What Do SEER HVAC Ratings Mean? Understanding AC Energy Efficiency

Tony Carrick
Written by Tony Carrick
Updated April 5, 2023
Air Conditioning Unit
Photo: Tetra Images / Getty Images


  • SEER stands for Seasonal Energy Efficiency Ratio.

  • Efficient AC units have a SEER between 15 and 20.

  • You’ll pay more for an AC unit with a higher SEER. 

  • Tax credits and rebates are available for people who buy efficient AC units.

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While there are many factors to consider when you get ready to replace your AC unit, one thing you’ll definitely want to pay attention to is its SEER. Your AC unit uses more electricity than any other appliance in your home. If you want to reduce the amount of money you shell out to cool your place of refuge, pay careful attention to SEER HVAC ratings when choosing a new AC unit.

What Is a SEER Rating?

SEER is an acronym for Seasonal Energy Efficiency Ratio (also sometimes called Seasonal Energy Efficiency Rating), which is a measure of an air conditioner’s ability to do more work cooling your home while using less energy, aka its efficiency. Manufacturers are required to put a SEER on most types of air conditioners, including central, mini-split, and window air conditioning units (portable AC units currently don’t have a SEER). Heat pumps also have a SEER for their cooling function, but they follow a different efficiency rating for their heating mode. 

The Environmental Protection Agency (EPA) uses SEER to determine the minimum efficiency standards that manufacturers must meet each year with their air conditioners and which AC units earn an ENERGY STAR rating for efficiency. 

How Is SEER Calculated?

Without getting too technical, professionals calculate AC SEERs by taking the cooling capacity for a given unit and dividing it by the power used, also known as the total electric energy input. The higher the number, the more efficient the air conditioner. 

Behind the SEER is a lot of math to tell you that a higher number means you’re going to save more on your electric bills each month. So let’s dive into exactly what that means and the important changes you should be aware of within the SEER system. 


SEER2 is the new version of the SEER HVAC rating that replaces the original as of January 2023. While SEER2 uses the same formula to calculate an air conditioner’s efficiency, the laboratory testing conditions used to determine that rating have changed to better reflect a real-world environment. In short, the efficiency testing process is now more rigorous. 

Now, all manufacturers must list a SEER2 rating on their air conditioners. If you’re trying to compare the SEER on an AC unit made before 2023 with a new one, you’ll need to adjust the SEER of the old unit down about a half point to get an apples-to-apples comparison (a SEER2 rating is 4.7% lower than a standard SEER). For example, a central air conditioning unit with a SEER of 14 would have a SEER2 of 13.4. 

Why Do SEER HVAC Ratings Matter?

If you care about how much money you’re spending each month to cool your home in the summer (who doesn’t?), then you should pay careful attention to the SEER on an AC unit, as it offers the best means of determining how much you’ll spend on operating the air conditioner. Essentially, the higher the air conditioner’s SEER, the less you’ll spend on electricity to cool your home. 

That said, SEER won’t tell you exactly how efficiently the air conditioner will operate in your home. Professionals determine these ratings in labs that don’t account for old drafty windows, children who leave doors open, record heat waves, and all the other real-world variables that impact a normal home’s HVAC system. 

What Do SEER Numbers Mean?

Here's what the different SEER numbers mean:

  • SEERs of 13, 14, and 15 were the minimum ratings required nationwide before SEER2 went into effect.

  • Minimum SEER2 ratings range from 13.8 to 14.3.

  • An efficient SEER tends to fall between 15 and 20.

  • Above-average SEERs are anything greater than 21.

Keep in mind: Some units have a high SEER but do not perform at that level all the time. This is because SEERs represent the maximum capabilities for that appliance. Not all units consistently measure up to their SEER, so it’s always worth looking at the average performance of an individual unit before making a purchase.

Either directly contact the manufacturer for the specifics of that unit’s performance or get in touch with an energy auditor to inspect your home to ensure that your new AC unit will perform at its maximum efficiency.

What Is a Good SEER HVAC Rating?

Today, a good SEER really depends on what you need to live comfortably in your home. Any new unit that’s replacing your old, outdated HVAC unit is an improvement. However, if you live in a hot and humid region, you’ll want a unit that performs above average to keep your home cool. Conversely, if you live in the northeast, you can likely get by with a lower rating.

EnergyGuide label
The EnergyGuide label helps identify high-efficiency A/C units. (Photo courtesy of Energy Star)

How Do I Find My Air Conditioning Unit's SEER?

