How long should an AC run before shutting off?

Author: Lindsay Haley  |  Last update: Monday, November 24, 2025

When things are working right, your central air conditioner should run for 15 to 20 minutes and then turn off for a few minutes. It will do this two or three times every hour. It may run longer when it's sweltering outside.

How long should it take for AC to turn off?

As suggested by experts, the cooling cycle of an AC is supposed to last for at least 15 minutes. In this duration, the compressor and air handler distribute the desired cooling inside the room. But when this normal cycle is disturbed and reduced to 10 minutes, we can call this a short cycle that needs prompt repair.

Is it okay for my AC unit to run all day?

The constant running of your AC unit will reduce pressure in the evaporator, or cooling coil until it freezes over, according to Cool Today. This is why in some cases, this constant running can be dangerous.

How long is too long for an air conditioner to run?

In general, wall and window air conditioning units with smaller capacities can typically run for up to eight hours at a time before they need to rest. Larger wall and window units have a longer running time of around 10 to 12 hours, depending on their cooling power.

How long should an air conditioner be off between cycles?

Once the AC completes a cycle of about 15 and 20 minutes, it should remain off for 7 to 10 minutes. This helps it cool off before starting another cycle. The stops happen 2 to three times per hour.

How long should my HVAC system cycle?

How long should AC run before kicking off?

When things are working right, your central air conditioner should run for 15 to 20 minutes and then turn off for a few minutes. It will do this two or three times every hour. It may run longer when it's sweltering outside. And, much shorter cycles can mean there's a problem.

Is it normal for my AC to turn on every 10 minutes?

If you have noticed that your air conditioner has been turning on and off as frequently as every 10 minutes, your system is most likely in need of repair due to “short-cycling.” Short-cycling is when a system turns on and off abruptly and often.

How long should it take to cool a house from 90 to 72?

Cooling a house from 90 degrees to 72 degrees typically takes about 2 to 4 hours, depending on various factors.

How often should an AC turn on and off?

The system will often complete a full cycle every 15 to 20 minutes, then turn off for up to 10 minutes before turning back on. Following this process, the system should turn on and off about three times every hour. Is your system doing more than that? Perhaps it is doing so less often than you think it should.

Is it OK to leave AC running 24 7?

There are a few reasons you don't want to run your AC system all the time: System stress: Your air conditioner unit needs time to take a break. If it's running all the time, it can be damaging to the system and lead to the need for a costly replacement. Energy bills: The cost to run your AC 24/7 can be high.

Is it good to give your AC a break?

This will reduce the strain placed on your AC unit, allowing it to run more efficiently, and lowering your energy bills. Bottom line, while it's not necessary to give your AC unit rest breaks during summer, its maintenance is essential.

How many hours can AC run continuously?

If a standard air conditioner is in good order, it can run continuously without a problem. Wall or window AC units should only run eight to 12 hours before you turn them off. Running your AC nonstop will lead to higher electric bills and more repairs.

How long should an AC run to drop 1 degree?

On average, an air conditioner running in good condition should take about 15-20 minutes to drop the temperature by 1 degree in a standard-sized room. However, factors like outside temperature, unit size, and insulation quality can affect this timing.

What happens if AC runs all day?

The constant running will reduce pressure in the cooling coil until it freezes over, which is dangerous as it can cause liquid refrigerant to flood back to the compressor and damage it (the compressor is a very expensive part).

How do I know if my thermostat is bad?

7 Ways to Tell Your Thermostat Is Broken
  1. The Thermostat Has No Power. ...
  2. The AC or Furnace Won't Turn On. ...
  3. The Heater or AC Won't Turn Off. ...
  4. The Thermostat Reading Doesn't Match the Room Temperature. ...
  5. The Thermostat Doesn't Respond. ...
  6. The HVAC System Is Short Cycling. ...
  7. The Thermostat Forgets Programmed Settings.

What is the normal cycle time for an air conditioner?

Your AC unit should run its cycles for about 15 to 20 minutes, no more than a couple of times within an hour. If your AC is running for long cycles, it could also indicate a problem.

How long is too long for AC to run?

If you're like many people, you might be wondering how long your air conditioner can run without getting damaged. The answer is simple. Your AC could theoretically run for 24 hours a day all summer long without issue. Of course, the longer it runs, the more wear and tear it will experience.

Does an air conditioner need to rest?

Allowing your air conditioner to rest is an excellent way to extend its life and ensure it operates efficiently throughout the years. Air conditioners, like homeowners, require rest in order to recover and perform optimally.

What is the ideal AC runtime?

On an average summer day, a general guideline is that your AC should operate between 12 and 16 hours. However, several factors can influence this, including the outdoor temperature, desired indoor temperature, the size and type of your unit, and your home's energy efficiency.

How cool should my house be if it's 90 outside?

Some of the basics include: turn your thermostat up a couple degrees and deal with 76 to 78 degree temperatures indoors for a few days. close off unused rooms. close doors and vents.

Is 72 degrees to hot to sleep in for a house?

Sleep experts believe the best temperature for great sleep is between 68-72 degrees Fahrenheit. But in addition to making you uncomfortable and interfering with healthy sleep patterns, being too hot at any time of day or night can cause health risks like dehydration and heat stroke.

How often should AC run on a 90 degree day?

Air conditioners shouldn't generally work all the time unless the thermostat is set to “fan on” (inadvisable). A correctly sized and well-maintained AC system should run for 15 to 20 minutes, two or three times every hour—with longer cycles in the higher temperatures of summer.

How long should AC turn off between cycles?

Quality of your Air Conditioning Unit

Fortunately, most of the modern units work efficiently, so you will not have problems with long and short cycles. So, how long should AC stay off between cycles? Between 7 and 10 minutes after every cycle is ideal.

Why does my AC run for 20 minutes then shut off?

Electrical problems are a common cause of short cycling. This may indicate that there is an issue with the electrical supply line or the capacitor could be broken or failing. This can be caused by the thermostat, electrical connections in the system, or the circuit boards.

How do I know if my AC is running too much?

7 Signs You're Overworking Your Air Conditioner
  • Shocking Increases in Your Energy Bills. ...
  • Your Air Conditioner Struggles to Cool Your Home. ...
  • Your Home is Uncomfortably Humid. ...
  • You Are Wearing Out Your Thermostat Buttons. ...
  • Your House has Warm and Cool Spots. ...
  • You Hear Strange Noises. ...
  • Your HVAC System Leaks.

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