In Austin, Texas, AC energy is often referred to with two acronyms at the forefront: EER and SEER. For those who do not know – or for those who need a bit of a refresher, EER and SEER are standards for measuring the efficiency of an air conditioning unit. AC energy efficiency has become a hot topic for us here at Alamo Austin Air Conditioning & Heating. We are always getting calls from customers looking for ways to become more energy efficiency and reduce those pesky electricity bills. The first thing we always do is mention the standards of EER and SEER. Usually, the look that follows is, more or less, a look of confusion. Are you tilting your head yet? Don’t worry we’ve got this and you, we are about to explain what EER and SEER mean – and when best to use them.


Whether you are purchasing a new AC unit or taking a peak at your current one, you should notice a bright yellow tag. The tag will boldly state “ENERGYGUIDE” and indicate a number. If your unit was made after 2006 then it should read 13 or higher. The number is a direct result of how many BTUs, or British thermal units, are used per hour for each watt. In any case, this is where and how you find the rating of your AC unit’s energy efficiency and whether it is SEER or EER. We know we’ve been throwing out these two terms, and have yet to fully explain them. Well here you are:

EER: Energy Efficiency Ratio

SEER: Seasonal Energy Efficiency Ratio

What’s the Difference?

SEER is much more common than EER, and based on a standard test across a specific seasonal temperature range. Most large central air conditioning units are rated by seasonal energy efficiency ratio. EER, which came into use before SEER in 1975, is typically used to measure the efficiency of smaller window units located in arid or hot climates (And by hot we mean hotter than 83 degrees Fahrenheit). Most technicians prefer the use of this method as it does not use additional input – such as seasons. It is more of a technical number – and thereby, in our opinion, more accurate.

Final Tips

Despite their differences SEER and EER are both were developed to measure AC energy efficiency in Austin, Texas and the surrounding areas. Neither one is better than the other, simply made for measuring different types of air conditioning units.

Whatever you choose, be sure to hire a professional to install the new unit. What’s the point in taking SEER and EER in to account, when it’s not installed correctly? Rely on the professionals at Alamo Austin Air Conditioning & Heating for that service. We provide the best AC service in Austin! For more information or to schedule an appointment, click here.