What Size BTU Air Conditioning Do I Need for My Home?

You’ve decided it’s time for a new air conditioner. As you look through new models, you’ve probably wondered, how much energy do I need? That’s a great question. If you don’t get an air conditioner that’s powerful enough, it won’t be effective. On the other hand, you’re just wasting energy if you buy an AC with more BTUs than you need.

What Are BTUs?

BTU stands for British Thermal Unit. It’s a unit of measure, but that doesn’t really answer the question, “what are BTUs?” in any useful way.

Here’s an example. Imagine that you have one pound of water. The amount of heat it takes to raise the temperature of that water by one degree Fahrenheit is a single BTU. Think about lighting a match. That puts out about one BTU of energy. It may seem strange, but this is also the form of measurement used to determine how many square feet of space an air conditioner can cool. 

How Many BTUs Do I Need Based on the Size of My Home?

Ideally, your air conditioner should have 20 BTUs for each square foot of living space in your home. Of course, if you’re looking at air conditioners, you know that they give off thousands of BTUs. 

So the best way to calculate exactly what you need is to find the square footage of the living space in your home, and multiply that by 20. If your home is 1000 square feet, you need 20000 BTUs. What if you just need to cool a small room with a window unit or ductless mini split? You do the same calculation. A 200 ft room would need a 4000 BTU air conditioning unit.

Keep in mind that you probably won’t find an exact match. However, this should give you an approximate idea. As a general rule, you want to choose an air conditioner with slightly more BTUs than you need, never less.

What Impacts How Many BTUs I Need?

The formula above mostly answers the question of how many BTUs do I need. However, a few other factors can impact the size of the air conditioner you need. Here are some other things that you should take under consideration:

  • High ceilings
  • Quality and rating of your insulation
  • Number of windows
  • Sun exposure

Of course, your budget is an important matter as well. Generally, the more BTUs, the higher the cost of the air conditioning unit. You might opt for lower BTUs to save some money. Before you make that choice, remember that you may have some financing options available to you.

AC Selection and Installation Help

No matter how many square feet you need to cool, we can help. The T.E. Spall & Son team will help you select an air conditioner that is the perfect size for your home and within your budget. Then, we’ll give professional installation services whenever you need them. You’ll have an air conditioner that keeps your home cool all summer long. Contact us anytime for a free assessment!

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