How Long Can You Leave a Window Air Conditioner Running? You’ll Be Surprised!

If central air is not an option for you, then a window air conditioner could be a great alternative. In the hot summer months, I understand how desperate you are for cool air, and it is not uncommon for you to wonder if you can leave your window air conditioner running all day.

Yes. You can use your window air conditioner for as long as you want without causing any damage. However, in many cases, this may not be a good idea because it will consume a lot of electricity, increase tear and wear, and shorten the interval between each maintenance.

I will detail more surrounding this topic, so keep reading. Hopefully, you will understand how long you should run your window AC according to your own situation.

Ready? Let’s get started!

Is it safe to leave a window air conditioner on all night or all day?

No matter which type of appliance you are using, safety is always one of the primary concerns. Because the window air conditioning unit is powered by electricity, many people worry about if it will catch fire or cause serious issues if it runs too long.

Luckily, window air conditioners are made to run 24/7. The compressor, fan, and other parts will not overheat or melt when it runs for more than a certain period of time. Even if the compressor is overheating, it will turn off automatically as a protection mechanism.

That is to say, you can leave it on all night or all day safely. 

However, you should make sure your machine is in a good state. For example, it doesn’t make any weird noise. Otherwise, you should fix it before leaving it on.

See also: can you leave a portable air conditioner running all day?

How long can a window AC run continuously?

Since running a window AC continuously is generally safe, you can run it for as long as you want. However, there is one thing that may force you to shut it off from time to time. That is cleaning.

dirty window ac coils

The air in and outside our house is not as clean as we feel. It contains numerous contaminants, some of which will accumulate in your window unit. Air filters, evaporator coils, and condenser coils are the common residence of these dust and dirt.

When these internal components are clogged, your window AC is prone to overheating and freezing, which will eventually cause your machine to shut down.

Many manufacturers address this issue by including a filter reset indicator on the panel to remind you to clean it. For example, the indicator on LG window AC units will illuminate after 250 hours of operation. In this case, you should turn off your machine and thoroughly clean the filter. 

As for the coils, cleaning them every few months should be adequate unless your house is very dusty. 

Possible disadvantages of leaving a window AC running all day

Although running a window AC continuously is not problematic, it doesn’t mean you should do so. There are some possible drawbacks you should be aware of.

High utility bills 

Air conditioners, including window units, are energy-sucking monsters. While the energy consumption after reaching the set temperature is much lower than when it is turned on, it will still cost more compared to turning it off entirely for a few hours. 

So, you need to calculate how much time you spend in your room. If you work a 9 to 5 job, keeping your window AC running at home can cost you a lot of money. But it is not recommended to turn off your machine if you only leave your home for 1 or 2 hours. 

More tear and wear

As you know, a window unit can last more than one decade. However, things can be different if you continue to run it 24/7. The parts will wear out faster as a result of the increased mechanical tear and wear.

But it would not be a big idea if you are fine with replacing your machine every few years. 

Increased time on cleaning maintenance 

As the fan continues to pull in the air, more contaminants will land inside your appliance. This shortens the interval between each cleaning. 

Aside from that, you may need to replace some of the components more frequently due to increased tear and wear, which will take time as well.

Impact on the environment 

I don’t want to bore you with too many details. But continuing to run your AC when you are not at home can consume more energy, putting a greater strain on our environment.

How to save energy if I keep my window AC running all day?

You may have to leave your window AC running all day if you are a pet owner. But you are feeling the pinch with your finances or want to do something good for the environment. What can you do?

Activate ECO mode 

Eco mode is a feature that focuses on saving your energy. When you turn it on, it will turn off the fan when the desired temperature is reached, raise the temperature when you are not at home, and even adjust the temperature according to the sunlight intensity.

Use an inverter unit

More and more people nowadays opt for inverter air conditioners. This is due to the fact that this type of air conditioner is much more energy-efficient.

Instead of turning on and off, inverter air conditioners will run at a low capacity when the room cools down. This will save a significant amount of energy because air conditioners need a lot of electricity when turning on.

Maintenance regularly 

Dirty filters and coils can impair the efficiency of your window AC because it needs to work harder to draw air. If you want to improve the energy efficiency of your machine, you need to commit to regular cleaning. 

Sum up 

With any luck, this article has helped you decide whether you can or should run your window AC continuously.

While running a window AC 24/7 is OK, it will lead to high electricity consumption, reduced lifespan, and more maintenance. 

At last, if the only reason you want to do so is to have cool air when you return home, there is a solution. By using a smart window AC, you are able to activate your window AC in advance via a smartphone App.

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.