Mick's Heating and Air Conditioning Blog

Understanding EER And SEER Ratings

Many people get confused when they begin shopping for a new air conditioner. There are so many different makes and models available as well as a variety of EER and SEER ratings, making it confusing if you don’t know what to look for. Understanding the difference between SEER and EER ratings can be an important part of not only being an informed consumer, but of also getting the most energy efficient air conditioner for your particular environment.

An EER or Energy Efficiency Ratio became one of the industry’s first attempts at standardizing the calculation of the energy efficiency of a particular air conditioning unit. The EER is calculated by utilizing a single condition and calculating the amount of energy used versus the number of BTUs or British Thermal Units of cooling that is created.

Typically the EER rating is calculated by using a humidity of 50% with an indoor temperature of 80° F and an outdoor temperature of 95° F. Then, the number of watts or electrical power used is divided by the BTU or amount of cooling achieved.

Similarly, SEER ratings (Seasonal Energy Efficiency Ratio) measure the energy efficiency of an air conditioner, but it takes seasonal variances (the “S” in SEER) into consideration. SEER ratings do not utilize just one set of conditions, but instead utilize outside temperatures ranging from 65° F to 104° F. So, SEER ratings take seasonal variances into consideration, rather than just a single condition.

It is required that all air conditioners in the U.S. have a SEER rating, but there are still times when knowing the EER rating of a unit will be important. For example, while SEER is a more accurate rating of the energy efficiency of an air conditioning system given varying temperatures, homeowners living in climates that have temperatures that remain at 95° F or above, might find it useful to know the efficiency of the AC unit at those specific conditions.

Regardless of what type of air conditioning unit you are considering, paying attention to the energy efficiency can definitely be an important factor in helping to eliminate high energy bills. Additionally, when comparing units, be sure you are comparing SEER ratings to SEER ratings or EER ratings to EER ratings to get the most accurate comparison.

Give us a call to learn more about your options for efficient heating and air conditioning.