window air conditioner next to sunflowers growing near home

It’s the million dollar question. Can you leave a window air conditioner on 24/7? Well, let’s get down to business and figure it out.


Real quick. If you’re here, then you’re in the same situation as many out there in this summer’s sweltering heat — wondering if it’s safe to leave the window air conditioner running all day.

It’s no lie that this summer has been one of the hottest on record and sometimes it feels impossible to turn off that window A/C unit, especially when you’re trying to fall asleep at night.

So…can you leave a window air conditioner on 24/7?

The answer to that question is: yes! A normal window air conditioner unit is designed to handle a lot of usage. If you’re at home, there is absolutely no danger in leaving your window A/C unit running the entire time.

You have nothing to worry about. Sit back, relax, and enjoy the great indoors while running that air conditioner.

window air conditioner

Now just because you can leave a window air conditioner on 24/7…doesn’t mean you should. Here’s a few reasons why it might not be such a good idea:

Be ready for some pricey electric bills at the end of the month.

It’s no secret that window air conditioners are electricity guzzlers, especially during those hot summer months. According to the Department of Energy, “set your air conditioner’s thermostat as high as is comfortably possible in the summer. The less difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.”

And remember to properly seal the space between your A/C unit and the window frame. The last thing you want is to let all that cool air escape back outside.

It will hurt the environment.

There’s absolutely no getting around the fact that window air conditioners are bad for the environment. According to the EPA, Hydrofluorocarbons (HFCs) are greenhouse gases used in a variety of refrigeration products, including window air conditioners.

But, when it comes to dangerous heat levels and your health — there’s a fine line to toe here. The best you can do is limit your usage of the window A/C unit and when buying a new unit, look for the ENERGY STAR label.

Now, when it comes to limiting your usage — here are some other tips you can try to keep cool, while not running your window A/C unit all day.

Close the doors to the room where your window a/c unit lives.

Window A/C units are made to cool a very specific amount of air space — usually one small-to-medium sized room. If you leave the door open to that room, you’re inviting warm air from the outside to come into the room. This will cause the A/C to continuously try to cool down both rooms at the same time.

If you do need to leave the door open to whatever room you’re trying to cool, limit the usage of your A/C unit during the hottest parts of the day.

Turn off your A/C unit overnight.

Most everyone you probably know runs their air conditioners overnight. And it’s understandable. Hot temperatures keep you awake and sweaty to start off the night — and no one likes that.

But there is some common middle ground here. When you’re sleeping, your body temperature naturally lowers. It can tolerate sleeping in high heat, but you just have to be asleep first!

If you have a window air conditioner with settings for “sleep mode” or “energy saver” — make sure to turn that on! That way, your air conditioner will kick off in the middle of the night when your room is the appropriate temperature. A win/win for everyone involved.

It’s time to invest in a dang good fan.

Fans don’t filter the air, nor do they cool it in any manner — but what they can do is disperse air across the room and your body, providing a ~cooling effect~ and making it seem like you might have air conditioning.

Now, let’s not joke. A fan will never replace an air conditioner entirely, but it can help boost the efficiency of your air conditioning unit. As your window unit sends cooler air into the room, a ceiling fan will continue to blow that cool air around the room.

Next time you go to sleep, try running your overhead fan through the night and give your window A/C unit a break. You might be pleasantly surprised.

Own your home? Plant some trees.

This is obviously for a very specific person who owns their home and has a reasonable amount of space around their home to plant some trees, but it’s one of the best possible ways to help cool your home in the long term.

By planting trees and other large shady plants and bushes — they could play a massive role in cooling your home in the long term future. Planting trees on the south and west sides of your home can diminish heat radiating on your home during the peak summer periods, and in return, save you money on your energy bills…all while keeping the inside of your home cooler.

window air conditioner

All in all, there are some advantages and disadvantages to leaving your window A/C running all day — but know that it’s completely safe and you have nothing to worry about.

And if you’re currently in the market for a new window air conditioner unit, here are some things you should look for!