Central heating and cooling systems are an integral part of homes and offices in Canada. Usually, little thought is put into the type of system that is installed in new buildings or retrofits. Most of the central heating systems currently installed, create heat by burning a fossil fuel while the growing proliferation of air conditioning has imposed a further burden on the generation and distribution of electricity. More advanced, non-combustion technologies operate not by burning a fuel, but by transferring or moving heat from one location to another.

Non-combustion or heat transfer systems include:
earth energy systems (ground-source / geothermal heat pumps)
solar thermal water heating
solar thermal air heating
advanced biomass combustion.

Each of these technologies are briefly described below.

Earth Energy Systems
Earth energy involves moving the solar energy that is stored naturally in our own backyards. The Earth absorbs 50% of the sun's energy and, no matter where you live, the underground temperature remains relatively constant throughout the year. Geothermal heat pumps harness this renewable energy source, and transfer it into the home for space heating and space cooling (air conditioning), as well as to heat domestic water for its occupants.

Canada has 30,000 geothermal installations in residential, commercial, institutional and industrial settings. The technology is widely used in northern Europe for heating, and is common in the southern United States for its ability to cool buildings.

A geothermal heat pump uses a refrigeration cycle to move heat between indoor and outdoor by way of a pipe buried in the ground. In winter, it moves the low level of heat that is constant below the frost line, into the house while, in summer, it uses the same pipe to remove heat from the house and transfer it to the ground, in the same concept as a refrigerator.

Some of the more unique applications of this technology include freezing the surface of an ice rink, and transferring the heat to a nearby building for the comfort of occupants.

For more information about geothermal heat pumps, check these links:
Earth Energy Society of Canada
Canadian Renewable Energy Network - Earth Energy Module
RETScreen module

Solar Thermal Water Heating
Every hour, the solar energy that reaches the Earth is greater than the amount of energy required by every human being ... the trick is to convert this solar heat into usable energy. While many people are aware that solar electric (or solar photovoltaic or solar PV) panels can convert sunlight directly into electricity, solar thermal (solar domestic hot water system) uses the sun's rays to heat water for domestic use. A solar thermal system can provide some or all of a home's annual hot water demand for showers, dishwashing, clothes washing, cooking, swimming pools and more.

Solar thermal systems provide numerous benefits over conventional water heaters which rely on natural gas or coal-fired electricity, including lower costs and reduced GHG emmissions. The amount of economic and environmental savings depends on several factors, such as the size of the collectors and storage tank, efficiency of your appliances, your region's sunlight, and the amount of water you want to heat.

The most common type of residential solar water heater for colder climates is a closed-loop active system, which circulate an antifreeze mixture through the pipes (collectors) to collect heat which then is transferred to the building water supply.
The most common commercial applications for solar thermal water heating is for clothes laundry, car washes and municipal swimming pools.

For more information about solar thermal water heating, check these links:
Canadian Renewable Energy Network - Solar Energy Module
Solar Water Heating Systems - a buyers Guide (NRCan publication)

Solar Thermal Air Heating
Heating air by using solar energy was a Canadian innovation, although the applications are more relevant to commercial facilities than to homes.

Thin metal tubes installed on the south face of a building will capture the sun's rays, and transfer the warmed air into the building's interior, usually as a pre-heating technique (ie: conventional energy will be used to boost the building's temperature to comfort level). A major requirement in many commercial facilities is for fresh air, so a solar thermal air pre-heating system allows the introduction of fresh air at a lower cost than conventional options.

In summer, the tubes will divert the warm air from entering the building, to lower the demand for space cooling and provide a form of air conditioning.

Manufacturers also claim that these metal tubes extend the lifespan of a building's wall, thereby providing non-energy benefits on top.
In addition, there is growing application of solar space cooling units.

For more information about solar thermal air heating, check these links:
Canadian Renewable Energy Network - Solar Energy Module
Solar Air Heating Systems - a buyers Guide (NRCan publication)

Biomass Combustion
Most Canadians know this technology by its simplest application: a wood stove.
There is combustion and there are carbon emissions, but the source of fuel is a renewable tree (or waste biomass) and the emissions are offset by the amount of carbon already sequestered by the tree during its life.

For more information about biomass combustion, check these links:
Canadian Renewable Energy Network - Biomass Energy Module
Biomass Heating Systems - a buyers Guide (NRCan publication)