WYANDOTTE, MICH. — The principle behind geothermal heating and cooling is a simple one: dig down toward the bedrock almost anywhere in the world and you reach a stable temperature zone that is somewhere between 52°F and 55°F year-round. By using water circulated in a deep enough ground well as an energy transfer medium, you get the ∆T between well temperature and surface temperature — cooling power on hot days, heating power on cold ones — practically for free.
The obstacles to the practical use of geothermal power are chiefly the expense of digging wells deep enough and of the equipment needed to make use of that free energy. Wyandotte, a city with a population of just over 25,000 located in southern Michigan, is attempting to address both obstacles at once with the creation of a geothermal utility.
The plan, made possible in part through a $560,000 Neighborhood Stabilization Grant from the federal government, is an ambitious one. The project has identified 48 installations in the planning phase, and work has been either started or completed on 10. Included in the plan are 25 new residential installations, 19 retrofit installations, three commercial installations and one new 20-unit multi-family development.
The city hired private contractors to drill ground source wells in utility easements and connect several homes to each well. Tentative plans call for the municipal services to cover the $8,000 cost for each well and charge home and building owners a monthly service fee and energy charge based on the capacity of the system installed. On the other side of the equation, homeowners can qualify for a 30% tax credit on the cost of purchasing and installing a geothermal system through 2016.
The job of installing those systems went to Jeff Caplan’s firm, Cappy Heating & Air Conditioning, based in Livonia, Mich. Caplan, the owner and president, has been in the trades for nearly 30 years and sees geothermal work as a natural outgrowth of his regular HVAC service. Cappy Heating & A/C is accredited by the International Ground Source Heat Pump Association (IGSHPA). The company has about 32 employees, with a service area covering most of southeast Michigan.
After winning the bid, Cappy Heating began work in earnest last October.
“If it’s new construction there’s time to get in and do the rough portion, then go and do the ducts,” Caplan explained. “It’s usually a two-man crew and it can take 40 hours each man, so about a week, more or less.”
The renovation work can be even more involved with a lot needing to be torn down before the installation can begin. Cappy Heating begins its portion of the work after the well has already been drilled.
“The geothermal utility puts in the field portion, the drilling and the pipe,” Caplan said. “We pick it up from the geothermal utility stop box — it’s like a water box that’s out in the front yard — and pipe it into the home. And from there we supply and install the ground-source heat pump, then do all the sheet metal ductwork. We design and build all of that.”
Caplan decided to use the Envision series ground source heat pump from WaterFurnace. The appliance is available in seven single-speed sizes and five dual-capacity sizes to meet the needs of almost any application. It uses ozone-safe R-410A refrigerant, and features microprocessor controls. Correctly installed and maintained, it can deliver energy savings as high as 70% compared to more conventional heating and cooling systems, and can even supplement the domestic hot water supply.
“In addition to the savings,” Caplan said, “a geothermal system provides precise distribution of comfortable air all year long, eliminating hot and cold spots throughout the home.”
The systems emit no greenhouse gases and are exceptionally quiet.
Caplan sees the first phase of the plan at Wyandotte lasting another two to three years, with the hope that the approach becomes ongoing and self-sustaining.
“The idea is that the geothermal utility will be thought of like your water bill,” Caplan said. “They’re hoping that the whole community sees this as a good thing, and that other cities will join in… as new construction comes to the city, they give them incentives to go with geothermal.”
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