Snell Heating & Air Conditioning

Trusted for Generations

Annual Fuel Utilization Efficiency (AFUE)


Most homes in the United States are heated with furnaces or boilers and if yours aren’t energy efficient, they could be costing you a fortune. In preparation for National Cut Your Energy Costs Day this Saturday, we wanted to highlight the importance of upgrading to a high-efficiency furnace or boiler:

Our expert technicians are here for youSchedule Online Today

How can you tell if your furnace or boiler is energy efficient?

Well, we should start by letting you know how efficiency is measured. The Federal Trade Commission requires new furnaces and boilers to display their annual fuel utilization efficiency (AFUE) so consumers can compare models. AFUE is a measure of how efficient the appliance is in converting energy to fuel to heat your home. The higher the AFUE rating, the more energy efficient the appliance is.

Here is a breakdown of low, medium and high-efficiency heating systems:


56% to 70% AFUE
Continuous pilot lightiStock_000005541542_Large
Natural draft creates a flow of combustion gases


80% to 83% AFUE
Electronic ignition (no pilot light)
Exhaust fan controls flow of combustion air and gases more precisely


90% to 98.5% AFUE
Sealed combustion
Condensing flue gases in a second heat exchanger for extra efficiency

When shopping for a new furnace or boiler make sure to look for the ENERGY STAR label and the AFUE rating. Replacing your old system and upgrading to an energy efficient one will convert nearly all of the fuel to heat for your home. As a result, you’ll start seeing lower energy bills that won’t deplete your wallet.

Need somebody to properly install your new boiler or furnace? Give Snell Heating & Air Conditioning a call today at (703) 450-6300.