What does AFUE mean on a gas furnace?

95% AFUE is a measure of the gas furnace’s energy efficiency.

It means that, on average, 95% of the gas the furnace uses will be converted to heat while the remaining 5% is lost up the flue (an exhaust pipe).

Put another way, for every $1 you spend for heating, 95 cents of it heats your home and you lose 5 cents up the flue.

AFUE lets you compare the efficiency of different furnaces the same way miles per gallon (MPG) allows you to compare the energy efficiency of different cars.

Do I need a 95% AFUE furnace?

Need? No.

The current federal minimum AFUE for gas furnaces is 80%. Now, if you do more research online about the minimum AFUE, you may see that the minimum AFUE for northern states was going to be bumped up to 90% in May 2013.

However, the legislation pushing for that 90% standard never got passed. So the minimum AFUE you can get IS 80% even if many other sources tell you otherwise.

Anyway, while you don’t need a high-efficiency 95% AFUE furnace, it can save you money. How much? Glad you asked…

How much can a 95% AFUE furnace save me?

It depends on the furnace you have now.

For a quick estimate, check out the table below from Energy.gov. Find the row with the AFUE of your current furnace on the left and follow it over to the 95% AFUE column.

U.S. Department of Energy, Annual Estimated Savings for Every $100 of Fuel Costs by Increasing Your Heating Equipment Efficiency. Assumes the same heat output.

The numbers shown are how much you’ll save for every $100 you currently spend in heating costs. For example, if you currently have a 50% AFUE furnace and spend $300 a year on heating your home, a 90% AFUE furnace will save you about $142.08/year ($47.36 x 8).

More important: find a good furnace installer

The most important part of getting a new furnace is finding a quality furnace installer. A standard efficiency furnace that’s well installed will be more energy efficient than a high-efficiency furnace that’s poorly installed.

Get pricing on a furnace for your Kansas City area home

If you’re in Olathe, Overland Park, Lenexa, Shawnee, or the Kansas City area, set up a free in-home estimate with us, and we’ll help you find the right furnace for your home.