Understanding Air Conditioner Efficiency Ratings

Air conditioning absorbs more than six percent of all electricity generated in the United States each year, costing homeowners billions of dollars. As a result, understanding air conditioner efficiency ratings is vital to your home. 

Understanding Air Conditioner Efficiency Ratings

Your air conditioner cools your house by transferring heat from inside to outside. Then, the compressor motor consumes the majority of the energy needed to accomplish this. In comparison to the compressor’s energy consumption, the air conditioner generates about three times the cooling efficiency.

To understand air conditioner efficiency ratings, there are a few important things you’ll need to know.

Understanding air conditioner efficiency ratings

Air Conditioner Seasonal Energy Efficiency Ratio

The most common measure of AC unit efficiency is SEER, the Seasonal Energy Efficiency Ratio. You’ve likely seen the SEER mentioned on the bright yellow “EnergyGuide” stickers that are found on appliances such as refrigerators and water heaters, as well as air conditioners. 

SEER is a measure of how much cooling is output over the course of a cooling season divided by the required energy input over that season. The higher the SEER number, the more efficient the air conditioner. However, just as ‘miles per gallon’ is used to compare car efficiency, SEER allows you to compare the energy efficiency of various AC units.

As of January 01, 2023, air conditioners sold in California must now have a minimum SEER rating of 15. However, higher efficiency units of 18 and even 26 SEER are available. A higher SEER unit will not blow colder than a lower SEER unit. Thus, a high SEER rating means that the air conditioner will deliver the same cooling power for less money. For example, a 16 SEER system can save an estimated $2,000 in annual operating costs.

Other AC Efficiency Ratings to Consider

Depending on your climate, you may want to consider other efficiency rating measures. For example, we recommend looking at the Energy Efficiency Ratio (EER) as a better guide for air conditioner energy ratings in Sacramento and Folsom. The EER is calculated assuming a steady outside temperature of 95 degrees Fahrenheit, while SEER is calculated using a temperature range of 65 to 104 degrees Fahrenheit.

EER is a better air conditioning efficiency rating standard to use in areas that tend to be very hot—95 degrees or higher—for long periods of time, as EER gives a sense of how well an AC works at peak operating conditions. On the other hand, if the average summer temperature in your area is between 80 and 90 degrees, then SEER will be more relevant for you.

What Is a Good EER Rating?

For central air conditioning units, you want to look for an EER rating of at least 12, which is much higher than the typical window AC unit efficiency rating of 8.5 EER. Just like when using SEER, the higher the EER rating, the better the AC efficiency rating.

Unfortunately, you cannot directly compare SEER and EER; they have different calculation parameters, and you will not be comparing apples to apples. 

Dehumidifying Indoors

If you live in a hot, humid climate, our Sacramento air conditioning replacement team needs to consider how well a system can dehumidify indoor air.

We perspire to provide natural cooling through the evaporation of perspiration from our skin. Drier air, up to a point, improves the comfort you experience indoors. Generally speaking, air conditioners for homes in and around Sacramento should be designed to create a 40 percent to 60 percent relative humidity in your home.

There’s No One-Size-Fits-All Efficiency Rating

There’s no ‘best’ SEER rating for everybody. Your individual AC operating habits, the size of your home, the condition of your home’s ductwork, and your personal savings goals all have a role in determining the optimal system efficiency choice for your air conditioning system.

If you have questions about how to select an air conditioner that’s ideal for your home, contact Gilmore Heating, Air and Plumbing. We offer free AC consultations and can perform the measurements and calculations necessary to find the unit that will save you the most money while providing the level of comfort you desire.

Editor’s note: This post was originally published in June 2018 and has been completely revamped and updated for accuracy and comprehensiveness in January 2024.

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