What Does An AFUE Rating Mean?


When you’re in the market for a new heating system, it’s best to know everything you can to help you make a more informed decision. There is a long list of information on heating units you can familiarize yourself with, but one that should definitely be toward the top is the meaning of AFUE.

The AFUE rating on your unit can end up saving you energy, increase the heating capabilities in your home, and even save you money. Professionals like Service Legends can provide you with the most accurate rating based on heat output and fuel input, but there are ways for you to get a general rating on your own as well.

Here are a few beneficial details about AFUE ratings and their meaning:

What Is an AFUE Rating?

AFUE is an acronym that stands for annual fuel utilization efficiency. It’s expressed as a percentage with the ratio representing how efficiently a boiler or furnace converts energy into heat, where 90 means that 90 percent of the energy used is generating heat while the remaining 10 percent is lost.

The higher the percentage is, the more effectively your furnace or heating system will perform. All furnace manufacturers are required by the Department of Energy to display the AFUE of each of their units. This helps to give consumers a better idea of how well it will perform in their homes.

Why Does a Good AFUE Rating Matter?

When it comes to heating a home or building, owners want to be sure they are getting optimal efficiency which can be better assured with a better AFUE rating. Generally, the higher the AFUE rating, the more efficient the unit will be, so scores closer to 100 are better. A good AFUE rating will heat your home faster while also saving you money on energy costs.

The further the AFUE rating is from 100, the higher the margin is for energy to be wasted and heat to escape the home. That heat can leak through small gaps or general inefficiencies within the unit. For instance, if you decide to purchase a heating unit with an AFUE rating of 80, that means the remaining 20 percent of energy being used by the unit won’t result in heating your home. Though that unit may be cheaper, it could end up costing you more in the long run.

Related: What Standards Does A New Furnace Need to Meet?

How Can That Be Used When Purchasing a Furnace?

When you’re in the market for a new heating system, it can be helpful to be familiar with the meaning of AFUE. Using an AFUE rating is a great way to determine how efficient one heating system can be compared to another. For this reason, it’s helpful to know where to find the AFUE rating on a unit that you’re considering purchasing.

The AFUE rating is listed on the unit because it helps consumers make a more informed decision on which heating unit to buy. You can do this by looking at the Energy Guide label on the unit. This label is typically bright yellow and easy to spot. While this is the best way to find the most up-to-date and accurate AFUE rating, you can also find an AFUE rating in the owner’s manual or on the manufacturer’s website.

Because the AFUE rating can change over time, it’s best to go off the number given on the Energy Guide label or have an HVAC professional figure out the rating for you.

What Else Should You Consider When Buying a Heating Unit?

While AFUE ratings are an important thing to consider when buying a heating unit, there are other things that can help shape your decision. Here are a few things you should also keep in mind:

  • Overall Cost: Price point is definitely something to consider when shopping around for a heating system. Finding the best deal is the objective for many, but the initial price of the unit isn’t the only cost you should be considering. While a cheaper unit may save you money at first, a low AFUE rating and overall efficiency could end up costing you. If money is a concern for you, both the initial cost and the overall costs of the unit’s life span should be considered. A unit with a higher AFUE rating could mean you pay more upfront but save on your monthly payments for years to come.
  • Fuel Type: The type of fuel you’ll be using is another thing to consider when you’re buying a new heating unit. Prices usually vary quite a bit between natural gas, propane, and heating oil. Understanding what fuel options are available with the heating unit you purchase and which will be the most cost-effective are good things to consider before deciding on a heating unit.
  • Personal Heating Needs: Your personal heating needs will also play a large role in the kind of heating unit you end up purchasing. If you live in an area that only requires heat for a few months out of the year, then you may not need to invest in the latest or most efficient heating unit out there. On the other hand, if you use heat for half the year or more, you may save tremendously by ensuring you have a heating unit with a high AFUE rating.

How Can You Get the Most Out of Your Heating Unit?

Keeping your unit in great condition for years is a smart goal to have. In addition to buying a unit with a high AFUE rating, there are other things you can do to increase the efficiency of your heating system. One of those ways is by keeping up with scheduled maintenance with the help of professionals.

Regular maintenance of your unit will help it to continue its high efficiency by avoiding the loss of any potential heat. Service Legends can check your unit and spot any small issues before they become bigger and more costly problems. Replacing parts when necessary, checking for leaks in the unit itself or the vent system, as well as fixing the unit at the first sight of an issue can help to maintain the optimal efficiency of your unit and possibly extend its life span.

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