What Is an AFUE Rating As It Relates to a Furnace?

What Is an AFUE Rating As It Relates to a Furnace?

The annual fuel utilization efficiency measures the efficiency of a furnace by comparing the annual heat output of a furnace to the total annual fossil fuel energy consumed by that furnace. The Federal Trade Commission requires that new furnaces display the AFUE to allow consumers to compare efficiency when shopping.

The AFUE of an all-electric furnace is between 95-100%, meaning that 5% or less of the electricity consumed by the furnace escapes from the furnace without being turned into heat. As of 2015, the minimum allowable AFUE for non-weatherized gas furnaces and non-weatherized oil-fired furnaces, excluding mobile home furnaces, are 80% and 83%, respectively.