Tool · Efficiency savings
What will a higher AFUE save me?
AFUE is the share of gas turned into heat. Going from 80% to 96% saves about 17% of heating gas; going from 96% to 98% saves about 2%. This tool converts your gas use into that saving, using a price you enter — the result is an estimate, never a guarantee.
How the estimate works
The gas saving from an AFUE change is approximately annual-heating-gas × (1 − oldAFUE ÷ newAFUE). The formula assumes the same heat output is needed and that the certified AFUE figures are right for your installation position — both are approximations. Actual savings depend on the house, the installation and your behaviour.
Method: GasFurnace.ca estimate from the AFUE definition under the Natural Resources Canada gas-furnace regulations (referenced on the AFUE guide; page checked 2026-09-07). Dollar figures require your own gas price; no utility rate is assumed here. Savings shown are estimates, never guarantees.