SEER Rating And AFUE Rating. Why Do They Matter?

If you’re buying a new furnace or air conditioner, you’ll see SEER and AFUE ratings. So, what is a SEER rating and what is an AFUE rating?  

SEER (Seasonal Energy Efficiency Ratio) measures the cooling output of an air conditioner over a typical cooling season, divided by the energy it uses to do so, in Watt-Hours. 

AFUE (Annual Fuel Utilization Efficiency) measures how efficiently your furnace can utilize its fuel. The more efficient your furnace, the more heat you will get per unit of fuel. 

These ratings help you understand how efficiently the system you’re considering will use energy. The more efficient your system, the less energy it will use. This helps the planet and helps you reduce your utility bills, without changing your home’s temperature setting.  

Let’s take a closer look at the two ratings, so you understand how to find an efficient furnace or air conditioner.  

What does SEER mean? 

What does SEER really mean? The SEER ratio is calculated over an entire cooling season. Testers measure how much cooling an air conditioner produces, compared to how much fuel it uses within that time period.   

If you tested the same air conditioner yourself, you may not get exactly these results. There are many factors that influence the efficiency of your air conditioner such as the size of your home, duct work, and other variables. 

Still, the higher the SEER rating, the more efficient your AC. The minimum standard SEER for air conditioners is 13. However, most modern air conditioners have a rating ranging from 13-21. 

Units with a higher SEER rating usually have 2-stage or variable-speed compressors and a variable-speed blower. These units also lower your home’s humidity, which helps make the air feel more comfortable.  

What is an AFUE Rating? 

Unlike SEER, AFUE (Annual Fuel Utilization Efficiency) is a percentage of how much fuel a furnace can convert directly into heat.  Some furnaces convert only 30 percent of their fuel into heat, while others convert almost all the fuel.  

Every furnace or boiler needs to have a minimum AFUE of 78 percent. However, many models greatly exceed this efficiency with ratings over 90 percent. The remaining ten percent of the fuel is usually lost through the furnace’s exhaust. 

It’s also important to know that different fuels can be combusted at different efficiency rates. For example, electric heat is the most efficient type of fuel (with an AFUE of 100), but it’s also one of the most expensive ways to heat your home. 

Energy Efficiency Ratings  

It’s important to consider these rating when looking for an AC or a furnace. A higher SEER/AFUE rating will give you a more efficient means of heating/cooling your home, resulting in less energy wasted and more money saved. 

Lower SEER/AFUE appliances will still do their intended job but will run for longer and may chip away at your budget.  

 So, try to aim for a high energy efficiency rating, but ultimately choose the appliance that is the overall best fit for your home.  

Do you have more questions about the right SEER rating or AFUE rating for your heating and cooling systems? Contact Home Aire Care for answers to all your heating and cooling questions.