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How Long Can AC Run Continuously?

It is common on summer days for the importance of an air conditioner to skyrocket in every household where it has been placed. During most of the summer, people use their air conditioners almost daily. It’s because the outside environment is unsuitable for our health. That is why people purchasing their first air conditioner are always curious about how long an air conditioner runs continuously until it doesn’t.

According to all recent reports, modern air conditioning units function 24 hours. It’s inclusive of not showing any signs of slowing down. Hence, you can keep your air conditioner on for as long as possible. You won’t be in a hurry to switch it off any time soon.

How Long Does an AC Usually Run in a Day?

Before purchasing an air conditioner, people always look for how long an air conditioner runs in a single day. Even though no specific limits are set for an air conditioner, you can keep it on for 24 hours or extend that to seven days a week. But remember to check your thermostat while using your air conditioner.

If it is set in auto mode, your HVAC unit might not run for 24 hours and could end up stopping mid-through the cooling process. This happens because when the air conditioner knows that the room temperature has already attained the desired temperature, the compressor shuts down in auto mode.

Moreover, this compressor is responsible for the cooling done by air conditioners as it consumes about 95% of the total energy required to perform such actions. Additionally, the time your air conditioner would run will also depend upon the size of the room where you have placed it. If it perfectly fits the totality of the room, then your compressor would need to function for at least 16 hours, as it would equal 24 hours in a day.

Most of these instances are only possible when you have a central air, a window unit, or a split air conditioner ensembled in your home. But during those extreme summer days, your compressor might have to work for 90% of its efficiency, or your place would need to be warmer.

How Long Can AC Run Continuously?

The air conditioning systems are robust due to how HVAC unit professionals engineered them. Hence, you can run this unit 24/7 without stopping, as the compressor will keep providing the same energy level from starting. But in most instances, the running of your air conditioner would depend upon the type and place where you are choosing to install one.

If you don’t consider such factors while buying an air conditioner, then it wouldn’t be doing the necessary cooling as it is supposed to from the beginning. However, because of the versatility of air compressors, you wouldn’t even have to switch off your air conditioner as it can keep on carrying the work at the same energy you have started it.

The wall or window air conditioners primarily used in homes are known to function adequately for at least eight hours without switching them off. But as soon as they cross that limit, they should be given proper rest, or their efficiency would decrease significantly. On the other hand, the more oversized air conditioners generally have a longer run time as they usually take 10-12 hours after their efficiency also starts to wane away slowly.

Moreover, the run time of your air conditioner would also depend upon the number of times you switch it on and off because doing so takes a heavy toll on your HVAC unit, automatically reducing its efficiency. Henceforth, you need to adequately maintain and give timely rests to your air conditioner if you want it to run longer without being damaged and overheated midway. Doing such a thing would help you maintain the performance level of your air conditioner as it is most crucial for you.

Why is My AC Running Continuously?

Recently, after coming home, did you notice your air conditioner still running even though you switched it off long ago? Then there could be several reasons behind the occurrence. Either you need to take care of your HVAC unit properly by doing regular maintenance, or certain parts have started to lose the efficiency with which they were supposed to function.

Here are some of those reasons, summarized below, for you to understand the problem of making your air conditioner behave weirdly.

1. Thermostat Settings

One of the first things you need to do when you are faced with situations like these is to check your thermostat settings because the thermostat is the one that regulates the temperature of your air conditioner by letting you know whether the room has attained the cold temperature it is supposed to.

Moreover, only through a thermostat can your air conditioner stop producing the necessary cooling energy for your home. If it becomes faulty, lots of energy could go down the drain. The electricity bill within your house will also rise as the air conditioner can’t switch off at the necessitated time.

2. Compressor is Undersized

Suppose the air conditioner you fit in your home does not match your room’s size. In that case, the issue regarding your undersized compressor might be causing your air conditioner to function continuously because not enough cool air is generated through it. The compressor in an air conditioner’s primary function is to regulate the temperature at which the room has to be cooled.

Then, automatically switch off the device as it has already attained its target. Therefore, before placing an air conditioner, you should always calculate the load required for cooling the room. Doing these things will help your air conditioner to reduce the overall downtime and make it more efficient in terms of cooling.

3. Frozen Evaporator Coil

Suppose after switching on your air conditioners, you see that most of the air coming out of it is hot. In that case, switching off your air conditioner and calling an HVAC unit professional would be the best solution. This happened due to the air conditioner constantly running for significant periods without being switched off or given rest.

The place where the air should be coming out has been frozen, making it difficult for the AC unit to filter out cold air instead of warm air. Taking in warm air would also lead to various problems because our body can’t cool itself even though the weather outside is hotter.

