Jeff Green | Aug 13, 2009
Back to HomeFeature Article - August 13, 2009 Heating from the ground upBy Chava Field-Green
As we hear more and more about the state of our environment and Canada’s massive contribution to global pollution, and simultaneously more and more about the state of our economy, finding a balance can be difficult.
For Gary Giller and his wife Pam Woods of Sharbot Lake, doing their part was having Therm Aire of Kingston install a geothermal heating system, which will take heat from the lake, and will heat their home in the winter, cool their home in the summer and supplement their hot water heating system.
It takes a little while to wrap one’s head around the mechanics of geothermal heat, especially the idea of extracting heat from a frozen lake in the middle of winter to heat a house.
For the Giller/Woods’ system, a structure of five columns of coiled loops was placed at the bottom of Sharbot Lake. It is a closed lake loop system, which means there is a solution of 75% water and 25% ethanol anti-freeze that is constantly being pumped through the coils from the lake to the house and back again.
When it reaches the heat pump, through a pressure system like that of a refrigerator or an air conditioner, the heat is compressed from the water, which even in the winter is about 52°F.
The water being sent back into the system is about 8 degrees cooler. When it gets back to the lake it will absorb heat and become the same temperature as the environment outside of the pipe - in this case the water at the bottom of Sharbot Lake.
The heat extracted from the water moves to the furnace where it enters the air either via furnace ducts, or by hydronic in-floor piping, which heats the floor when hot water passes through the pipes under the floor.
In the summer, the system works the other way around, extracting heat from the house and sending all of the extra heat energy either back into the ground or to preheat water for the hot water heater.
For every one unit of electrical energy used to charge the heat pump furnace, up 4 units of heat energy is produced, depending on the difference between the air temperature inside the house and outside.
For the last week the Giller/Woods system has been installed piece by piece. The coils were set up at the boat launch at Oso beach on Wednesday. As technicians Doug MacKenzie and Joe Tremblay reinforced caging around the coils, pipe-fusion technicians Dan Wood and Darcy Warren fused together the last of the piping. The system was then towed slowly across the lake, against the wind, to Gary and Pam’s house.
“Everyone’s always looking for heat, but it’s always been right under their feet” said Danny Wood as they prepared to launch the structure into the water.
Therm Aire has been installing slowly evolving systems like this one for 20 years. They install other closed loop systems: the horizontal, which requires at least 300 m2 of land space for a series of loops, and the vertical loop, which sends loops down into the ground 15 to 100m deep. They also install open loop systems that take water from one well and distribute it into another well or pond in the same aquifer.
As far as costs go, Earth Energy Systems can cost anywhere from $20,000 to over $30,000 depending on the system, and the amount of work specific to your home, and the payback is dependent on your original heating costs.
For the next year and a half the costs will be partially supplemented by the government in the form of the eco-energy Retrofit house program federally and the Ontario home energy retrofit program. Both require an assessment by a Natural Resources Canada licenced advisor before and after the retrofit is done. For replacing another heating system with a geothermal system the maximum rebate offered is $3500 from each government.
For the remainder of the summer and this coming fall, Gary will be installing the ducts in his house himself, with recommendations from Therm Aire and the help of Steve Tarasick. This will help reduce the cost of the system.
“We’re really excited about this, and look forward to the system running,” Giller said.