Energy sources & equipment options

Energy sources & equipment options

Natural Gas

Furnaces in forced air heating systems, boilers in hot water systems, fireplaces and space heaters can be fuelled by natural gas. It is delivered to your house through an underground pipeline. (It is not available in some areas.)


Most equipment fuelled by propane is similar to that fuelled by natural gas. In many cases, the only differences are one or two small components that can often be changed by a registered contractor to convert a unit from one fuel to the other. Propane is delivered by truck and stored in a tank on your property.

Gas Equipment

Because of their similarities, natural gas and propane heating equipment are discussed together.

The term "gas" refers to both natural gas and propane. The cost of the two fuels differs, so remember to check the charts ( for cost comparisons.

There are three main types of gas furnaces:

  • conventional (with a seasonal efficiency range of 55 to 68 per cent);
  • mid-efficiency (78 to 82 per cent); and
  • high-efficiency (90 to 98 per cent).

Gas boilers have similar ranges of seasonal efficiency.

For an explanation of efficiency ratings for furnaces, boilers, heat pumps, air conditioners and hot water heaters, see

Older conventional gas furnaces and boilers

Some older furnaces and boilers, which are no longer produced but are still in use, require a continuous liner in a masonry chimney or a metal "B" vent chimney. The liner is needed because the combustion gases contain water vapour which condenses on masonry and causes deterioration over time. About 35 per cent of the heat from the fuel goes up the chimney with these models.

Mid-efficiency gas furnaces and boilers

These models remove more heat from combustion gases so that less heat escapes when the gases are exhausted and efficiency is improved. Depending on the circumstances, they might be vented through a wall or through a chimney.

High-efficiency (condensing) gas furnaces and boilers

These models extract so much heat from combustion gases in order to achieve their efficiency, that they can be safely vented through a narrow plastic pipe that runs through the wall.

A Word About …Conversions

As indicated, natural gas and propane equipment is often identical except for a few components. However, conversion of such equipment may only be performed by fitters licensed to work on the equipment involved, and such conversions are normally only permitted on equipment for which the manufacturer supplies a certified conversion kit. It is possible to convert equipment without a certified conversion kit. However, such conversions must be individually inspected by the Technical Safety and Standards Authority which, for residential applications, is a relatively costly procedure.

If conversion capability is important to you, confirm the possibility of legal conversion of the equipment before you buy.


A Word About … Efficiency

Under Energy Efficiency Act regulations, gas furnaces manufactured after January 1, 1992 and oil furnaces manufactured after September 1, 1994 must have an annual fuel utilization efficiency rating (AFUE) of at least 78 per cent to be legally sold in Ontario. Older, lower-efficiency (conventional) furnaces can be and are still used - for example, they may be the heating system in an older home that has not been updated - but such models are no longer produced.

Gas-fuelled Fireplaces

Gas fireplaces are sometimes used to provide space heating, though they are also sometimes chosen for aesthetic reasons. There can be significant differences in energy efficiency from one model to another, and the effective efficiency of some types can be significantly affected by how they are used. The considerations in selecting a gas fireplace are numerous and beyond the scope of this book, but if you are considering one, "All About Gas Fireplaces", available from Natural Resources Canada (contact information -, can guide you in your choice. It has information not only on efficiency ratings, but several other factors you should consider, both before selecting one, and in installing and using one.


Oil furnaces and boilers have a burner, a heat exchanger and a blower or pump. New oil furnaces made in Ontario are efficient. Oil is delivered by truck and stored in a tank, which is usually located in the basement.

Older conventional oil furnaces and boilers

Older, conventional oil furnaces and boilers with a standard burner have a seasonal efficiency generally ranging from 60 to 70 per cent. Like older, conventional gas furnaces and boilers, they are no longer produced. However, in an existing model that is working well, the seasonal efficiency can be improved by replacing the burner with a flame retention unit - usually a more cost-effective step than replacing the entire furnace.

New oil furnaces and boilers

A typical new oil furnace or boiler has a seasonal efficiency rating generally ranging from 78 to 86 per cent. Many of these units can be vented through the wall.

Oil stoves

There are free-standing oil space heaters with a visible flame now available. There are no efficiency standards for these products.

A Word About... Upgrading

An older oil furnace or boiler can often be upgraded to more than 80 per cent efficiency. The first step in making a decision about a possible upgrade or replacement of your oil furnace or boiler is to have a qualified service technician measure its steady-state efficiency. The technician can explain what could be done to increase efficiency and maintain safe operation. The technician can also estimate the remaining life expectancy of the existing equipment, the costs of an upgrade and the cost of replacement with all-new equipment.


