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Does a High AFUE Rating Guarantee I’ll Save Money with a New Furnace?

question-mark-badgePlanning for a new furnace installation in Plattsburgh, NY means balancing out multiple factors to find the right furnace model to meet your home’s heating needs. You probably already know about at least one important furnace stat: AFUE, which is the standardized measure for furnace energy efficiency. Does it make sense to purchase only a furnace with the highest AFUE rating you can find? Is that a guarantee you’ll save money on heating your home in the future?

There’s a Simple Answer—But It Needs a Longer Explanation

The simple answer is: “no.” AFUE is not a guarantee you’ll save money. AFUE is information about how the furnace performs, but it doesn’t automatically mean the furnace will reduce household energy bills during the winter. We’ll explain further how AFUE is measured and how it can affect your decision for furnace installation.

AFUE = Annual Fuel Utilization Efficiency

The AFUE rating is a percentage that indicates how efficient a furnace model is at converting the fuel supply into actual thermal energy. For example, a gas furnace with 90% AFUE will convert 100 units of natural gas into 90 units of heat, losing 10 units to exhaust. AFUE is measured over a year’s performance, rather than a single test. This means that a furnace will at times work at lower or higher efficiency levels than its AFUE.

The Range of AFUE Ratings for Furnaces

What type of AFUE ratings can you expect from modern furnaces?

  • Older furnaces with standing pilot lights have AFUE ratings as low as 56% and as high as 70%. If you live in an older house that still has its original furnace (and you’ll find plenty of these vintage homes in this area), it probably has an AFUE in this range… and it’s time for an upgrade.
  • Mid-efficiency furnaces that use electronic ignition and lighter heat exchangers have AFUE ratings between 80% and 85%. Chances are high this is the type of furnace you currently have.
  • New high-efficiency furnaces that use sealed combustion and variable speed fans can score up to 98.5% AFUE. In order for a gas furnace to earn the ENERGY STAR label from the Department of Energy, it must have a minimum of 90% AFUE.

Why High AFUE Won’t Necessarily Save Money

In order for a furnace to deliver on the promise of its efficiency rating, it must be correctly installed and sized for a house, and it must have a sealed ventilation system without leaks. A furnace that isn’t matched to a home may be efficient at converting fuel to energy, but it will still use more energy than it should. A ventilation system that allows heat to escape through leaks in the ducts will also waste an immense amount of energy, and that will undercut even the highest efficiency rating.

Professionals Will Help You Find the Right Furnace

We mentioned earlier that finding the balance of factors is key to a proper furnace installation. This is where you’ll need professionals; they’ll balance the energy efficiency of a new model with the specific heating needs of your house. They’ll also help to ensure the ventilation system is in the best shape possible. You can trust to our team to see that you end up with a furnace that will lower your bills while keeping your family warm.

Look to Red Rock Mechanical LLC—Serving Northwest Vermont and Plattsburgh, NY area for over 23 years.

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