If you've noticed that your old air conditioner isn't performing as well as it should this past summer, it might be time to replace it. But you have to size it correctly because the wrong size won't work efficiently. An air conditioner that's built to cool a home that's smaller than what you have is obviously not going to be strong enough to get everything cool without a lot of struggle. But going in the opposite direction and getting a bigger AC unit isn't much better.

Too Small

You want to get a unit that's bigger than what you have now in only one situation: When the one you have right now is already undersized. Maybe it was properly sized when the house was constructed, but you built an addition to your home and tried to connect it to your current AC system, for example. Or the unit was undersized to begin with. In any case, this is one time when going bigger is best.

Too Powerful

If you get a unit that's built to cool a house that's much larger than what you have now, you'll certainly have a powerful unit that cools the house quickly. But that means the unit will cycle off very quickly. That will not give it time to dehumidify the house properly, because remember, the AC functions as a dehumidifier, too. That might not be a problem in dry regions, but add in a little humidity, and your place will continue to feel warmer and more uncomfortable than usual because the unit won't have time to condense the moisture and remove it.

The result is that you end up turning the thermostat down more to cooler temperatures to get that cooler feeling. That uses more power and adds higher costs to your utility bills very quickly. It also causes you to go in the reverse of conserving power. On very hot days when the electrical grid in your region is stressed, you would have a tougher time conserving power unless you decided to just be uncomfortable that day.

Too Stressful

If you're running a large AC unit at a cooler temperature than normal, and it's cycling on and off more often, you're also stressing out the unit more than usual. That will wear down the parts and require more and more maintenance on a more frequent schedule.

You are much better off getting a good air conditioning repair and installation company to come out and properly size the unit and home. Don't worry if the unit you eventually get is made to cover a range of square footage that extends a little bit past your house's size; a few square feet isn't an issue. If it exceeds it by many square feet, though, then you need to look at smaller units. But a good air conditioning company like Bryant Air Conditioning, Heating, Electrical & Plumbing will be able to provide the proper size of air conditioning unit for your home.