What Is The SEER Rating?

How efficiently the system does its job is another matter. Efficiency is expressed in terms of the seasonal energy efficiency ratio, or SEER. To determine the SEER, you divide the air conditioner cooling capacity by the amount of electric power it consumes, in watts (SEER = B.T.U. per hour/watts averaged over the cooling season). An efficient central air conditioning system will have a SEER of 13.0 or higher, except for units of less than 20,000 B.T.U./hour, where a SEER greater than 12.0 is considered efficient. The energy savings can be substantial. A central air system with a SEER of 12.0 will use 33 percent less energy than a system with a SEER of 8.0.

When you go shopping, you will find the SEER listed on the yellow EnergyGuide label attached to each central air unit. The manufacturer (MFG), model number and seasonal energy efficiency ratio (SEER) are listed by cooling capacity (B.T.U./hour). The larger the SEER, the more efficient the system. A few models are available with a SEER of over 15.0. All models are listed in the ARI directories, which are on file at your local public library.