Here in Atlanta, the summers are brutal. There’s high humidity and the temperature just feels so much hotter because of it. Summer is the worst time to be considering an AC replacement, but sometimes that’s just how it pans out. In this blog, we’re going to chat about a common question we hear at Quality Air Experts: what size AC unit do I need? Let’s jump right in.

What Are BTUs?

There are many different sizes of HVAC cooling units, and they’re categorized by “BTU,” or British Thermal Unit. This is a unit of measurement to discuss the amount of energy that is needed to, in our case, lower the temperature of water by a single degree Fahrenheit. AC units with higher BTUs have more cooling power and can more quickly get the job done for the same sized space.

Why Does AC Unit Size Matter?

So, considering this, if an 18k BTU air conditioning unit cools your 900 square foot home effectively, a 21k BTU unit could do it more quickly – but you might be spending more than you need to. Conversely, an 18k BTU air conditioning unit wouldn’t be able to keep up in your 1,200 square foot home, and a 21k BTU unit likely would be the smallest you’d want to consider. 

What Size AC Unit Do I Need?

Take a look at the following tips to help you get an understanding for what an HVAC contractor might recommend to you. These tips can get you a good understanding of why we recommend the size we do when Quality Air Experts comes to give you a quote!

#1: Determine Your Home’s Livable Square Footage

One of the key factors in determining how large of a unit you will need is how much home you have. For example, an 800 square foot house will need much less cooling power than a 2,500 square foot home. In general, you’ll need the biggest air conditioning unit offered if you have 2,000 to 2,500 square feet in your home.

#2: Consider How Many Floors You Have

As you already know, warm air rises and cool air sinks. This is helpful in the winter if you live on the second floor, but detrimental to your energy bill if your living spaces are on the second floor – like in a mid-entry home. For these homes, conditioned air is going to sink down to the lower floor, and there isn’t much you can do about it. You may consider running your circulating fans constantly in a home like this, or having two separate zones for cooling.

#3: Consider Your Home’s Insulation, Windows, and Doors

Your home’s insulation, including windows and doors, are a critical factor in determining which unit to buy. If you have old windows, doors, and poor insulation, your home is less energy efficient. In a home like this, cool air will “leak out” and you will need more cooling power to keep a steady temperature during hot Georgian summer days.

#4: See What BTU Rating Is Recommended

Keep in mind that, if you have poor insulation or odd room configurations, you might need more or less than these recommended amounts:

  • 700-1,000 square feet
    • 18k BTUs
  • 1,000-1,200 square feet
    • 21k BTUs
  • 1,200-1,400 square feet
    • 23k BTUs
  • 1,400-1,500 square feet
    • 24k BTUs
  • 1,500-2,000 square feet
    • 30k BTUs
  • 2,000-2,500 square feet
    • 34k BTUs

#5: Size Up if You Need To

Keep in mind that these numbers are just recommendations based on the size of your home. These numbers don’t take into account how well your home is insulated, the shade cover around your home, wind flow around your home, or the impacts a basement might have on the home’s cooling efficiency. We say all of this to lessen the blow if one of our technicians recommends a unit larger than you were anticipating.

Ready to Replace an AC Unit Here in Atlanta?

Atlanta summers aren’t the time to mess around with AC unit replacement – always replace your unit before it kicks the can. This can help you and your family stay safe and comfortable during our intense, humid, Georgian summers. Contact the team at Quality Air Experts today to find out how we can help you with your AC replacement this year.