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How Long Is an Air Conditioner Cycle?

air-conditioning-grillA common problem we recommend our customers look for with their central air conditioning systems in West Chester, OH during the summer is short-cycling. This is when the AC becomes trapped in start-up mode and shuts down before completing a standard cooling cycle. Short-cycling does immense damage to an AC over time because of the increased stress. It also makes it harder for the system to evenly cool the home and creates large spikes in electrical bills.

But this leads to a good question: How long is a normal air conditioning cycle? The honest answer is “it depends.”

Factors Involving Air Conditioning Cycle Length

How long a compressor must run to complete a cooling cycle relates to how much work it needs to do to properly cool your house. Let’s first assume that your air conditioner was correctly installed so it’s the right size for your home and that it isn’t malfunctioning. The length of the cooling cycle will then depend on the outdoor temperature and the level of household insulation.

On the hottest days of the year, you can expect the AC cycles to last for a long time—pretty much as long as the temperature is over 90°F and you have your thermostat set at a temperature in the 70s. If you have an older house with less insulation, a lower outdoor temperature may keep the AC cycle running for hours—until the evening cool-off or when you turn up the thermostat temperature. (We strongly recommend you have the temperature kept as high as you find comfortable so the air conditioner won’t be forced into long cycles; 78°F is a good setting to aim for.)

Fortunately, we don’t experience too many 90°F+ days in the summer, so during most of the season, you can expect the AC cycle to be 10 to 15 minutes long. This will maintain a comfortable temperature without placing excess stress on the compressor or other components in the system.

What If the AC Is Short-Cycling?

Less than 10-minute cycles for an air conditioner means short-cycling—and most likely something is wrong with the AC. No matter how you adjust the thermostat, the air conditioner shouldn’t be doing this if it’s accurately sized for the home and in good working order.

Here are a few possible causes for short-cycling:

  • AC is too large for the house: People might think there’s no such thing as too much cooling from an air conditioner. But when an AC puts out excess cooling for a space, it will shut down the cooling cycle prematurely. If your new AC is already short-cycling, the installers probably sized it incorrectly.
  • Thermostat is malfunctioning: Setting the thermostat wrong won’t necessarily cause short-cycling. A thermostat that’s broken so it’s telling the AC to shut off at odd times will.
  • Leaking refrigerant: Short-cycling can indicate refrigerant leaks in the system, which needs to be repaired ASAP.
  • Clogged air filter: See if the air filter in the air conditioner is clogged up, which often triggers short-cycling and a host of other problems.
  • Dirty coils: Either indoor or outdoor coils can become grimy, and this may lead to an AC that shuts off early.

If you suspect you need AC repairs for short cycling, or a replacement for an improperly sized AC, call us!

Bartels Heating & Cooling: “For a Comfortable Way of Life!” Call when you need AC repairs.

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