Does the Air Purifier Need to Be On 24/7?

Buying an air purifier is exciting. I remember when I got my first air purifier and turned it on for the first time. Within just a few days, my allergies when indoors almost disappeared and it literally changed my life.

But as you start to use your air purifier, you might start to wonder if it needs to be on around the clock.

I personally didn’t do that in the beginning because I thought it was a waste.

With that said, I’d like to come forward and say it was a pretty big mistake – at least for me.

So, if you’re wondering if you should be keeping your air purifier on around the clock – I will help you decide that for yourself in this article.

Not only that but I will also help you find out how long it takes for an air purifier to clean the air in a room, why I personally think you should keep the unit on 24/7, and tips for making the most out of your new purchase.

Should I Keep My Air Purifier On 24/7?

Yes, I highly recommend keeping your air purifier on 24/7. I know it might sound like a waste but it isn’t.

When I first got my air purifier over four years ago – I had the exact same feelings about running my air purifier around the clock but after feeling the benefits – it simply didn’t make any sense for me to turn it off at all.

If my opinion doesn’t quite satisfy your expectations – I want to point out that air purifiers are actually made to stay on all the time.

Manufacturers know that purifying the air in any given room or home is no easy job and in order for the air purifier to do its job properly – it needs to be on for as long as possible. That especially applies if you live in a heavily polluted city and open your windows all the time.

Aside from that – it’s worth noting that most high-quality air purifiers have air quality control sensors, which can detect if the air within the room is clean or not.

That way – if the air purifier has been on for two hours and the sensors notice that the air is as clean as possible – they will actually turn the air purifier off and the second the air quality drops – the air purifier will start up again.

In essence, the air purifier isn’t actually going to be running 24/7 but rather when and if needed. And of course – these types of air quality control sensors aren’t available in every air purifier but rather only in the more high-end models.

How Long Does It Take an Air Purifier to Clean the Air?

If you leave all the doors and windows closed in the room when you turn on the air purifier, then it can cleanse most of the indoor air in around 45 minutes to an hour. However, this can vary depending on the size of the room, purification capacity, and setting you leave your air purifier on at.

If you constantly have your windows or doors open, then the air purifier will never quite get to cleaning 100% of the air within the room as a lot of unpurified air will be entering the room from the outside.

I have a medium-sized bedroom. My air purifier also has an air quality control sensor and if the fan is on the highest setting with the windows closed – the air purifier turns off after around 55 minutes.

Why You Should Leave Your Air Purifier On 24/7

So, now that you’ve learned that it’s actually best practice to leave your air purifier on 24/7 – it’s time for me to explain why. Don’t worry; I was skeptical at first too. It didn’t make immediate sense in my head that I should leave my air purifier on all the time, but after doing the research and trying it myself, I was quickly proven wrong.

Now that that’s out of the way, it’s time for me to get into the details of why you should leave your air purifier on 24/7.

They Are Designed That Way

The primary reason I recommend turning your air purifier on 24/7 is purely because they are designed to be used in this manner. Most modern air purifiers work best when they’re constantly on, so if you are turning your air purifier off to preserve it – you aren’t actually doing anything but preventing yourself from breathing the cleanest possible air.

So don’t worry, the motor or the fan will not get damaged because of constant use. The only thing you will have to do more regularly by having your air purifier on all the time is clean the filter more regularly because it will quickly start to build up layers of particles, which would have otherwise ended up in your lungs.

It Doesn’t Consume That Much Energy

Another advantage of keeping your air purifier on constantly is that it will consume less electricity. This is one of the arguments that had me scratching my head because if I’m being honest, this doesn’t make that much sense at first.

Don’t air purifiers only consume electricity when they are on?

Well, yes this is true. However, if you turn your air purifier on and off at random intervals, you might end up using more electricity because the air purifier will have to start purifying all of the air all over again rather than just taking care of any unpurified air within your space at any given moment.

