AFUE Ratings Guide
If you’re realizing that it’s time to upgrade your furnace, an early choice in the process is to decide on an efficiency rating. This will have an effect on your up-front costs and what you pay for home heating in the future. With this handy guide, you’ll understand more about AFUE ratings and how they affect you.
What Is an AFUE Rating?
AFUE is an acronym for Annual Fuel Utilization Efficiency. It is an industry-standard measurement for how efficiently a furnace or boiler converts fuel into heat for your home within a year. The higher the AFUE rating (on a scale of 0% to 100%), the more efficient the system is at converting fuel into usable heat.
How Is AFUE Measured?
AFUE ratings are estimated by calculating the ratio of the output of heat from the furnace or boiler to the amount of fuel it requires in the process. This calculation factors in the energy lost through exhaust gases, radiation and other variables that decrease efficiency. The result is expressed as a percentage, representing the amount of fuel converted into heat.
Figuring out a furnace or boiler’s AFUE rating involves conducting a standard test cycle to quantify the heat output and fuel consumption. This test cycle is structured to simulate ordinary heating conditions in the course of the year, including both on and off periods. The heating system is then run at peak capacity for an extensive period to define its peak performance.
What Is the Minimum AFUE Rating in 2023?
The U.S. Department of Energy (DOE) has gradually increased HVAC efficiency ratings over the past several decades in an effort to promote energy efficiency and reduce emissions that harm the ozone/atmosphere. In 2023, the minimum rating for new gas furnaces was set to 81 AFUE. From 2015 to 2022, the South and Southwest regions had a minimum rating of 80 AFUE, and the North mandated furnaces to be rated 90 AFUE or higher. Better AFUE ratings reduce energy consumption, lowers utility bills and decreases the environmental consequence of heating your home.
Why Do Gas Furnaces Jump from 80 to 90 AFUE?
When browsing around for new furnaces, you may notice many models around 80 and 90 AFUE, with little in between. This is due to the technology required to exceed 80 AFUE causes a considerable leap in performance.
The 80 AFUE threshold has been the minimum expectation for gas furnaces in the United States since the 1990s. At this level, furnaces convert 80% of the fuel they consume into heat, with the remaining 20% forfeited to the atmosphere through the flue.
Gas furnaces must use more advanced technology to secure higher AFUE ratings, such as two-stage or modulating gas valves, variable-speed blowers and supplementary heat exchangers. These techniques help the furnace grab heat from the fuel source more effectively, boosting efficiency from 80 to 90 AFUE or higher. Today’s top-rated furnaces cap out at about 98.5 AFUE.
How Do AFUE Ratings Affect Furnace Costs?
The price of a furnace with a higher AFUE rating is usually more than that of a lower AFUE-rated furnace. After all, more advanced technologies come at a cost. The exact cost difference will depend on the furnace make, size and efficiency rating.
When considering the up-front cost of a more efficient furnace, don’t forget the ongoing energy savings that awaits you. The potential to save money on fuel bills for the next ten years or longer will permit you to recoup the additional up-front investment.
Is It Smart to Buy a Furnace with the Highest AFUE Rating Possible?
Although a higher AFUE rating results in more efficient home heating and lower energy bills, this doesn’t necessarily mean every homeowner should choose a 95 AFUE furnace. Here are the factors to consider when evaluating costs and efficiency ratings:
- Local weather: The colder the weather, the longer your high-efficiency furnace runs, and the faster you will realize an overall savings from your investment. Because of this, higher AFUE ratings are most appropriate in cold climates that require more heating than cooling to keep a comfortable indoor temperature.
- How long you’ll live in this home: If you envision living in your home for many years, buying a high-efficiency furnace may be a wise investment since it will pay for itself over the coming years in energy savings. On the other hand, if you’re going to move within the next few years, the extra cost of a higher AFUE-rated furnace would not be recommended.
- Energy prices: The impact of an efficient furnace is more pronounced if your energy costs are high. You’ll realize the savings each month as your furnace converts a higher percentage of fuel into usable heat for your home.
Get a New Furnace Today
For help determining the perfect heating system for your needs and budget, rely on Service Experts Heating & Air Conditioning. We can help you weigh the up-front costs and long-term benefits of different AFUE ratings to inform your decision. We’re so confident you’ll be satisfied with our services that we offer a 100% satisfaction guarantee! To find out more or to schedule a no-cost furnace installation estimate, please call a Service Experts office near you.