Problems With Oversized Air Conditioners
Is your air conditioner too big?
It is likely that you will notice at least one of the following three problems if your air conditioner is too large for your home:
- It starts and stops abruptly
- Humidity isn’t being removed by your AC
- Your energy bills are higher


- When it’s hot, does your AC cool your home in 10 minutes or less? You might have an oversized air conditioner if that’s the case. An oversized AC will cool your house quickly then shut off, which raises your energy bills and wears out your AC (from all the starts and stops).
Indoor humidity levels should be around 30–50% with a properly sized AC. You’ll need a normal-length cycle for your AC to dehumidify your home. As we explained in the first problem, an oversized AC cycles on and off a lot. If your AC keeps shutting off, it won’t run long enough to remove moisture from your warm house. That could mean your AC is too big if your home feels really humid.
Often, an oversized AC will cool your home really fast, then shut off. That wears out your AC components and raises your energy bills. Basically, your AC has a bunch of motors that run different parts (like the compressor and blower). All of these motors draw more power when they start up than when they’re running. When your AC turns on and off frequently, its motors are using more power than they should, which raises your energy bill. If your energy bills keep going up, you might have an oversized air conditioner.
How'd you get in this mess?
It’s probably because the tech who installed your AC didn’t do a cooling load calculation. Cooling load calculations take into account things like:
- You’re home’s square footage
- How many rooms you have
- How many windows and doors you have
- Your climate
- Your home’s insulation
- How’s your ductwork?
- Does it leak?
- Plus a lot more
All of these factors are taken into account when a tech recommends an AC size for your home. Unfortunately, many HVAC techs either don’t know how to do a cooling load calculation or they just skip it.
What makes a tech skip a cooling load calculation? Let’s say your old AC is 3 tons. Your tech might suggest simply replacing the 3-ton AC with a new 3-ton. What if your old 3-ton unit was already too big? If you replace an oversized unit with another oversized unit, you’ll still have the same problem.
What makes a tech skip a cooling load calculation? Let’s say your old AC is 3 tons. Your tech might suggest simply replacing the 3-ton AC with a new 3-ton. What if your old 3-ton unit was already too big? If you replace an oversized unit with another oversized unit, you’ll still have the same problem.
If your air conditioner is oversized, what should you do? Contact a professional AC contractor to inspect your AC and perform a cooling load calculation. Only then will you know if your current AC is oversized. Airy Time is located in Lebanon, Indiana the county seat of Boone County, and serves communities throughout Central Indiana.
Service Areas
- Amo
- Avon
- Brownsburg
- Clayton
- Danville
- Lizton
- North Salem
- Pittsboro
- Plainfield
- Stilesville
- Arcadia
- Atlanta
- Carmel
- Cicero
- Fishers
- Indianapolis
- Noblesville
- Sheridan
- Westfield
- Alamo
- Crawfordsville
- Darlington
- Ladoga
- Linden
- New Market
- New Richmond
- New Ross
- Waveland
- Waynetown
- Wingate