What is the best SEER rating?

A SEER rating is something you’ve likely encountered without truly knowing what it means. It’s also a term that can strike fear into the heart of consumers as they try to decide between a 14 or 21 SEER unit. Our goal is to help you navigate those murky marketing terms so you can quickly find out the best SEER rating to suit your needs while keeping your home cool and efficient.

SEER Ratings Explained

seer rating saving

When you see the term SEER, it stands for Seasonal Efficiency Ratio but is also sometimes referred to as Seasonal Energy Efficiency Rating. It’s one of those terms where the name says it all as well, considering the rating is all about efficiency.

This standard was set by the AHRI a few decades ago as a way to gauge how efficient air conditioning units and heat pumps are. Simply put, the higher the number, the more energy-efficient a system is, which can save you a considerable amount of money down the line. That doesn’t necessarily mean you need a high SEER rating for your home, however.

SEER and Stages

SEER ratings can also be tied to the type of unit you’re considering for your home. Our buying guide explains the stages and styles, but here’s a quick refresher on how the SEER rating is connected to the stages in your HVAC unit.

  • Single Stage – A single-stage HVAC system has one stage, as the name implies. When it’s running, it’s at full capacity, and when it’s off… it’s off. Typically combined with a multispeed blower, a single stag system is in the 13 to 16 SEER range with a few exceptions.
  • Multistage – An AC system with two stages is considered multistage, which means it has two levels of output with a high and low setting. These systems are ideal for temperature control and ensure you stay comfortable all year long. Systems in this class typically range from 16 to 20 SEER and have more than two stages or variable speeds.

Systems beyond 20 SEER are popular as well and have multiple stages with variable capacity compressors. While pricey, they are ideal when you want total control over the climate in your home, although overkill for many consumers for a variety of reasons.

Maximum SEER Ratings

Often compared to gas mileage in a car, the maximum SEER rating tells you the rating of your system at its maximum efficiency. Well, while it’s nice to get able to get high mileage from an automobile or HVAC unit, it’s not going to run in that range all the time and is variable.  

A unit with a 21 SEER rating typically won’t be run at full power all the time, so the maximum number is something to keep in mind, but far from the only factor to consider. Higher SEER machines are also more expensive to purchase and maintain, as well.

What’s the best SEER rating for my home?

That all depends on your needs, but most units in the United States that are geared for residential use range anywhere from 13 to 21 SEER. If you see a central air conditioner that’s Energy Star certified, that means it meets the minimum requirements, which are 14.5. 

Does that mean you should purchase a unit with a high SEER rating to “futureproof” your heating and cooling needs? Not necessarily, given the cost of units with a high SEER rating and it also depends on where you live.

Regions that don’t have a traditional winter and arid climates would obviously want a system with a higher SEER rating whereas someone that lives in a coastal area where it’s 60 to 80°F year-round won’t require the same type of machine. If you’re unsure of how the region where you live stacks up on the SEER rating scale, this map will show the range for your region. 

ac seer region map

SEER Savings & The Payback Period

Where you live and the size of the unit you’re buying all factor into the SEER rating required for your home. That said, it’s easy to become distracted trying to find out just how much energy you’ll save along with the payback period. A large, high-efficiency unit rated at 24 SEER may not reach that payback point as quickly as you think, despite what the manufacturer claims.

One of the marketing tricks from manufacturers is to talk about how quickly your unit will pay for itself, regardless of how much it costs. While it’s true, you will save money over time by using less energy; there are a number of factors you’ll need to know in order to calculate your true savings.

How much is the annual energy cost in your home using your current HVAC system? You’ll need to know the average operating cost of your system over a 12 month period. Once you have those numbers, you’ll need to know the energy cost of the system you intend to buy as well.

Hidden costs can arise, however, including maintenance, tonnage, and all the factors we previously mentioned. If you want to find your true savings and how long it will take for the new unit to pay itself off, this SEER calculator breaks things down across a multiyear period.



As you can see, “What is the best SEER?” isn’t the easiest question to answer as it comes down to your needs, the size of the home, and where you reside. Factors like how much insulation you have in your home and the state of your ductwork are also things that should not be overlooked.

When buying a high-efficiency unit, any preexisting issues you experienced with your previous system should be addressed beforehand. If you’re curious about the cost of units from Lennox and other top brands, our pricing guides will steer you in the right direction.


Q: My current unit still runs great, should I still upgrade?

A: That depends on the year of your unit and how efficient it already is. An antiquated AC unit in an older home may have a SEER rating below 13, so a new unit could definitely make an impact.

Q: Is EER the same as a SEER rating?

A: No, but they are similar as they both deal with performance. EER stands for energy efficiency rating and tells you how a unit performs at its peak output instead of a seasonal average.

Q: How can I find the SEER rating for my older unit?

A: In most cases, it should be clearly listed on the outside of the unit. If it’s too old or too worn down to find, you’ll need to look up the make and model using the AHRI directory.

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