewalks, and patios. And while it is ideal to put the systems into homes when they are being built, homes can also be retrofitted with the technology. For a standard 4,000-square-foot home, about five “wells” are needed.

“The cooling surprises many homeowners, both in terms of cost savings and how well it cools the home,” Chermak says. Some energy suppliers have programs for geothermal that allow those who use the technology to buy off-peak electricity and gas for all their needs, sometimes at half the price of peak-use energy. On a house with a $500–$600 monthly utility bill, geothermal coupled with an off-peak program will typically cut utility costs by about 70 percent, says Chermak, making the payback for the system somewhere between six and nine years.

Other Options
Obviously, not everyone is ready for geothermal heating and cooling, and because it has a longer payback period than some of the other options, it doesn’t fit into every type of home. The system requires a back-up heating and cooling system, a storage tank, a heat pump, and either a vertical or horizontal loop system.

For instance, Brandl does not think geothermal systems will fit into starter homes anytime soon because most people do not plan on staying in the house long enough to make the investment pay off. “We don’t know what the resale value is yet,” he adds. “This is a new technology in our area.”

But other energy-saving options are available. “A lot of people are interested in high-efficiency furnaces and air conditioning units,” says Rick Hendel, owner of Hendel Homes in Wayzata. “People don’t hesitate to make that upgrade.” The payback on a high-efficiency heating and cooling system is only about three years, Hendel says, and the additional outlay is about $500–$800.

“Every house we have has some in-floor heat,” says Hendel. In-floor systems that use water as a conductor provide “a more consistent heat,” he adds, and typically require less energy to heat than floors warmed with electricity. In-floor heating systems can be heated by electricity, boilers, or geothermal systems.

Christian Warner, owner of Warner Building and Remodeling in Waconia, says his energy-saving system includes closed-cell spray insulation, in-floor heat, and ICF (insulated concrete form) construction in all basements. “The energy savings is phenomenal,” he says. According to Warner, ICF construction is used by fewer than 10 percent of builders in the area, and closed-cell spray insulation by fewer than 15 percent.

Remember McDonell, whose client’s utility bill was averaging $50 per month? Well, all of the homes he builds are 100 percent ICF construction and all have a geothermal system, with the primary heating source in the floor. “We make a very airtight home where we aren’t going to lose any energy,” he adds.

According to all of the builders we spoke to, energy-saving windows are now standard in new homes and geothermal systems are the newest and most exciting development in green building. “Geothermal is a smart decision for my clients,” says McDonell. “I want them to be in the most energy-efficient home they can be in.”

Christian Builders Unveils Health House Neighborhood By Barb Jacobs After completing their first Health House last year, Christian Builders of Rogers decided to take the next step and build an entire neighborhood of twenty-nine Health Houses in the Dayton development in the Twin Cities. Initiated by the American Lung Association, the Health House program sets strict standards for building techniques, materials, and testing to ensure a healthy, safe, durable, and energy-efficient home. According to their land and contract manager, Gretchen Hempel, Christian Builders will be the second builder in the nation to build an entire Health House project. For Christian Builders, this is not a huge leap-they have always been committed to energy-efficiency, and have won numerous awards in this category. Since last summer, Christian Builders has been building all of their homes to the Energy Star rating, a stringent set of guidelines that results in 15% less energy use than Minnesota's standard energy codes. In addition, all of Christian Builders’ homes are third-party tested to ensure that they meet the standards they are striving towards. While Christian Builders was focusing on the interior environments in the Dayton development, Patrick Dewing, the developer of the neighborhood, focused on its outside health. A fifty-acre wildlife sanctuary surrounds the development, which Hempel describes as a synergistic. “The Health House thing just kind of tied right into it,” she says.