A source of energy that comes from the ground: in winter it heats your home by drawing heat from the earth, and in summer it cools the house and strips out excess humidity. A geothermal system installation can cut what you pay for electric heating by up to 70%. Here is what it costs to get there, and what comes back.
How it works: Geothermal systems take advantage of the stability of the ground temperature. Underground pipes carry a fluid, heat energy transfers from the ground to the fluid and then to the geothermal unit in the home. Inside, that heat is distributed through a conventional duct system or a hydronic radiant system. The loops can be vertical or horizontal, are made of durable high-density polyethylene, and are buried in the earth or submerged in a lake or pond. Which type suits you depends on the size and configuration of your lot.
What it costs to install: Current estimates put a full residential installation in Quebec somewhere between $25,000 and $45,000, and the total divides into roughly three equal parts: drilling and the underground circuit, the interior equipment, and labour. Capacity is sized in tons, and a typical house needs about a 3-ton unit. Drilling depth depends on how much heat you need, a function of the size of the home and the quality of its insulation, and on soil conditions. If your home is heated with oil through a forced-air system, the ductwork is already in place and is often adequate for geothermal. Prices vary enough with lot, soil and system size that only a site visit produces a real number.
What it returns: A geothermal system delivers four to five units of heat for every unit of electricity it consumes, an efficiency of 400 to 500% against a maximum of about 97% for even the most sophisticated gas or hot-air generator. That gap is where the savings come from, and it is what earns the installation back over the years you spend in the home. Government rebates shorten that further. How that compares with an air-source unit is covered in conventional heat pump versus geothermal.
What else you get: No fossil fuel is burned, so there is no flame, no odour, no fire risk and no carbon monoxide. There is no noisy outdoor unit to disturb the yard. One compact unit heats, cools and can supply domestic hot water, and an optional multi-zone controller lets you vary the temperature room by room. Because the energy is renewable, the system emits no carbon dioxide or greenhouse gases in operation. An installation is often compared to planting 750 trees or taking two cars off the road.
Maintenance and lifespan: An indoor geothermal heat pump can last up to 25 years, against 13 to 15 for a conventional air conditioner or heat pump, and the underground circuit can hold up for 50. Upkeep is minimal: regular checks and a monthly filter change.
If you want to know what the numbers look like for your own house, talk to our specialists, or read how geothermal heat pumps work and what they save for the technical side.
