It’s tough to give a quick answer here, because a good SEER rating depends on what you’re looking for in a heating and cooling system.

WHAT IS SEER ANYWAY?

First, the basics. SEER  stands for Seasonal Energy Efficiency Ratio. This is the ratio of the cooling output of an air conditioner over a typical cooling season, divided by the energy it uses in Watt-Hours. It may also be called a Seasonal Energy Efficiency Rating.

A SEER ratio is calculated over an entire cooling season using a constant indoor temperature and a variety of outdoor temperatures ranging from 60 degrees to 100 plus. This is how it simulates a typical season.

Keep in mind that SEER ratio is a maximum efficiency rating, like the miles per gallon for your car. Say your car gets 28 miles per gallon on the highway. But if you’re stuck in city traffic it’s a lot less efficient. The same goes for your air conditioner. If your SEER ratio is 21, that’s the maximum efficiency and it could be lower depending on conditions.

Benefits of a High SEER Rating or Ratio

Higher Energy Efficiency
A higher SEER rating provides greater energy efficiency in certain conditions. The minimum standard SEER for air conditioners is 13, though most modern air conditioners have a SEER that ranges from 13 to 21. Trane air conditioners range from 14.5 SEER up to 22 SEER. But don’t forget — this rating is a maximum. The efficiency of your system can vary based on the size of your home, your current ductwork and other variables. Even with a high SEER rating, it’s still helpful to use other energy saving tips for the summer season. 

The U.S. Department of Energy enforces minimum SEER requirements that differ by geographical region. The minimum in the Southwest and Southeast is 14 and it’s goes down to 13 in the North. A 13 or 14 SEER rating doesn’t necessarily mean a unit is inefficient. Most older A/C systems are rated at around 8 or 9, so even the lowest available SEER rated system you buy today will be much more energy efficient.

Greater Indoor Comfort
Getting an air conditioning system with a higher SEER does mean you’ll be more comfortable in the summer months, especially if you live in a hot region like the Southeast or Southwest.

Higher SEER units often have 2 components that provide greater indoor comfort.

• 2-stage or variable-speed compressor
• Variable-speed blower

Air conditioners with lower SEER ratings are usually single-stage and only run on one speed. This means they’ll frequently turn on and off during mild weather and you’ll experience uneven cooling or hot and cold spots. You’ll also experience higher humidity levels which makes it feel hotter than it is. Your A/C needs to run for a long period of time to remove humidity from your home’s air. The ups and downs of a single-stage system don’t accommodate for this.

So what’s the answer?

There’s no magic SEER number. Anything over 13 is great. Because if you have an old 8 SEER system and replace it with a 16 SEER unit, you could significantly reduce the cost of cooling your home.

Don’t forget to look at tax credits and manufacturer’s rebates that can bring the down the cost of a high SEER system. You can also feel good using fewer fossil fuels, which means fewer greenhouse gas emissions.