CT Habitat For Humanity Home Tapping Into Geothermal Energy

Feb 14, 2014

Workers at the Habitat for Humanity home in Canaan, CT
Credit George Massey/Habitat for Humanity of Northwest CT

A Habitat for Humanity home in northwest Connecticut is undergoing some groundbreaking and ground-warming.

Though the Northeast has been put through an active winter, workers in Canaan, Conn. are not letting snow totals stand in their way. Instead, they’re drilling a hole 400 feet deep and 6 inches wide in order to extract heat from the granite rock below. The work is being carried out by the Connecticut Geothermal Association, a group of drillers, engineers and designers dedicated to promoting geothermal energy. Association member Peter Tavino is working on the project.

“Although it costs a little bit of money to put it in, your return on investment is very quick,” Tavino said. “As prices of gas and fuel oil go up, the price of geothermal never goes up.”

The system uses two 400-foot plastic pipes connected at the bottom of the hole by two 90-degree elbows, forming what’s called a geothermal bore hole with a U-bend pipe. A connecting pipe then runs underground from the hole to the basement of the house and is filled with water. Tavino says colder water from the house is pumped into the pipes and extracts heat from the warmer bedrock. The warmer water is then put in contact with a refrigerant. Added pressure raises the chemical’s temperature, which then gets put into a radiator coil.

“A blower fan circulates the air from the rooms against that 120-degree coil and that heats up the air so that when it comes out, it comes into the room at about 90-degrees,” Tavino explained. “Eventually the room can stay at 70-degrees.”

In the summertime, the process is simply reversed.

“Whether the ground is 50-degrees and we raise the temperature of the rock up to 55 or 60-degrees, it’s just rock,” Tavino pointed out. “It has no impact. We actually want to warm it up a little bit. We like to heat it in the summer so that in the winter it’s a little warmer and then we pull the heat out the next winter and then in the summer we put the heat back in. Sort of like a bank account, you deposit heat, you withdraw heat, you deposit heat and you withdraw heat, every six months.”

Carrying a retail value of about $40,000, the system was a gift from the Connecticut Geothermal Association to the Habitat for Humanity of Northwest CT. It will be utilized in a three bedroom, 2,100 square foot home built in the 1980s that hasn’t been lived in for a number of years. The Habitat’s George Massey says this is the first house the organization is not building from the ground up since it was founded in 1990.

“We do try to build green and we try to have well-insulated houses,” Massey said. “Affordability is a key word for us. We’re not only interested in the houses’ mortgage payments being affordable, but in it being affordable to live in the house.”

Tavino says the electricity costs to run the system are a quarter of what it would be to heat the home with electric heat. Massey says Habitat hopes to find a partner family over the next month.

“Part of what the partner does is put in 400 hours of his and his family’s labor into the construction,” Massey explained. “So we like to choose our family fairly early on in the project.”

Massey says the system’s benefits will continue for many years.

“When we have a homeowner that we partner with, we sell them the improvements, but we don’t sell them the land,” Massey said. “Our vision is, after their lifetime lease is over or they decide to sell whenever they want, we will buy the house and put it back to another Habitat family. So this donation is going to pay back and pay back and pay back to multiple families over the years.”