Geothermal energy

Geoexchange technology uses the earth's renewable energy to heat or cool homes and buildings and to help provide hot water. A few feet beneath the surface, the earth's temperature remains fairly constant year-round – ranging from 7ºC or so in Canada's northern latitudes to about 20ºC in the deep south of the United States. Geoexchange takes advantage of this constant temperature to provide extremely efficient heating and cooling.

In winter, a water solution circulating through pipes buried in the ground absorbs heat from the earth and carries it into the home. The geoexchange system inside the home uses a heat pump to concentrate the earth's thermal energy and then transfers it to air circulated through standard ductwork to fill the interior space with warmth.

In summer, the process is reversed: heat is extracted from the air in the house and transferred through the heat pump to the ground loop piping. The water solution in the ground loop then carries the excess heat back to the earth. The only external energy needed for geoexchange is the small amount of electricity required to operate the ground loop pump and fan. It is more efficient and environmentally superior to "transfer" heat than to "create" it through combustion.

The basic technology has been around for more than 20 years, and many homeowners and businesses have been enjoying the benefits of geoexchange for much of that time. In recent years, though, many improvements have been made in the materials used, the installation methods, and the efficiencies of the compressors, pumps and other equipment.

Since a geoexchange system burns no fossil fuel to produce heat, it generates far fewer greenhouse gas emissions than a conventional furnace, and completely eliminates a potential source of poisonous carbon monoxide within the home. Even factoring in its share of the emissions from the power plant that produces electricity to operate the geoexchange system, total emissions are far lower than those of conventional systems.

While many homes have been fitted with geoexchange systems, commercial enterprises, including factories, retail stores, office buildings and schools are the biggest users of geoexchange to save energy and protect the environment. In fact, there are more than half a million installations in North America today.

If we make the same comparison across all commercial and residential segments in Canada, the potential for environmental benefit is staggering.

Geoexchange technology can be used in any part of the country since it transfers heat to and from the earth, which remains at a relatively constant temperature, rather than the air, where temperatures can vary greatly. While geoexchange costs more to install in homes than conventional systems, because of the ground loop piping, geoexchange systems typically have the lowest life-cycle cost of any heating and cooling system. Heating and cooling costs for a typical 2000-sq.-ft. home can run as low as $1 a day.

Moreover, installation costs have declined substantially in recent years, and they are expected to continue to fall, as more builders and contractors offer geoexchange systems, and as the industry develops innovative ways to install the systems faster and more efficiently.

Altogether, geoexchange systems are a very sound investment. The amount they save the homeowner every month in energy costs is more than enough to offset their higher installation cost. In addition, geoexchange technology remains a smart choice as it fosters sustainable development and the use of renewable energy.

Remembering that geoexchange also means extra savings on repair, maintenance and hot water bills, the energy efficiency of geoexchange adds value to your building whether home, apartment building, condo, skyscraper or sports stadium.