Furnace Energy Efficiency

Energy Efficiency Rating

All new furnaces available today are high-efficiency, with an Annual Fuel Utilization Efficiency (AFUE) rating of 90% to 98%.

  • AFUE measures the amount of fuel entering a furnace that is converted to heat vs. the amount of fuel lost. An AFUE of 90% means 90% of the fuel converts to heat, while the other 10% of the fuel is lost out of the chimney.
  • Select a high-efficiency furnace with and AFUE of 90 to 94% or an ENERGY STAR® furnace that meets or exceeds premium levels of energy efficiency.
  • Add a programmable thermostat for even greater energy savings.

Furnace labels


Energy Star

The most energy-efficient furnaces have an ENERGY STAR label and an AFUE rating of 95% or higher. Only furnaces with exceptional energy efficiency earn the ENERGY STAR label. See more information on the ENERGY STAR program.


Energy guide

The EnerGuide label compares the energy efficiency of a single furnace to similar furnaces sold in Canada. EnerGuide is regulated by Natural Resources Canada. Learn more about EnerGuide.

AFUE comparison chart

The higher the AFUE number, the more energy-efficient the furnace.

AFUE Comparison Chart
AFUE rating
Heating value
90 to 98%
90 to 98¢ of every heating dollar you spend translates directly into heat in your home.
78 to 82%
Loses 18 to 22¢ of every heating dollar.

*Mid-efficiency furnace sales were discontinued in Canada as of December 31, 2009.