And of course – it’s worth paying attention to how much electricity your air purifier uses. If you make use of a modern real HEPA filter air purifier, chances are that it’s not that much but if you’re using an older or industrial air purifier – those can end up racking up your electricity bill quite a bit more.

Modern Air Purifiers Have an Automatic Mode

There are many air purifiers on the market that have an auto mode.

This involves a set of sensors that detects the number of pollutants in the air. If there’s a high level of pollutants, the air purifier automatically turns on and cleanses the air until the quality is satisfactory. And once the air purifier cleanses the air up to a certain level – it will automatically turn off.

This point actually ties in very nicely with the point from above. If your air purifier has an automatic mode and you keep it on 24/7, it will never have to clean the air in the entire room all at once again but rather just turn on for a few minutes when and if needed.

In other words – the air purifier isn’t actually going to be running 24/7 but only when the quality of air in the room drops below a certain level.

Modern Purifiers Have Short-Circuit Protections

Another reason it’s completely fine to leave your air purifier on is that all modern machines come with short circuit protection.

So, even if you don’t have the most reliable energy at home, your air purifier remains protected even in the event of a short circuit.

Tips for Getting the Most Out of Your Air Purifier

When I first got my air purifier – I had little to no idea how to make the most of the unit. I just knew that I should turn it on and keep it that way.

However, over the coming months and years, I learned a lot, and in this section – I’ll give you my first-hand experience as to how you can make the most out of your air purifier.

Place It in the Right Place

Your air purifier thrives the most in open space where it can suck in as much air as possible.

As a result of that, you need to make sure that your unit isn’t anywhere near a sofa, in the corner of the room, or is obstructed by other objects which are preventing it from operating to its absolute best.

As a new air purifier owner, one of the mistakes I made for a very long time was neglecting the positioning of my air purifier.

And if you’re a new owner of an air purifier yourself, I can almost guarantee that your air purifier isn’t placed in the best area of your room either.

And to be honest – that’s totally understandable as nobody wants to have a big air purifier in the middle of the room taking up all this space.

What I personally do is have my air purifier near the sofa, which is also conveniently located near the window.

Do note that the air purifier isn’t on the floor though. I have bought a designated table that has elevated the air purifier to a decent level so that it’s not obstructed by any furniture.

That way, the air purifier can both do its job extremely well and purify any incoming air when I open the windows but is also out of the way.

Close the Windows & Doors

You can leave the doors and windows open while the air purifier is on. However, remember that this means unfiltered and dirty air is always going to be entering the room.

If you want the air in your room to remain as clean and healthy as possible, I recommend closing the doors and windows to prevent new air from entering the room.

With that said, there are times when you don’t have a choice but to leave a window or door open.

If you decide to do this, we recommend placing the air purifier close to the door or window.

This allows the air purifier to suck in all the new air that enters the room right away, reducing the chances of you inhaling harmful particles from the outside.

Choose the Right Air Purifier

In order to make the most out of your air purifier – you first need to make sure you have the right air purifier for the job.

Whether you have a small or big room, I recommend getting a high-quality unit with a real HEPA filter.

Additionally, you have to make sure to match the air purifier to the size of the room.

The larger the room, the stronger the air purifier you’ll need.

If you put a small air purifier in a big room, it will not only take forever to purify the air but the unit will also struggle with keeping up.

On the flip side, getting an air purifier that’s too large for a room may result in you spending more money than needed.

So, when buying an air purifier, always take a look at the size of your room and the purification capacity of the unit you’re looking at.


No, your air purifier doesn’t need to be on 24/7.

However, if you want to make the most out of the unit and constantly breathe in clean air – then I would personally highly recommend you to keep it on around the clock.

And don’t worry – your air purifier isn’t going to sky-rocket your energy bill. They are designed to be kept on all the time and are actually very energy efficient.

On top of that – most modern-day air purifiers have air quality control sensors, meaning they will only turn on when the air quality in your room drops below a certain level.

That way, your air purifier might be on 24/7 but only actually turn on and purify the air a few hours per day.