Smile Heating & Cooling Inc. More About Furnace Inspection & Repair | Page 5

HAVING YOUR FURNACE
INSPECTED
• A furnace measures its efficiency level by the (AFUE) “annual fuel utilization efficiency”.
This is required by the Federal Trade Commission to be displayed on the furnace so that
consumers may compare the efficiency of one furnace to another. The AFUE is the amount
of energy the furnace transfers from energy to heat during the course of a year's’ time.
• If your furnace has a 90% AFUE rating, 90% of the furnace’s energy is being converted to
heat, and the remaining 10% is escaping through the chimney or other areas within the
home. However, some heat is lost through a faulty duct system which can amount to as
much as 35% when there are furnace ducts located in the attic, garage or other areas of the
home that are not completely conditioned as living quarters.