Electric resistance systems can consist of a central furnace or boiler connected to an air or hot water distribution system, radiant panels embedded in the floor or ceiling or a baseboard space heating system. Electricity also powers heat pumps. When electric resistance heating is used in a new home, including as a back-up for an air source heat pump, the build-ing code requires the house to be built with higher minimum levels of insulation.

Heat Pumps

A heat pump is usually an electrically-powered system that can either heat or cool by transferring heat from one place to another. During the heating season, a heat pump extracts heat from either the air, ground or water outside the house, and transfers it indoors. In the summer the direction of the heat flow is reversed, extracting heat from indoors and transferring it outdoors, to provide air conditioning. Because they satisfy a substantial part of your heating needs by utilizing already available heat, rather than consuming electricity to generate all of the heat you need, heat pumps are significantly more efficient than electric resistance heating.

Heat pumps are sized in tons - one ton equals 12,000 British Thermal Units per hour (BTU/h) - and most home models range from 1.5 tons to 5 tons. There are three main types of heat pumps: air source heat pumps, earth energy systems and bivalent heat pumps.

Air source heat pumps

These most commonly-used heat pumps can provide all the cooling requirements of a home and most of the heating needs, but they require an auxiliary heating source during very cold weather. This can be either an electric resistance or a fossil fuel unit.

Earth energy systems

Also known as ground source heat pumps, these systems transfer heat from the ground, ground water or surface water and use it to provide home heating. For summer cooling, the process is reversed. If desired, earth energy systems can be equipped to provide domestic hot water year round. Electric resistance heaters may be installed to provide supplementary heating for the coldest days. They normally utilize much less electric resistance heat and offer significantly higher efficiency than air source heat pumps.


Many Ontario households use wood as their main fuel and even more use it as a supplementary source of heat. Most of these households are outside large urban areas where firewood is usually less expensive than other fuels. Before considering converting to wood heat for economic reasons, however, you should also take into account the need for storage space and the time and effort required to handle the wood and tend the fire. (For information on sources of firewood, see

The most common approach to wood heating today is a wood stove or high-efficiency fireplace installed in the main living area of the house. If the house is medium-sized and relatively new, this kind of equipment can provide almost all the heat needed. (See Space Heaters,

If you have an existing masonry fireplace, a high-efficiency fireplace insert could be a good option. And many models offer the pleasure of a visible wood fire. Older or larger houses may need the additional heating power offered by a wood-burning furnace. If your present heating system is a forced air furnace that uses a more costly fuel, you might want to consider an add-on wood furnace. It is installed beside the existing furnace and the duct work is modified so that it can be shared by both furnaces. Combination wood/oil or wood/electric furnaces are options for new or replacement systems.

Stoves that burn pellets made from wood or agricultural crops such as corn kernels are also available. Pellets are automatically fed into the burner and the householder simply dials in the required temperature on the thermostat.

When shopping for wood-burning equipment, visit several wood heat retail stores and discuss appliance selection, location and installation with a knowledgeable salesperson. Certification under the Wood Energy Technical Training program (WETT) indicates that the salesperson and installer have been trained in the proper, safe installation and operation of wood-burning equipment. Always buy wood-burning equipment that is certified for safety. Look for equipment labels bearing the names Warnock Hersey, Underwriters Laboratories of Canada (ULC) or Canadian Standards Association (CSA). It is also preferable to buy equipment that has been certified as meeting the U.S. Environmental Protection Agency (EPA) or Canadian CSA-B415 emission standards. These certified wood-burning appliances produce one-tenth of the chimney emissions and one-third higher efficiency than earlier units.

Outdoor Furnace

"Outdoor" wood furnaces or boilers are also on the market. They may appear attractive, because they will burn low cost material you would not think of putting in an indoor appliance and can burn for long periods between refueling. They can be low on efficiency and high on emissions. If you still want to consider one, it's advisable to check with your local municipal building officials and your local Ontario Ministry of the Environment office (see Blue Pages of your phone book or regarding acceptability for the location you have in mind.

Solar Energy

Like wood, solar energy is a renewable resource. Solar heating does not involve the combustion of fossil fuels, so it does not produce environmentally-harmful emissions. It can be as simple as south-facing windows serving as passive solar collectors. Passive solar heating is free and should be an important consideration in the design of homes. Homes built to high levels of energy efficiency and designed to make the most use of free solar heating can save hundreds of dollars a year on energy bills.

Other Energy Sources

Residential systems are available to generate electricity from sunlight or wind. In certain situations, such as remote locations, one of these may be the most practical option. In addition, the government government is establishing standardized processes and technical requirements which will require electricity distributors to allow customers with qualifying generation equipment to supplement their utility electricity needs with power they generate themselves. Check the listings in for information on alternative energy choices.


© 2005 Queen's Printer for Ontario

This information is provided as a public service, but we cannot guarantee that the information is current or accurate.
Readers should verify the information before acting on it.