How Long Can You Leave A Window Air Conditioner Running?

Are you one of those people who have money to burn? Your presence here and the fact that you’re concerned about how long can you leave a window air conditioner running suggests otherwise. But that is far from being the only thing this question reveals.

It also tells us that you live in a scorching and humid environment. That it is almost impossible to turn off the air conditioner and have a comfortable indoor temperature in the area that you live. The weather outside is too hot for you to remain sweat-free under a running ceiling fan.

How Long Can You Leave A Window Air Conditioner Running?

Experts tell us that it is safe to have your window air conditioner running 24/7. No part inside the air conditioner will get too hot and melt if you keep it running all day. The performance of the air conditioner, too, won’t suffer if you forget to turn it off.

Having said that, most people still run their AC in intervals. That means that after keeping it running for, say, three hours, they turn off the AC before turning it back on in a few hours. Ever wondered why that is the case? Let us explain.

Here are four reasons why running your AC all day is a bad idea:

#1: It will consume more energy

It will consume more energy

As you might already know, air conditioners, after running for some time, achieve the temperature which you’ve set their thermostat to achieve. That causes the thermostat to send a signal to the AC to tone down, causing the air conditioner to trip. That is where things start to get costly.

As your ac alternates between tripping and running at full speed, it consumes more energy than a unit that is running at full speed all the time. That is because the latter scenario involves minimal disturbances (tripping) to the AC’s performances, whereas the former scenario is more start-stop.

Consequently, if you’re worried that your ac might drive your monthly electricity bills north, make sure to turn it off every few hours. Apart from saving you a fair amount of money, the air conditioner, once it’s back on, will run more efficiently than if you have allowed it to run continuously.

#2: It will be less efficient at dehumidifying your indoor air

Most of you will already know that air conditioners dehumidify indoor air. Those who don’t need to decipher their functioning to understand this point. Air conditioners work by taking hot air from your room, passing it over the condenser, and then expelling the heated refrigerant outside.

As they do that, air conditioners also draw in moisture from the room and thereby end up dehumidifying it. This process is crucial as it improves your comfort levels, reduces the chances of moisture-loving allergens thriving in your indoor air, and eliminate that smell that emanates from damp spaces.

The abovementioned process doesn’t happen at its most optimum level if you keep the air conditioner running all day. That is because ACs are better at humidifying when they are going at full speed – which they only do if you run them in intermittent intervals.

#3: It will hurt the environment

It will hurt the environment

There is no denying that air conditioners are bad for the environment. The hydrofluorocarbons (HFCs) that they use to bring down the temperature of the outside air before sending it into your room are one of the biggest contributors to global warming.

Does that mean you should skip air conditioners altogether to save the environment? You might not if the weather is searing out there. What you can do, realistically, is turn off your air conditioner once it has brought the temperature in your room to a comfortable level.

That is because the carbon emissions from air conditioning are dependent on the time you leave it running. While a 1.5-ton ac that keeps running throughout the day emits 5344 grams of carbon, another that runs 8 hours emits only 222g. You can do your part for the environment by turning off your AC.

#4: It might be dangerous if left unattended

Assume a scenario in which you have left your ac running before going to the office. You thought that in the hot weather that is out there, you’d be greeted by a cold room once you’re back. Little did you know that an unattended running window air conditioner can pose complications.

For instance, if there’s an electricity spike in your area when the ac was running, it could hurt its compressor. Sure, the same would happen even if you were home, but you’d then be able to turn off the air conditioner to prevent its compressor from further damage.

However, since you’re no longer home, any electricity spike can hurt the compressor and might even end up burning it in the worst-case scenario. Professionals tell us that it’s an expensive problem as the compressor is one of the most expensive parts in an air conditioner.


Running your air conditioner 24/7 won’t do any damage as long as you’re present on the occasion and have the bank balance to pay the astronomical electricity bill that will come at the end of the month. But that doesn’t mean that there aren’t any shortcomings to this approach.

As we have stated earlier, an air conditioner that keeps on churning out cold air is less efficient than one that operates in intervals. Also, it will be less efficient at dehumidifying your indoor air, leading to problems like moisture-loving allergens thriving in your indoor space.

If that wasn’t worse enough already, a 24/7 running air conditioner is bad for the environment. Its carbon emissions directly contribute to global warming and, in turn, the rise in global temperatures. That starts a cycle where the more the outside temperature goes up, the bigger will be your air conditioning needs.

Therefore, if you want to enjoy the offerings of your window air conditioner in a guilt-free manner, we recommend that you turn it off every few hours. You can get in touch with us if you need further proofs as to why this approach is better than keeping your ac running all the time.

1 thought on “How Long Can You Leave A Window Air Conditioner Running?”

  1. I have COPD and run my AC 24/7 unless it drops below 70 outside and even in the winter I have it running most of the tlme. I live in an apt. I’ve been here 5 yrs. and had 2 new ones put in because they stop cooling. I clean the filter the second I see the light. The unit is an LG not sure of the BTU wall unit. Small unit. How many hours should it last? It has to be cool or I can’t breathe.


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