If you’ve been shopping for an AC system lately, you’ve probably seen or heard the term, SEER. But what’s a SEER, really, and how much should it influence your buying?

First, you know that an air conditioner is priced partially on SEER ratings. So a SEER-23 will cost more than a SEER-13. That’s a given.

But why? And how much more should you pay, just to get the best SEER?

SEER stands for Seasonal Energy Efficiency Ratio. It’s supposed to be like MPG in cars— a measure of how many miles you can travel on a tank of gas. Except in this case, it’s how many BTUs of cooling your AC will give you per energy dollar.

You can do some calculations to figure out how much electricity the system will use. Divide the BTU’s of your system (you can find that number on the tag) by the SEER rating. Then figure out how many hours you use air conditioning in an average year. (To save a little time, Floridians run the AC about 2,500 hours per year.) Then multiple the Kwh your AC uses per hour times the number of hours it runs annually to determine your annual Kwh consumption.

Here’s an example: You have an 18,000-BTU system that is SEER-15. (18,000 / 15 = 1200)

Divide the 1200 by 1,000 to get the answer in kilowatt-hours, which is how your utility company measures electricity. (1200 / 1000 = 1.2) Then multiply that number (1.2) times the number of hours your system runs annually. (1.2 X 2,500 = 3000.) That’s your annual consumption in Kwh.

If you check your electric bill, you can see how much your utility charges per Kwh (about 10-12 cents in Florida) and you know how much you spend on AC each year. (For Floridians, it would be $300 if we assume you pay 10 cents per Kwh.)

Now when you plug in different SEER numbers, you can see the impact SEER has on your wallet.

SEER-15: $300

SEER-18: $250

SEER 21: $214 (rounded)

SEER 24: $187.50

Because it costs less to operate, you will pay more for the higher SEER equipment. The question is, will the operating cost be low enough to justify a higher purchase price? To get the answer, you’ll have to divide the purchase price by your annual savings over the life of the system.

So if you pay $4,000 for the equipment, divide it by your annual savings to find your payback period in years.

The bottom line is, air conditioning technology has improved tremendously over the past few decades. If your AC system is 10 years old, you could probably save a bundle by upgrading— no matter what the SEER rating. (By the way, government mandates ensure that today’s systems are at least SEER-14.)

Of course, nothing is as simple as it seems. In addition to SEER, you’ll want to consider other features of a new system, such as noise level, dehumidification, cost of installation and your contractor’s recommendation. But at least you won’t feel you’re getting a snow job when the contractor or the manufacturer throws around SEER numbers.

Considering a new air conditioning system? Call www.OldsmarAC.com today at (727) 513-7227 to schedule a free in-home equipment estimate.