Canadians' heightened interest in environmentally-friendly energy efficiency has put previously-expensive heating alternatives in the spotlight. As fuel prices skyrocket, heat pumps are starting to make good financial sense.

An innovative geothermal heating and cooling system was a strategic feature in the energy retrofit undertaken at Bethany Manor in Saskatoon, Saskatchewan. This facility is owned and operated by a community-based non-profit organization comprised of 12 local Mennonite churches. Three hundred and twenty-five people live at Bethany Manor in a mix of 237 condominium, affordable living and assisted living apartments. A new 45-unit addition is planned for 2006.

Bethany Manor's geothermal system, a highly efficient and economical year-round system, is worth approximately C$1.1 million and it is expected to save about C$100,000 a year in utility and operational costs. The environmental impact in terms of greenhouse gas will mean a reduction of almost 3 million kilograms of carbon dioxide annually.

Conventional heating systems convert fuel to heat, but a heat pump is designed to move heat from one place to another. Even at relatively cold outdoor temperatures, a heat pump is able to extract heat from the earth to heat a building. In the summer, the system reverses the direction of heat movement to cool the building.

Saskatoon's Taylor Group of Companies undertook Bethany Manor's energy retrofit using a whole-building approach that focused improvement on four fronts:

• The florescent lighting was updated to T8 from the old T12 system.

   

• Controls were upgraded to direct digital controls.

   

• A Canadian-made solarwall , installed on a south-facing exterior wall at a cost of approximately C$125,000, was added to warm the fresh air brought into the facility. The Solarwall raises air temperatures 20°C (for instance, from minus 10° C to +10° C) without burning any fossil fuel. The payback is about 10 years.

   

• The biggest component of the retrofit was the installation of a geothermal heat pump system.

"The best thing is that [a geothermal heat pump] uses the earth's energy," said Randy Taylor, Regional Manager and owner of Taylor Group of Companies, based in Saskatoon and serving Western Canada. "If you have a furnace in your home or a boiler in your building, you need to burn fossil fuel and when you do, 10 to 15 per cent of that goes up the chimney. That's why we say 85 per cent efficient.

"If you heat with electricity, 1 unit of electricity can transfer to heat at a coefficient of performance of 1.0, that's approximately 100 times. With geothermal, the heat pumps run on electricity, so if you buy one unit of electrical energy you can extract another 2.5 units from the earth. That's 350 per cent efficiency and the coefficient is 3.5. The rising cost of electricity is an issue for the heat pump, but for each dollar purchased you get C$2.50 free. That's the exciting thing about geothermal heat pumps."

Other advantages include:

• No unsightly bulk of equipment beside the house or filling up the basement.

   

• No noisy compressor in the garden driving the air conditioning.

   

• No exhaust gases so there is no risk of carbon monoxide poisoning.

   

• Savings of over 50 per cent on heating costs compared with electric resistance heating (e.g. electric furnace), and up to 30 percent on air conditioning costs.

"The biggest reason they are not used is they [cost] about twice as much as a regular furnace and air conditioner," said Taylor. "In the past, we have had the luxury of reasonably cheap energy in Canada and now with rising costs it is more cost efficient to use geothermal."

Taylor practices what he preaches. He is removing his high-efficiency natural-gas furnace and installing a geothermal heat pump in his home. He expects to pay half his current utility costs and predicts payback in about 7 years.

Heat pumps fall into three categories that relate to the exchange mechanism:

• ground source

   

• water-to-water

   

• water-to-air (like air conditioners)

Ground source or geothermal heat pumps follow three design models, including closed loop, the system used in the Bethany Manor retrofit. Two hundred 4" diameter, 200- foot-deep holes were drilled in the courtyard. A 3/4" pipe went down each hole and up again, so that each hole had two pipes sticking out of it. A four-foot trench was dug between the rows of holes, the pipes were fusion welded together and then soil was back-hoed over everything. The heat pump is connected to the building and the ground loop filled with a methanol-water mixture that prevents freezing but circulates the heat -- from the ground to the building in the winter and from the building to the ground in summer.

Do your homework before signing on with a contractor. Although geothermal heat pumps are not a new idea, they are new to many contractors. Don't let them experiment with your property and your money. Look for experienced installers.

"One important thing is to make sure contractors you are dealing with are IGSHPA certified, that's the International Ground Source Heat Pump Association ," said Taylor, explaining that the three or four day course is essential to creating a successful heat pump. "The first step with heat pump installation is a heat-loss calculation for the building that will determine the size of the heat pump. If they are not designed properly, they will not work and that's where geothermal gets its bad name. If it's not installed properly, it won't work. When it is designed and installed properly, [a heat pump] will work for years."

To learn more about how heat pumps work, Taylor recommends the Canadian Earth Energy Society website