What is SEER?

It’s easy to tell by an air conditioner’s SEER rating just how efficient it is compared to others with lower or higher ratings, but what exactly do those numbers mean when it comes to staying cool during hot weather? And, maybe more importantly, paying the energy bill later for the indulgence of comfort?

SEER is a reference figure set by the Air Conditioning, Heating and Refrigeration Institute (AHRI), a trade association created in January 2008 by the merger of the American Refrigerant Institute and the Gas Appliance Manufacturers Association. One of the chief responsibilities of the AHRI is to set and certify technical standards, and in their standard ARI 210/240 “Performance Rating of Unitary Air Conditioning and Air Source Heat Pump Equipment” they defined the Seasonal Energy Efficiency Ratio in an effort to make an across-the-board guide for easy efficiency comparison between units.

According to the AHRI, the SEER rating of a particular unit is taken over the duration of an entire typical cooling season — as opposed to EER without the “Seasonal” part which only makes a single measurement — and is its cooling output in BTUs divided by the total input of energy in watt-hours during the same time period. That means the higher the SEER rating is, the more efficient the unit is … but how exactly does SEER work?

Consider a 15,000 BTU air conditioner operating at 1,500 watts 8 hours a day for 60 days. Multiply the 15,000 BTUs by the 8 hours a day and then again by the 60 days for the total BTU output for the two months. Then divide that figure (you should have gotten 7.2 million) by 1,500 watts, divide by 8 hours a day, and divide by 60 days. The final answer — 10 — is the SEER rating.

So basically SEER is an efficiency average over the entire length of time the air conditioning unit will be used during a typical season. The formula can also be used to find unit BTUs when both the watts and SEER rating are known, or the watts when the BTUs and SEER rating are known simply by adjusting the placement of the variables in the equation.

But let the professionals do the tough math — check out the AHRI-established SEER ratings on the units to compare their energy efficiency and whenever you have the need for expert advice, call Family Danz – we will be happy to help.