When you’re shopping for a new central air conditioning system, you should buy the most energy-efficient equipment you can comfortably afford.
But don’t rely on stickers that claim a unit is “energy efficient.” Knowing the SEER rating will help you judge just how energy efficient an air conditioner is.
So what is SEER? SEER stands for Seasonal Energy Efficiency Ratio. It’s a measure of fuel economy, much like “miles per gallon” for your car. The higher the SEER of your air conditioning system, the more efficient it is.
If you have an old system and you upgrade it to one with 14 SEER which is the current minimum rating allowed (as of 2015), you will most likely be more comfortable in your home, and your electric bills will be lower during air conditioning season. A 16 SEER system could be even better in your home. Check with your utility company as SRP and APS offer rebates on some of the higher efficiency systems.
You can get a/c systems with higher SEER ratings; in fact, they go all the way up to 26 SEER. But don’t do it without updating your duct work. Even the most energy-efficient unit will underperform if you couple it with bad ducts.
Consult with a trusted air conditioning professional before you select your new a/c system. Consider the level of energy efficiency that’s important to you, and whether you can afford to buy both a new air conditioner and new duct work. It could be better to put in a 14 SEER unit and fix your duct work than to buy a 19 SEER a/c and lose the extra efficiency through bad ducts.