What Are AFUE and SEER?

Published on: June 1, 2020

Understand What AFUE and SEER mean.

AFUE and SEER are ratings that measure the energy efficiency of your heating and cooling systems.  The US Department of Energy (DOE) requires all furnaces and air conditioners to have a rating. The DOE also sets minimum energy efficiency standards on these appliances.  Understanding AFUE and SEER can help you determine the most efficient heating and cooling system for your home.  

What is AFUE?

AFUE stands for Annual Fuel Utilization Efficiency, and it measures how efficient your furnace is at converting fuel to energy.  Think of it as the miles per gallon (MPG) rating for your vehicle. 

Obviously, the higher the rating, the better the efficiency. But what is a good rating?  Older, lower efficiency furnaces usually have a rating of between 56% to 70%.  The DOE now requires all new furnaces to have a minimum AFUE rating of 80%.  Most mid-efficiency heaters usually have a rating between 80% to 83%.  High-efficiency models have an AFUE rating of 90% to 98.5%.

Your geographical location will partly determine what AFUE rating is necessary for your home. Southern climates would operate sufficiently with a mid-efficiency furnace. Northern climates should invest in a high-efficiency system. Bryant offers a line of furnaces with AFUE ratings up to 98.3%.  Carrier provides a range of furnaces with AFUE ratings up to 98.5%

What is SEER?

SEER stands for Seasonal Energy Efficiency Ratio and is the standard measurement for how efficiently your air conditioner runs. A SEER rating is calculated by dividing the total amount of heat removed from your home during a typical cooling season (BTU, British Thermal Unit) by the total electrical energy used during that same season (WH, watts per hour).

Like AFUE, the higher the SEER rating, the better the efficiency.  Effective 2023, the DOE will enforce a minimum SEER rating of 15 for residential homes in the South and 14 for the North. Older systems are rated 8 or 9. However, newer air conditioning systems have a SEER rating of between 13 to 21.  Bryant offers a line of cooling units with SEER ratings up to 20.5.  Carrier provides a range of cooling systems with SEER ratings up to 26. 

Need Further Explanation?

Many factors will impact what AFUE and SEER rating appliances would be best for your home.  You will also need to make sure that your heating and cooling systems are matched.  A qualified HVAC professional can provide you with clear and concise information about the models that will be best for your home and comfort requirements.  Let AC Southeast® help you find a trusted HVAC professional in your area today.