Peter Blackie is uniquely positioned in three ways: He’s project architect for the new Creighton Street house he’s planning to move into later this year. Secondly, the site couldn’t be any closer to work; it’s a stone’s throw from the window of his office at MacKay-Lyons Sweetapple Architects. And his might be the first geothermal-heated house in Halifax.
“I’ve been working here for three and a half years and none of the residential projects our office has worked on have been geothermal; alternate power sources, yes, but not geothermal heating and cooling,” says the architect, who’s spearheading the endeavour along with Doug Weatherbee.
Weatherbee and Blackie will be neighbours in the row of four townhouses, all geothermal, designed and currently being built by MacKay-Lyons Sweetapple. “It just seems like the right thing to do,” says Weatherbee. “My wife and I, we look around at an awful lot of building going on, and we wonder, ‘What are these buildings going to look like in 10, in 30 years? And how are we going to heat them?’ It sounds cliche, but you must be the change you want to see in the world.”
Geothermal systems operate on the same principle as the household refrigerator, where a compressor and heat exchanger draw heat out of a fridge and shed it through rear coils. A heat pump draws fluid through a pipe run strategically underground just below the frost line, where the earth’s temperature is constantly warm, and up into the building, where the energy—which we experience as either heat or coolness, depending on the time of year—is distributed through ductwork or radiators, including the in-floor radiant heat Weatherbee and Blackie are planning.
The underground system can be either a closed loop containing anti-freeze, or an open loop that uses a groundwater source. The pipe, which may be copper or flexible plastic, either runs vertically through holes bored into the ground—as with the Creighton townhouses—or lays horizontally, like a slinky toy stretched out in an underground bed.
“It looked like we were installing a swimming pool five or six feet deep,” says Glen Atwood, who had a system installed in his Yarmouth house after he retired there 12 years ago. “Into that, we laid about 5,000 feet of pipe, slinky-style.”
The indoor pump, which should last 50 years because it’s protected from the elements, is smaller than a conventional furnace. And, because it isn’t oil-fired—generally, it’s electric—it’s both sustainable and cheaper to operate than conventional systems. Geoexchange systems are not completely unheard of here: Since Purdy’s Wharf was built in 1989, it has run its cooling system most of the year with ocean water. But very few, if any, Halifax buildings run geothermal heating systems.
Blackie readily admits that the price is high. “The geothermal system will about double the cost of our heating and cooling system,” he says, but he’s confident they’ll make it all back.
Atwood says he recouped his investment quickly: “You’ll spend as much as $10,000 more than what the fuel company would have charged to install a regular furnace with a long-term contract. So the question for me was: ‘What is the payback period?’ I thought at the time I would see my money back in eight years. But with escalating fuel costs, I made it back in less than five years.”
Add in the environmental impact: one geothermal system is equivalent to getting two cars off the road, according to the Geothermal Heat Pump Consortium in Washington, DC. Graham also cites environmental concerns: “At one point if you spilled a tank of oil in your house, it wasn’t a big deal; now, it’s a $200,000 clean-up.”
Blackie has a more positive spin: “It’s a minimum amount of effort. Any waste heat gets recycled back into the ground, and it’s all available without having to burn fossil fuels.”
He hopes the geothermal townhouses will also have an aesthetic impact in what he calls an “edgy” neighbourhood: “My wife and I bought into the area when we’d just come back from New York, where we lived in an old brownstone. We really wanted that exact sort of thing here. And we’ve discovered there’s a contingent here committed to high design, to architecturally designed buildings and doing things differently. Typically you end up spending more for that.”