What is EER & SEER Rating? 5 Things You Need to Know About EER

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Last Updated: 03/25/2021

If you are looking into adding new appliances into your home, you have probably stumbled upon different ratings like the Energy Star label, EER, or SEER rating, especially if you are looking to buy a new air conditioner. If you are anything like me, these ratings may stress you out.

Very few of these appliances ever bother to explain these rating systems, leaving you dumbfounded as to what they mean. Still, it is important to understand these labels, that way you can find an energy efficient appliance for your home with less electricity usage.

If you want to know about the EER, SEER, or Energy Star ratings, read on. In this article, we cover the top 5 things you need to know about energy efficiency ratios when choosing a home appliance. Let's get started!

Air Conditioner: The Home's #1 User of Electricity

There is nothing quite as luxurious as when you walk into your nice cool house on a hot summer day. However, that joy can quickly turn to despair once you see how much the cooling system affects your utility bill over the summer.

If you have ever paid electricity bills, then it is probably no shock to you that a lot of electricity usage comes from your air conditioning system or heat. In fact, the air conditioning unit is normally responsible for 12% to 27% of total electricity costs, depending on energy usage, temperature, and Energy Star categorization.

Whether you use individual room air conditioners or central air conditioners, they add up on your utility bills. That is why efficiency matters a lot when it comes to a cooling system.

Efficient air conditioner units can cool your house while using less power. This makes these air conditioners more energy efficient.

Since the air conditioner unit is the homes #1 user of electricity on average, you want to make sure that you get a model that is highly efficient. Look for air conditioning units with Energy Star ratings and high EER or high SEER ratios.

What about heating?

Obviously, heating power eats up electricity too. It’s not just the cooling unit that is responsible for energy consumption. Heat pumps, a heat system, and air source heat pumps will also affect power consumption. You want your heating system unit to have an Energy Star label too.

EER Rating vs SEER Rating

If you want to get the most energy efficient home appliance, you need to look at the EER, SEER, and Energy Star rating. These ratings tell you the efficiency of the model, though the ratings tell you different information. Typically, you will see these ratings on room air models. Let's take a close look at both ratings.

Energy Efficiency Ratio EER

Energy Efficiency Ratio EER

EER stands for energy efficiency ratio. EER is used frequently in an HVAC system to tell how powerful an air conditioner is with a certain amount of electrical energy. The higher the EER rating, the more efficient unit or efficiency equipment you have. In contrast, a low ratio means that the unit is less efficient and has less powerful cooling abilities.

Air conditioner energy is relatively easy to calculate. The EER is calculated by the cooling output, which is measured in British Thermal Units (BTU), to the electricity input, which is measured in Watt Hours. In other words, you divide the BTUs by the Watts hours.

Let's take an example to make it a bit easier to follow. Assume that you have an air conditioner with a cooling output of 12000 BTU. It consumes 1200 Watt-hours of electricity. Based on these numbers, this system has an EER of 10. You get this number simply by dividing 12000 by 1200.

If you want to know how efficient your air conditioning unit is, you can look on the side of the unit for the EER rating. Typically, this label will have the phrase “Energy Guide” at the top. An impressive EER rating will result in an Energy Star label too.

Seasonal Energy Efficiency Ratio SEER

Seasonal Energy Efficiency Ratio SEER

In many ways, the SEER, or the seasonal energy efficiency ratio, is like the EER. The only difference between these two ratings is that the SEER is calculated over the summer months, meaning that it includes a fixed and variable temperature.

For this rating, a constant indoor temperature and relative humidity are used, although the outside temperature varies. These numbers are used to simulate how the air conditioner will work throughout the summer seasons. This is different from the EER rating, which uses both a fixed indoor temperature and outdoor temperature.

Energy Efficiency Ratio vs Energy Efficiency Rating

When you first start doing research into the EER rating, it can be confusing to know what all the terms mean. I, for one, was really confused about the differences between the energy efficiency ratio and energy efficiency rating.

Even though these are two separate terms, there is no difference between the energy efficiency ratio and rating. They are simply two different titles for the same rating. You will often see these two terms used interchangeably, but there’s no need to get worried or anxious about it.

Other Terms To look Out For

There are some other terms that generally refer to the same thing. This can include efficiency rating, Energy Star, or energy savings. No matter the unit, it should be easy to find the Energy Star label if it has it.

Higher EER Ratio = Greater Savings

As you first start shopping for air conditioners with high EER, SEER, or Energy Star ratings, you may be shocked to see how much more expensive they are than other models. Despite the more expensive price upfront, you will definitely save money by buying these models.

Lower Energy Bill

A higher EER and SEER rating means that your AC unit uses a lower energy consumption and offers energy saving abilities. By using less energy, you obviously save on your energy bills. This will give you noticeable energy savings every single month.

Fewer Repairs

At the same time, air conditioners and heating units with higher ratings tend to have more advanced technology. This technology means that they are less likely to break over time. With fewer malfunctions, you can also save on repairs.

More Powerful Cooling

Still, units with high ratios also have more powerful cooling abilities and cooling equipment. This is because they offer more efficient cooling powers despite the weather. These cooling powers can make your home more of a comfort. The same goes with the heat pump and heating equipment; they too have higher efficiency for maximum comfort.

With these factors in mind, buying an air conditioner with an Energy Star rating will pay for itself very quickly. All together, buying energy efficient air conditioners will lead to greater savings over time.

Finding The Right Efficiency EER Rating For Your AC Unit

Right Efficiency EER Rating For Your AC Unit

Image Credit: energystar.gov

Air conditioners and heating units come with a wide range of EER or SEER ratings. You will want to find the best air conditioner based on your home and needs. On average, air conditioners with an EER rating of 9 or above is considered above average. Anything at an 8 EER rating or below is considered below average.

If you want the most savings per month and have more money to spend at one time, you might want to look for an EER rating as high as 12. However, an air conditioner as effective as this may be a waste of money for people who live in more temperate environments.

What matters is to compare your current budget to perspective savings. For example, those who live in more extreme environments will have greater savings than those who live in more mild temperatures. That way, you have an accurate idea of savings based on your realities.

With this in mind, you can find the perfect energy rating for your home. We generally recommend looking for a model with a rating of 8 to 10, but you can go above or below this rating depending on your home. Just make sure that your model has an Energy Star label or rating for an efficient unit.


Even though the EER and SEER ratings seem a little daunting at first, they are actually pretty easy and straightforward. The higher the EER or SEER rating, the more efficient your air conditioner or appliance will be. This may cost you more upfront, but it will save you more money in the long run.

Not only that, but models with an Energy Star rating are also more environmentally-friendly. Since they don't require as much electricity, they will lower your carbon footprint, making them an ideal choice for those with energy or money savings on their minds.

For these reasons, a new air conditioner with a high energy efficiency ratio EER, Energy Star rating, or Energy Star label is the way to go. Just by reading labels, you can easily find an efficient cooling or heating unit that saves you money, performs with high efficiency, and offers impressive cooling capacity. 

Charles Jasper

Charles Jasper is the owner and main author of Home Climate Center. He has a degree in Engineering and 20 years experience on working on HVAC systems. He has a passion for everything related to home improvement and loves to travel. When he is not working, you might find Jasper working on projects around the house or organizing a camping trip.

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