Skip navigation

Serving the South Puget Sound and Western Washington Areas Since 1976

Serving the South Puget Sound and Southwest Washington Areas Since 1976

24 Hour Emergency Service


Sunset Air Blog

How Does the AFUE Rating Affect My Furnace?

If you’ve ever installed or upgraded your furnace, you’ve probably heard the term “AFUE” used to describe its efficiency. Here in Tacoma, heating installation services will talk up high AFUE ratings, particularly when selling a more expensive model to you. That still doesn’t explain what an AFUE rating is or how it applies to heating. It’s reasonable to ask “how does the AFUE rating affect my furnace?” We can provide a few answers below.

AFUE stands for “Annual Fuel Utilization Efficiency,” which marks how efficiently the furnace uses energy. It’s listed as a percentage, representing the amount of energy the unit takes in divided by the amount it actually uses on heating. For example, a unit which uses 50,000 BTUs (British Thermal Units) of energy and creates 40,000 BTUs worth of heat has an AFUE of 40,000/50,000 or 80%. That means 80% of the energy is actually going to heat the home, with the other 20% being lost to waste and inefficiency.

In light of that, it’s obviously beneficial to use a furnace with the highest AFUE rating it can have. As time goes on, a furnace’s AFUE rating goes down, since parts wear out and the aging components need to work harder in order to do the same job. When the time comes to replace your furnace, it’s beneficial to look for one with higher AFUE rating, since it will save you money in the long run. Say your current furnace uses 100,000 BTUs and produces only 50,000 BTUs of heating power (an AFUE rating of 50%). Replacing it with a similar model with an AFUE of 90% — generating 90,000 BTUs of heating power for 100,000 BTUs used — means a savings of 40,000 BTUs, increasing your overall efficiency by 80% and saving you a great deal of money in the bargain.

Knowing how the AFUE rating affects your furnace will allow you to make an informed decision when purchasing a new one. The Tacoma heating installation experts like the ones at Sunset Air can provide further advice. We’re dedicated to your complete satisfaction and can find a new furnace for you with an improved AFUE rating that doesn’t break your bank. Give us a call today to set up an appointment!

Comments are closed.