The federal EnergyGuide label can help homeowners determine a unit’s SEER at a glance. Stores prominently display the label beside each unit along with a range comparing it to other units. If you want to find the rating for an older system, go to your favorite search engine and type in your model and the year it was made (you can usually find this on the unit itself) to find more information. 

The first large number you see at the top of the label is typically the SEER, and it will be labeled “Seasonal Energy Efficiency Ratio.” Underneath the number, you’ll see a scale that shows where that specific unit stacks up as far as efficiency goes. The closer to the left-hand side of the scale it is, the less efficient it is.

Benefits of a High SEER

While most people spring for an air conditioner with a high SEER to save money on their utility bills, there are other good reasons for choosing an energy-efficient AC unit. 

Lower Electric Bills

The most popular reason for investing in an air conditioning unit with a higher SEER is that you’ll pay less to cool your home. Even making a small jump from a 14 SEER to a 16 SEER air conditioner will cut your cooling costs by about 13%. 

Tax Credits and Rebates

SEER matters to utility companies and the government, both of whom want you to conserve electricity. In an effort to take pressure off their grids, many utility companies offer hundreds of dollars in rebates when you upgrade to an air conditioner with a high SEER. 

Additionally, as part of the Inflation Reduction Act passed in 2022, homeowners can get an HVAC tax credit of up to $600 from the federal government on the installation of a high-efficiency air conditioner. 

More Efficient Cooling 

SEERs aren’t just about efficiency; they’re also about comfort. Air conditioners with high SEER numbers typically use more advanced technology, such as two-stage and variable-speed cooling, to keep you cozy and comfy in your abode. 

AC units with this modern tech can better maintain consistent temperatures throughout multiple floors in your home. A unit with a higher SEER will also do a better job keeping your home cool when the temperature outside is scorching during the summer months.

Smaller Carbon Footprint

Since electricity production requires the burning of fossil fuels, the use of more energy results in more carbon dioxide (CO2), a greenhouse gas, being released into the air. According to the U.S. Energy Information Administration, in 2022, around 31% of all CO2 emissions in the U.S. came from the electric power sector. 

What does this all mean for you and your AC unit? Basically, there’s a lot of room for improved efficiency to decrease our carbon footprint when it comes to the production of electricity, and buying an efficient AC unit is a great way to help. Since high-efficiency air conditioners use less electricity, they contribute to fewer greenhouse gas emissions than AC units with lower SEERs. 

How Much Does an AC Unit With a Good SEER Cost?

If you decide to upgrade your old AC unit, one of the first things you might be asking is, “How much do AC units with higher SEER ratings cost?” In short, it varies.

Let’s take a look at a few factors that will determine the cost of a new AC unit:

  • SEER: The SEER of your new unit can affect its price significantly, with higher SEER numbers increasing the price you pay, sometimes by $1,000 or more. 

  • Features and upgrades: While conventional air ducted systems can reach a SEER of up to 21, ductless and geothermal systems can reach into the 30s, making them more efficient (and costly).

  • Installation: Another factor to consider is where you live. The average cost of AC installation varies depending on your location. Areas with a higher average cost of living tend to have contractors who also charge more for services. Expect to pay $1,500 to $12,500 for an air conditioner installer near you to install a new AC unit.

For many people, choosing a SEER is a balance of both eco-friendliness and budget. As you determine how much you can spend on a more cost- and energy-efficient AC unit, be sure to take your budget into account. In addition to AC-buying tips like considering the unit’s size, use the SEER as your guide when evaluating your options. 

The rating on the unit you choose can mean a difference of thousands of dollars. For example, jumping from a 14 SEER to a 15 can increase costs by $1,000 or more, while jumping from 14 to 17 may cost as much as $1,800 more.

HVAC Cost-Saving Tips

The U.S. Department of Energy offers online energy efficiency calculators to help homeowners predict how much money they’ll save on energy costs based on appliances with different SEER HVAC ratings. 

If you do purchase a unit with a high SEER rating, don’t forget to ask your professional about how you can take advantage of the tax credits and rebates that come along with it. These can make splurging for a one- or two-point higher SEER unit worth the cost. A local home energy auditor can also identify ways to save energy when using your AC unit and other household appliances. 

By buying a unit that's energy efficient, your entire system will last longer due to decreased wear and tear, and you’ll spend less money on electricity every month. No matter how efficient your system is, follow our energy-saving tips to use even less power (and spend less money while you’re at it). 

Allie Ogletree contributed to this piece.

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