Stay Comfy Blog

Consumer Guide: How to Understand the SEER Rating


Although we are heading into the colder months, that doesn’t mean it’s not a good time of year to be on the lookout for deals on air conditioners or start planning on upgrading your current model for next year’s cooling season. In order to really understand what you are looking for when buying a new AC, you first need to understand what a SEER rating is.

Understanding SEER

Basically, SEER, or Seasonal Energy Efficiency Ratio, is an efficiency rating for air conditioners and air conditioning systems as deemed by the Air Conditioning, Heating, and Refrigeration Institute (AHRI).

Keith Hill, technical support manager at Minnesota Air, explains it as the annual average of the amount of cooling BTUs generated by the system for each watt of electrical energy consumed. Put simply, a SEER rating is determined by looking at the amount of cooling produced – or heat energy moved from inside to the outdoors (BTUs) – divided by the amount of electricity used (watts). Products with higher SEER ratings are more efficient.

“SEER comparison can be used to accurately estimate savings when you are in the market for an upgrade,” says Keith. “Your new system SEER divided by the old system SEER is a very accurate estimate of how much you will save.”

For example, if your new model is 16 SEER and your older model is 10 SEER, you divide 16 by 10 to equal 1.60. Put in percentages, that means your new system will provide 60 percent more BTUs into the home than the old system for the same electrical energy used, he says. 

Proper SEER Achieved By Proper Installation

Keith reminds homeowners that a SEER value is only achieved if the whole system is replaced. That means you need the outdoor unit to be at the same SEER rating as the indoor unit in order to have it operate at peak efficiency.

“Some would have you believe that they can replace only the outdoor unit and you will realize the rated SEER value, but there is no rated SEER value on just the outdoor unit,” he says. “A new outdoor unit with an old indoor unit (A-coil or evaporator coil) is an unknown – there is no way of knowing what the system efficiency will be.   

He suggests getting the rating in writing to make sure you are getting what you are paying for – either the manufacturer’s specification sheet or a certificate from AHRI. Most utility efficiency rebates require a certificate from AHRI, but as a buyer, you should too.

 Another important item to understand about SEER ratings is that you really need to get it installed by a professional who knows what they are doing in order to achieve that rating. The technician should not only install it correctly with the rated airflow, but also the proper refrigerant charge, Keith says.

“System efficiency can be affected by as much as 25 percent if the refrigerant charge is off 10 percent. This is why you hire a pro that has the training and the credentials to prove it.”

Do You NEED A Product With A Higher SEER Rating?

Most basic AC models sold today have much higher SEER rating compared to the basic models from a few decades ago. In fact, according to the Department of Energy, “today's best air conditioners use 30% to 50% less energy to produce the same amount of cooling as air conditioners made in the mid-1970s. Even if your air conditioner is only 10 years old, you may save 20% to 40% of your cooling energy costs by replacing it with a newer, more efficient model.”



Find a Stay Comfy Minnesota Dealer Near You

Learn More