4. Blocked Airflow

For instance, if you find out that your air conditioner is running continuously without producing the necessary cool air it is supposed to. In that case, the most probable thing that might have happened with your air conditioner is specific airflow blockage through its supply vents. If such a thing occurs, some debris or dirt must be stuck in the air conditioning unit, impeding the system from working.

You need to clean the air filters of your air conditioner to ensure the problem you might be suffering from is rectified in any other way. Moreover, because of such a thing, the air conditioner would keep on working without filtering the air properly from all the dirt and humidity which might be present in it. Proper temperature regulation is only possible if this problem is sorted out immediately.

5. Temperature Outside

When the temperature outside is unbearable because it is too hot and humid, it wouldn’t be entirely surprising for you if the air conditioner keeps running 24/7. In such instances, it is not easy for an air conditioner to make your home cool as a lot of energy needs to be generated to convert the hot air into cool air.

If you were expecting your air conditioner to work generally within this harsh climate outside, you were expecting something impossible. An air conditioner would take a lot of time to cool the air inside your room as the compressor needs to understand which is the perfect temperature for your place according to the settings you left in the thermostat.

6. Size of Air Conditioner

Many people might not know, but the size of an air conditioner holds great importance. It will determine whether your place will be more relaxed within a specified time frame. Supposedly, the room where you placed your air conditioner is more significant than its required capacity. In that case, it wouldn’t be possible to carry out the cooling even after it goes on for extended periods.

Whenever someone is looking to place an air conditioner in their home, it is always best to find out which type and size match the length and width of your room. If you find the correct size of air conditioner matching everything in your place, it can make your place colder within next to no time.

7. Quality of Insulation

One of the main reasons your air conditioner might have been running continuously could be due to there being a fault in your insulation. If the quality of insulation isn’t up to the mark, then it might have caused a lot of unnecessary heat to be lost during the summers.

Moreover, when the insulation is not done correctly, the heat that is supposed to be converted into cold air will not be happening correctly as all the air will leave the unit before it starts to reach your room. Additionally, a fault in the insulation of the wires in the air conditioner could also generate high pitch sounds.

They could create many problems for the people sitting close to the air conditioners. The insulation is also responsible for preventing any fire hazard from happening as the chances of it could be increased when there is a fault in the wires.

8. Dirty Evaporating Coils

Your evaporating coils could be frozen from the inside because of not insulating enough humid air outside. Your evaporating coils could also have been dirty because of needing to be cleaned for quite a long time.

A lot of dirt and debris might have accumulated inside your air conditioner, which could be why it ran continuously throughout the day.

9. Leaking Air Conditioner

After trying to find out why your air conditioner runs continuously throughout the day, if you come across a leaked pipe or insulation, it must be why your air conditioner works in such a way. It would be best to call for the services of professional people.

They are experienced in patching up the air conditioner’s leakage to rectify this damage. Only after completing this process correctly would you be able to enjoy your air conditioner in its previous condition.

10. Size of Home

If the size of your home is much larger than the air conditioner you had placed, then it is evident that your AC is taking the whole day to cool the temperature within your home. The size of your air conditioner needs to match your home as only after that wouldn’t have to take so much longer to make your place cold like you want.

Disadvantages of Running AC Continuously 24 hours Per Day

Even though it has been said that keeping your air conditioner on for extended periods doesn’t cause any harm to your body and mind. But if you continue doing that for prolonged periods without stopping, then the things you might have to go through could create many problems for your body.

That is why we have summarized a few disadvantages running an air conditioner continuously throughout the day could cause your body.

1. Lethargic

There have been many instances when people have chosen sleep over any work they might have in hand because of being under the effect of an air conditioner for too long. People exposed to air conditioners daily while in the office or at home have much higher chances of becoming lethargic than those around.

2. Getting Dehydrated

If you are familiar with the air conditioner process, you might already know that people who sit for long periods in such a room tend to get dehydrated quickly. The air inside the room starts to dry as most of it gets cooled down while being converted into water droplets.

Staying exposed to dry air for long periods could cause a lot of harm to your body as soon as possible. You wouldn’t be able to breathe properly while getting dehydrated at the same time.

3. Becoming Itchy Skinned

An air conditioner doesn’t provide you with the natural air blowing outside. Most of it is converted through supply vents in its unit. Moreover, exposure to such air for longer periods could make your skin dryer. It’s because your body starts to get dehydrated soon enough.

In such instances, your skin would also become a lot itchier than it was previously. It happens because most of it is due to being dry-skinned for more extended periods.


In this article, we have covered everything you need to know regarding your air conditioner functioning for extended periods without shutting down automatically. Most air conditioners have a compressor that lets the AC know when to stop generating cold air.

The temperature within the room might have already attained the target it was supposed to. Some disadvantages come alongside when an AC keeps functioning throughout the day. It could create many problems for our bodies.

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