Heating system efficiency is calculated two ways. The first is combustion efficiency, which tells you how effectively fuel is converted into useful energy while the system is running. The second, more accurate measure of effectiveness is annual fuel utilization efficiency (AFUE), which accounts for start-up, cool-down, off-cycle loss and other factors that affect real operating performance.

78% - the legal minimum for new furnaces on the market today.
80% - another once-impossible degree of efficiency that means drastically lower gas bills than you probably have with an old furnace, only being manufactured until December 31, 2009
98-plus % - currently the highest efficiency you'll find

If you have an older furnace and the AFUE is lower than that of the new furnaces on the market, it could save you significant dollars to replace the furnace.

Buy High Efficiency and Save Money

If your existing system’s AFUE is 60% and the AFUE for a new high-efficiency system is 92%, the savings would be nearly 35% off your existing heating costs. If your annual heating bill is $800.00, you'll save $278. When you consider most furnace systems last about 15-20 years, that adds up to a lot of money.

New Minimum Standards for Residential Gas Furnaces

A new national minimum energy performance standard will go into effect December 31, 2009. All residential gas furnaces sold in Canada will require a minimum fuel efficiency of 90%. This is part of Canada's efforts to address climate change. The first time installation of high efficiency products requires changes to the venting system for both the furnace and, in some cases, the water heater. In some situations, through-wall venting can be more complex and expensive to resolve.

Rebates are available to those who qualify

Gas Furnaces Are Available in Different Configurations

A Single Stage gas furnace has only one speed - full blast. As the thermostat calls for heat it will quickly warm your home to the setting on the thermostat by delivering all the heat in one blast. When the desired temperature is reached, it will shut off.

When your thermostat calls for heat, your furnace will run on the first stage (low burner, low air flow), and only go to the second stage if the indoor air temperature drops during the first stage. Two heating stages eliminate the frequent starting and stopping common in single stage units. The furnace will run longer, but provide more consistent air filtration, air circulation and temperature distribution.

Variable Speed Motor

Variable speed fans spin at different speeds depending on your home's heating and cooling needs. They operate at lower speeds for more steady air flow in your home, which can help control humidity, noise and electrical costs. When needed, the fan speed will automatically increase to meet the higher demands of your system.

Modulating Furnace

Automatically makes slight operating adjustments to achieve maximum efficiency. The furnace's gas valve operates between 40% and 100% (depending on the furnace make) of total capacity, in small increments, continuously regulating the amount of fuel burned according to the thermostat setting. This works in conjunction with a variable speed motor

Trane Furnaces