Geothermal Loop Installations and Your Plumbing Business

One reason why more homes don’t use geothermal heat pumps is the cost. Although the systems may operate more efficiently than conventional HVAC systems, they are considerably more expensive to install. Another reason for their traditionally lower market share is familiarity: Putting in a geothermal heat pump is outside the norm for most HVAC installers, so the systems aren’t recommended as often as they otherwise might be.

Getting their attention
The lack of familiarity is relevant because the cost issues are fading away with the help of a federal government tax credit that offers a 30 percent discount with no upper limit for people who install geothermal heat pumps (also known as ground-source heat pumps). That decrease in cost differential has attracted homeowners’ attention. As they work on their taxes this year, homeowners are being asked by their accountants and tax preparation software programs whether they installed a geothermal heat pump in 2009. In response, homeowners are asking plumbers and builders about geothermal heating and cooling systems, and whether such a system would be a good idea for their home.

“This gives you another competitive option to offer your customers, in addition to your existing business lines,” says John Kelly, vice president of the Geothermal Heat Pump Consortium in Washington, D.C. “One of the driving factors in this industry is that customers are asking for it, so for a [plumbing] contractor it’s nice to have on the menu—particularly if your competitors don’t offer it.”

How it works
The idea behind geothermal heating and cooling systems is that they use the steady, moderate temperatures of the earth to insulate against above-ground temperature fluctuations. Instead of using electricity or natural gas to generate the energy needed to regulate the temperature of the liquid in an HVAC heat pump, geothermal systems route the liquid (water or an antifreeze solution) through a loop that often goes far below the surface where the temperature of the liquid is regulated by the even underground temperature. (Temperatures six feet below the surface range from 45 to 75 degrees Fahrenheit.)

There are several types of loops: open-loop systems, which use water from a well or pond to circulate through the system; closed-loop systems, which run the loop through a body of water instead of deep underground; horizontally oriented closed-loop systems, which run their loops a few feet below the surface but cover a lot of surface area; and vertically oriented closed-loop systems, where the loops may run several hundred feet down.

The vertical systems are both the most complicated and the most expensive to install because they require a licensed driller and a hammer drill. But particularly in urban environments where homeowners don’t own large lots, these systems often are the only viable option. Horizontal loop systems start at about $600 per ton of capacity, and vertical systems at about $1,500 per ton—the average house requires about three tons of capacity, according to Jim Bose, executive director of the International Ground Source Heat Pump Association in Stillwater, Okla. and an engineering professor at Oklahoma State University.  

Why go geo?
“If it’s new construction, geothermal is probably a no-brainer,” says Bose, whose organization offers training and accreditation for installers nationwide. “In the case of a retrofit, the question is, ‘How bad are the energy costs now? Are they eating you alive?’” His reasoning is based on the idea that in new construction, consumers could roll the cost of the system into their mortgage, and their monthly energy savings would exceed their additional cost. In the cast of a retrofit, the financing becomes trickier. In either case, the geothermal heat pump essentially replaces the home’s furnace and feeds into the ductwork.  

If a customer asks you whether it would be a good idea to install a geothermal heat pump, there’s no cut-and-dried correct answer. But, increasingly, when that customer asks whether you are capable and qualified to install the system, your answer should be yes.