AFUE Ratings Guide
If you’re thinking about upgrading your furnace, an important first step is to determine an efficiency rating. That rating selection will influence 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 a standard for measuring how efficiently a furnace or boiler changes fuel into heat for your home within a 12-month period. 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 a furnace’s heat output to the amount of gas or diesel it consumes in the process. This calculation accounts for the energy lost through exhaust gases, radiation and other elements that decrease efficiency. The result is displayed as a percentage, representing the amount of fuel converted into heat.
Figuring out a furnace’s AFUE rating entails conducting a common test cycle to assess the heat output and fuel consumption. This test cycle is intended to simulate ordinary heating conditions throughout the year, including both hot and cold periods. The heating system then functions at full capacity for an extended period to establish 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 few decades with hopes to promote energy efficiency and reduce greenhouse gas emissions. 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 called for furnaces to be rated 90 AFUE or greater. Better AFUE ratings cut down energy consumption, lowers power bills and curbs the environmental impact of heating your home.
Why Do Gas Furnaces Jump from 80 to 90 AFUE?
When browsing around for new furnaces, you may discover many models around 80 and 90 AFUE, with little in between. This is because the technology necessary to exceed 80 AFUE forces a considerable jump in performance.
The 80 AFUE threshold has been the minimum expectation for gas furnaces in the USA since the 1990s. At this level, furnaces convert 80% of the fuel they consume into heat, with the remaining 20% sacrificed to the atmosphere through the flue.
Gas furnaces must integrate more sophisticated technology to secure higher AFUE ratings, such as two-stage or modulating gas valves, variable-speed blowers and supplementary heat exchangers. These features help the furnace extract heat from the fuel source more effectively, raising efficiency from 80 to 90 AFUE or higher. Today’s top-rated furnaces cap out at approximately 98.5 AFUE.
How Do AFUE Ratings Influence Furnace Prices?
The total price of a furnace with a higher AFUE rating is typically more than that of a lower AFUE-rated furnace. After all, more advanced technologies come with a higher price tag. The exact cost difference will depend on the furnace make, size and efficiency rating.
When thinking about the initial cost of a more efficient furnace, don’t forget the ongoing energy savings that awaits you. The real chance to save money on energy bills for the next decade or longer will allow you to recoup the additional up-front investment.
Should You Buy a Furnace with the Highest AFUE Rating Possible?
Although a higher AFUE rating results in more efficient home heating and more affordable energy bills, this doesn’t necessarily mean everyone should buy a 95 AFUE furnace. Below are a few factors to consider when contrasting costs and efficiency ratings:
- Seasonal weather conditions: The colder the weather, the more frequently your high-efficiency furnace runs, and thus, provides an earlier ROI. For that reason, higher AFUE ratings are most suitable in cold climates that take more heating than cooling to sustain a comfy indoor temperature.
- How long you’ll live in this home: If you imagine living in your home for quite a while, purchasing a high-efficiency furnace may be a smart investment because it will pay for itself over time in energy savings. But, if you’re going to move within the next few years, the extra cost of a higher AFUE-rated furnace would not be recommended.
- Fuel costs: The benefit of an efficient furnace is more evident when energy costs are higher. You’ll realize the savings each month when your furnace converts a higher percentage of fuel into usable heat for your home.
Install a New Furnace Today
For help determining the best furnace system for your needs and budget, choose Service Experts Heating, Air Conditioning & Plumbing. We can help you figure out the up-front costs and long-term benefits of different AFUE ratings to guide your decision. We know you’ll love working with Service Experts so much so that we offer a 100% satisfaction guarantee! For more information or to schedule a complimentary furnace installation estimate, please contact a Service Experts office near you.