GAMBIER — Kenyon College will use 20 geothermal wells to heat and cool its new art building, now in the first stages of construction.
“A geothermal well picks up the ground temperature and makes good use of it,” explained Thomas Lepley, director of facilities planning at Kenyon College. “It’s a constant temperature. Here in this area, it’s about 54.6 degrees. We drilled a test well to see what the conductivity of the soil was. You have to do that to see if it’s a match for the building.”
Lepley said the wells will maintain a constant temperature for which the equipment will be designed. Because the heat pumps and heat exchangers will be working with a constant temperature, he said, the equipment will operate much more efficiently.
Kenyon will utilize the geothermal heat pump system to make use of the wells.
That 54.6 degrees can be used to heat or cool the new facility. Fluid circulates through a series of pipes under the ground and into the building. An electric compressor and heat exchanger pulls the heat from the pipes and sends it via a duct system throughout the building, heating it in the winter.
In the summer, the process is reversed. The pipes draw heat away from the house and carry it to the ground or water outside, where it is absorbed. This is much like the way a window air conditioner works, pulling the heat out of the room, exhausting it to the outdoors and cooling the room inside.
One could, in theory, reverse the unit in the winter and have it pull heat from the outdoors and circulate it indoors. In the latter case, the air conditioner would have to work very hard because there is very little heat in the air during winter.
It is for this reason that the constant temperature of the geothermal well makes it more economical to use.
“What [the constant temperature] does is allows the heating equipment to be designed for that specific temperature,” Lepley said. “Conventional heat pumps, without geothermal, use air to air and, as you know, the air temperature changes dramatically from summer to winter. It’s just like an air conditioner compressor. But instead of having an air to air heat exchanger outside, our heat exchanger is underground.”
Lepley said this system is being considered for other buildings planned for construction in the near future. The current project consists of 54 wells drilled 400 feet deep, designed to serve just the new art building.
“The excavation for that building is just about complete,” Lepley said. “We’re seriously considering geothermal for the north dorm project, which is still in the planning stages.”
Lepley said the system could be added to existing buildings, although it is easier to do during the construction of a building.
“It’s the kind of thing I think the college will be glad it did now,” Lepley said. “Fuel, and therefore heating costs, never go down. Sometime in the future Kenyon will be glad they did this.”