If only buying a central air conditioner were like the process of buying a pair of pants: look them over, try them on, see if you like the fit and, if so, buy them if the price is right.

Then again – believe it or not – there are some similarities between the two purchasing decisions.

While a central air conditioner no doubt represents one of the biggest investments you will make in your home, you still must consider your choices, choose a trusted air conditioning service company, assess the “fit,” and conduct a careful cost analysis.

Just as you may begin the process of buying a pair of pants by first looking to see if the store carries your size, the process of buying a central air conditioner often begins with a number of its own: the SEER rating.

You might prefer to shop for clothing alone, but if you're in the market for a new central air conditioner, it’s helpful to have both the U.S. Department of Energy and a qualified air conditioning service company at your side.

Below are some straightforward questions to help understand why the SEER rating is so important and also why – just like with pant sizes – sometimes numbers alone don't always tell the whole story.

Please give it to me in English; what's a SEER rating?

A SEER rating is a number that denotes an air conditioner's efficiency. That's the simple definition. Just like a gas-efficient car costs you less to run, an energy-efficient air conditioner costs you less to operate.

OK. I follow that. But I suspect there's more to know about a SEER rating, right?

You're right. The department of energy is typically more expansive. It says that SEER is a “measure of equipment energy efficiency over the cooling season. It represents the total cooling of a central air conditioner or heat pump (in btu) during the normal cooling season as compared to the total electric energy input (in watt-hours) consumed during the same period.”

I need some context. What SEER rating should I look for?

The federal government laid down the law on January 26, 2006, when it decreed that all air conditioners must achieve a SEER of at least 13. The previous minimum was 10, while many older air conditioners carry SEER ratings of six or less. The highest SEER rating is 25.

Where do I find this SEER rating? 

Most air conditioners carry a yellow “Energy Guide” label that clearly displays the SEER rating. It also can be found near the top of the manufacturer's label, near the model and serial number. The first two numbers tell the story. An air conditioner with a model number of “15AC,” for example, has a SEER rating of 15.

I have a feeling that the higher the SEER rating, the more an air conditioner costs. Is this correct?

In general, yes. But just like a gas-efficient vehicle usually costs more money upfront, it helps to take the long view with an energy-efficient air conditioner. The difference between an air conditioner with a 10 versus 15 SEER rating adds up to an energy savings of about 33 percent per year. Over five years, the savings add up to $540, over 10 years, $1,080,  and over 15 years, $1,620.

I've heard of air conditioning service companies that push air conditioners with sky-high SEER ratings. But other factors must be involved, right?

There is no “one size fits all” strategy when it comes to choosing an air conditioner. Your air conditioning service company should take into consideration many factors, including summer temperature trends in California, the size of a home, how much a homeowner relies on air conditioning and at what preferred temperature – a scientific calculation known as the “cooling load.” Also consider how long you plan to stay in your home.

With all of these variables in the mix, a company should come up with a recommended SEER rating. You can even check the math against the department of energy's own “energy savings calculator.”

Finally, you should be given a list of top-rated Energy Star air conditioners to choose from, so that in the end, you land on the right air conditioner that provides the right fit for you – much like a new pair of pants that you can wear with confidence. 

If you’re looking for a trusted air conditioning service company, contact Experts In Your Home!