Drawing heat from the ground is gaining interest among energy-conscious homeowners.

The answer to high heating costs could be in your own backyard. There is a better way, a greener way, to stay warm in winter and cool in summer while having a minimum impact on the environment: geothermal energy systems. People who have already made the switch to geothermal heating are singing its praises.

"We just got in under the wire," says Barb Smith of Amherst, NS. She and husband Graham installed a geothermal heating system in 2005 when oil prices were lower, and consider themselves lucky to have escaped subsequent high heating costs. With a nice-sized lot of 1.7 acres and a woodlot, their home was once heated with a wood/oil-combination furnace. But as they got older and Graham developed health problems, they knew they had to make changes.

They were introduced to geothermal heating at a home show and thought it was just what they needed. "We wouldn't have to worry about cutting wood, hauling wood or cleaning out ashes," Barb says.

Geoexchange systems, also called earth-energy systems and ground-source heat pumps, are based on the principle that the ground below the frost line is always the same temperature: 11°C to 12°C in this part of the country. While that's not warm enough to heat homes in winter, a heat pump, which runs on electricity, will collect heat from fluid that has circulated through the system.

A heat pump works on the same principle as the household refrigerator, explains Mark McCormick of Advanced Heating Solutions in Springhill, NS. A fridge absorbs heat from the unit and transfers it to the coils at the back of the fridge, which dissipates the heat into the room. A geothermal system, like a refrigerator, absorbs heat from the ground and transfers it into the home to be distributed. It works as a cooling system as well, absorbing heat from the building and transferring it to the ground. By lowering the temperature on the thermostat, the heating system becomes an air-conditioning system.

"We love it," Barb says. "We don't have to worry about a thing and we even have air conditioning in the summer." Barb says she would advise anyone to go for it.

Geothermal systems can be installed as open loop, using water directly from a well, or closed loop, where plastic piping is buried in the ground either in vertically drilled holes or horizontally in excavated trenches.

The open loop system uses two wells. Water is drawn from one well and sent to the heat pump, which concentrates the heat in the water and warms the home. The cooler water is then returned to the ground via the second well.

The pipes in a closed loop system are filled with an antifreeze solution and then sealed. The solution is circulated through the plastic pipe, where it absorbs heat from the ground. It then goes through the heat pump, where heat is extracted, then returns to the piping to repeat the cycle. The heat is distributed throughout the home using either a forced-air system or in-floor heating.

Since their wood/oil furnace was hot air, the Smiths were able to use existing ductwork and added one extra register Barb says. The underground installation didn't interfere with her trees or flowers, and the area that holds the piping has now grown over with grass.

Catherine Gaw and Elsie MacDonald say they weren't aware of alternative heating options when they built their home in Sackville, NB, five years ago. Their home had electric heat but they wanted that changed. "Our decision to go with geothermal heating was based partly on ecology-leaving less of an environmental footprint-and partly on theology. I believe we are caretakers of the earth," says Gaw, who is an ordained minister. They did some research and decided to have geothermal heating installed in February 2008. They were pleased that the Nordic heat pump used in the system is made by Maritime Geothermal Ltd. in Petitcodiac, NB, since supporting local business was an important consideration.

"Geothermal gives a more level, constant kind of heat," Gaw says. She and MacDonald use less than half the electricity they used before converting, and enjoy the dual heating cooling options.

Gaw and MacDonald, who qualified for both federal and provincial grants, believe more should be done to make grant programs accessible to more people. As it is now, the homeowner pays $150 for an energy audit (this can be refunded to modest-income earners), pays the cost of installing the geothermal system upfront-which can cost from $15,000 to $25,000-and then applies for grants. Gaw was able to get $2,000 from the New Brunswick government and $3,500 from the federal government. She says many homeowners couldn't afford to switch unless the program provided grants in the beginning, not after installation. Gaw says the New Brunswick government does offer a $10,000 interest-free loan, but that might not appeal to homeowners with mortgage payments and other financial commitments.

Both installations were done by Mark McCormick. Installation takes seven to 10 days, if not interrupted by bad weather. The installers remove the old wood, oil or propane furnace, replace it with the heat pump, install the pipes in the ground and connect the heat pump.

Horizontal loops require a quarter to half an acre of land. Vertical loops require about 1,000 square feet. Vertical loops are often necessary in city locations where lots are smaller. Bedrock is also a concern in some locations.

McCormick says that while the installation is costly, homeowners will see a payback in savings over 10 years. The benefits of geothermal heating are both economic and environmental: a savings of up to 66 per cent over electric heat; a two-thirds reduction in use of fossil fuels; clean energy, use of renewable energy and no combustion; heating and cooling from the same system and durability.

Resources

• Canadian GeoExchange Coalition: geo-exchange.ca
• advancedsolutions.ca
• conservens.ca 1-800-670-4636
• efficiencynb.ca
• gov.pe.ca/oee/
• Earth Energy Society of Canada:  earthenergy.org

Other Uses:

• radiant in-floor heating
• driveway systems for melting snow and ice
• hot tubs
• hot water