Your Furnace: Efficiency & Energy Bills

Understanding AFUE & its Effect on your Heating Costs

Looking for a High Efficiency Furnace?

The heating and air industry is constantly evolving and improving. That means now, more than ever, you have a better opportunity to heat your home more efficiently and pay lower energy bills with a new heater installation.

Determining which furnace best fits your budget and energy efficiency expectations can be complicated. Many different factors determine how a heating system will operate, how much energy it will use, and how much it will cost you. When we are discussing cost, we are talking about two different things: both the upfront price for installing a new heating system as well as how much you spend each month on your energy bills. Fortunately, if you decide to purchase a new furnace and handle that initial cost now, you may find that the money you save over the next 5-10 years in monthly energy bills could greatly make up for that purchase price.

What is the meaning of AFUE?

When it comes to finding a high efficiency furnace, one of the main heating terms to understand is AFUE, which is the Annual Fuel Utilization Efficiency rating. The AFUE was created by the Environmental Protection Agency (EPA) for evaluating the energy efficiency of furnace systems. The EPA sets minimum standards for AFUE, just as it does for the SEER rating of air conditioners. For many years the minimum AFUE rating was 78. But within the past decade, the EPA raised the minimum AFUE rating to 80 and 83 depending on the specific type of furnace being installed.

AFUE vs SEER

You may have heard about the SEER rating when it comes to air conditioning. The AFUE is essentially the furnace version of the SEER rating. How are they alike? Both ratings determine how much energy is used to produce the desired temperature air (cooling for SEER, heating for AFUE). But how these numbers are displayed are very different. While the SEER rating uses an arbitrary number system (typically AC units have a SEER rating between 13 and 26), the AFUE rating is based on a percentage number.

AFUE: What the Numbers Mean

An AFUE Rating of 80 means that only 80 percent of the energy consumed by your furnace turns into heat. That other 20% of energy was used by your furnace but did not result in producing heat for your home. To put it in terms of money, for every dollar you spend on your gas bill to operate a gas furnace, you will only get about 80 cents worth of heat.

What AFUE ratings do most furnaces have? Older, low-efficiency heating systems typically have an AFUE rating of 56 to 70. Mid-efficiency furnaces have AFUE ratings between 80 and 83. Any furance with an efficiency of 90% (AFUE 90) or higher is considered high efficiency.

Cost Savings Depend on Type of Energy Source

You may think being more energy efficient also means saving money. You’d mostly be right. But when it comes to saving money on energy bills, utilizing only the AFUE Rating to select a furnace would be a big mistake. You see, while you may find which furnace is the most efficient with the energy it uses, knowing what kind of energy it is using is incredibly vital. The perfect example of why this is important is the electric furnace. Electric furnaces are the only kind of heaters that have the capability of having a “perfect” AFUE Rating of 100 (100% energy efficient). However, the energy source that furnace is using is electricity.

Electricity is one of the most expensive energy types you could pay for. So although your electric furnace is using 100% of energy consumed to produce heat for your home, the cost of that energy consumption is more than consuming a higher level of a different type of energy source.

The monthly cost to operate an AFUE 100 electric furnace would likely be much higher than having an AFUE 90 furnace that runs on natural gas. For the same amount of energy, the cost of electricity is about twice that of natural gas. For a price comparison, you can expect that the monthly energy bills of operating an electric AFUE 100 furnace would be equivalent to a gas AFUE furnace of only 50% efficiency.

Unlike electric furnaces that have the ability to reach 100 AFUE, gas furnaces, even the most efficient model, can only get as high a rating as AFUE 98.

How Much Money will a High Efficiency Furnace Save You?

If your home is currently being heated by an oil or gas furnace ten years old or older, you may be dealing with a furnace with an AFUE rating of 60 (or even lower). If you upgraded from an old, low-efficiency furnace to a heating system with a unit that had an AFUE of 97% efficiency, you can expect to see a savings anywhere from $300-700 every year on your monthly energy bills.

IMPORTANT NOTE: When a Furnace isn’t as Energy Efficient as its AFUE Rating

With a 90 AFUE furnace you should expect to have 90% of the energy used turned into heat. But unfortunately for many homeowners, they may be getting only 80% or even less of that energy-to-heat conversion.

The AFUE rating doesn’t factor in any problems like heat loss due to other issues with your home or heating system. That’s why expert installation is vital. If the entire heating system wasn’t properly installed including the necessary work required for the ductwork, you could be losing as much as 35% of that heat. This is why it’s essential you hire only trained and qualified heating installation professionals. To achieve the most cost-effective system, precise installation is essential to get the full efficiency your furnace is rated to provide.

Other Factors to Consider when Buying a Furnace

In addition to being aware of the AFUE rating, you will also want to make sure to get the right size of furnace. But be aware, bigger isn’t always better. Where do you live? How large is your house? Is your insulation good? Depending on several factors like these, there is a right way to determine the proper size of furnace your home needs. A furnace’s BTU rating is also important to understand. Other factors you will need to consider are which type of air flow you want your furnace to have and where it will be placed inside your home.

Making sure you have the right level of heat distributed evenly throughout your house is not a one-size-fits-all undertaking. That’s why Hanna Heating and Air take a thorough evaluation of your home and heating system to determine the options that are best for you. We work to understand the issues that are most important to you, whether it’s energy efficiency, price or humidity level control. We even have new NASA-researched technology that cleans your air, ideal for people who suffer from allergies or live with pets. Contact us at Hanna Heating and Air for a free home evaluation to determine your best options for a high efficiency furnace that is right for your family and your budget.