Do Air Purifiers Work With Windows Open?

I love keeping my windows open at home. Letting in the fresh air and natural light into my bedroom is my favorite way to start the day. But things changed when I bought my air purifier.

I’ll be honest – I didn’t think I needed an air purifier at first. But when I checked the air quality in my bedroom and saw how poor it was, I figured an air purifier was going to be a great investment in my health. And on the first day that I kept the air purifier on, I felt the difference in air quality almost right away.

With that said, I was left conflicted with my new air purifier. To be honest, I missed the feeling and smell of the outside air coming into my room. Especially on days when it was beautiful outside and I could hear the hustle and bustle of the city below.

It was always so relaxing and it was a habit that I enjoyed, but I kept asking myself if the cleaner air from the air purifier was going to go to waste as soon as I opened the windows.

So, I did the research to figure out if my air purifier would work even if my windows are open.

And to my surprise, I learned that there are some cases where you can leave the windows open while the air purifier is on and still get clean air.

But the full answer was a bit more complicated than that.

So, in this article, I’ll share my personal thoughts as well as findings from research that I have done to help you understand whether or not your air purifier will work when the windows are open.

Read on to learn more.

Will My Air Purifier Work When the Windows Are Open?

Generally speaking, yes, your air purifier will still work and do its job if the windows are open. This is because air purifiers constantly suck in air, run it through their complex filtration system, and let out clean air free from pollutants for you to breathe.

However, it’s worth mentioning that your air purifier will work much better if the windows are closed for the better part of the day.

I personally believe that the air purifier does a much better job when the windows and doors are closed.

And it makes sense because all the air purifier will do is focus on the air present within the room without having to purify additional air coming in from the outside all the time.

But if you like to have your windows open – I don’t blame you.

Below, I will get into more detail on how to make the most out of your air purifier when the windows are open.

How To Make the Most Out of an Air Purifier When the Windows Are Open

If you really have to open the windows when the air purifier is on, then there’s a proper way to do it.

If you follow the steps that I shared below, you can ensure that your air purifier purifies as much of the air coming from the outside as possible so that you continue to breathe in air that is free from any allergens, dust, pollen, and other irritants that can impact your respiratory system.

Consider the Outside Air Quality

The first thing you need to do is think about the quality of the air outside your home.

If you live in a heavily polluted city, I’d recommend opening your windows as little as possible. This is because you’re constantly going to be letting in heavily polluted air inside your residence.

On top of that, the more polluted the air is, the harder the air purifier has to work. You want to give the air purifier an easier time so it can do its job more efficiently and last much longer.

If you bought an air purifier to stay away from the city pollution, make sure to keep the windows closed as much as possible. If you are keen on opening the windows now and again, I’d recommend you do it during the night when the air is generally much less polluted.

With that said, you may be able to open the windows while the air purifier is on if you live in a less polluted area. This is because the air won’t have as many pollutants, so it won’t stress out your air purifier as much.

If you live in a rural area – keeping your windows open and letting in the fresh air in the morning and the evening will actually be good for you – and all the air purifier will do is make sure that pollen and other irritants are not present in the air you breathe indoors.

Figure Out How Long to Keep the Windows Open For

Ideally, you should only open the windows within your home for 20 minutes in the morning and for 20 minutes an hour before bed.

That’s what I do, and it’s great.

There is no point keeping them open for longer as in that time frame – you’ve already let in as much air from the outside as you possibly could.

That way, your air purifier can get to work and purify the fresh air from the outdoors and keep it clean until the evening and throughout the night.

If you leave your window open the entire time your air purifier is on, you defeat the purpose of the air purifier as it will never be able to catch up and keep the quality of the air in your indoors at 100%.

Set Your Air Purifier to the Right Setting

Lastly, I’d recommend putting your air purifier on the strongest setting while the windows are on.

This is how you get the machine to suck in as much polluted air as possible and really cleanse whatever air comes in through the window.

When I tried opening the window with my air purifier on the lowest setting, it felt like I was breathing the same air as I would if I were outside.

But when I put it on the highest setting and moved the air purifier closer to the open window, I found that the air purifier was working much better and I could actually feel the difference in the quality of air.


Air purifiers are a great investment that everyone should consider – regardless of whether you live in the city or in a more rural part of the country.

Air purifiers can help ensure you breathe clean air at all times inside your home.

Ever since I have gotten mine – I’ve noticed a range of different allergies completely disappear.

However, keep in mind that you need to use them properly to get the most out of them.

And if you ask just about any expert, they will gladly tell you that if you want your air purifier to work, it’s best to keep the windows closed.

While opening the windows won’t stop the air purifier from working, it will constantly have to purify new air that is coming from the outdoors, which means that you are minimizing its effectiveness.