Skip to Accessibility Tools Skip to Content Skip to Footer
air purifier or humidifier for asthma

The Difference Between Air Purifiers and Humidifiers

Last summer, we had a terrible fire in our valley. For a time, it was a Priority 1 fire. And the building where I work was surrounded by smoke – and the filtration system was pulling the smoke into the building.

I needed an air purifier

I could smell the smoke in my office and knew I was in trouble. My eyes were burning, my throat was sore, my nose was running and my lungs felt like they were on fire. I used my inhaler but was still struggling to breathe. I wished I had a portable air purifier in my office like I did at home.

I quickly left the office and headed home where we have several portable air purifiers. In my family of 5, all 5 of us have allergies, and 4 have asthma. So we do all we can to keep our home allergy and asthma friendly.

I found out that every store in our county of 2,400 square miles was sold out of air purifiers! That’s how thick the smoke was from the forest fire.

Preparing for the future

Since we had a trip planned to see family in another part of the state, I decided to buy an air purifier there for my office. I knew they would have plenty of options in stock. And I could find a smaller unit that would be just right for the size of my office.

When we arrived, I asked the nearest employee where the air purifiers were. She said, “Do you mean a humidifier?” I told her no – because humidifiers just put moisture into the air. I needed an air purifier that would do just that – purify (or clean) the air. That was the first time I realized people don’t know the difference between a humidifier and air cleaner.

What is the difference between air purifiers and humidifiers?


A humidifier will add vapor or steam to the air.  But – there is a downside to using them. You can add too MUCH moisture into the air – and that can be a recipe for mold, bacteria and dust mite growth in your home.

Humidifiers also need to be kept VERY clean.

Mayo Clinic says:

“Dirty reservoirs and filters in humidifiers can quickly breed bacteria and mold. Dirty humidifiers can be especially problematic for people with asthma and allergies, but even in healthy people humidifiers have the potential to trigger flu-like symptoms or even lung infections when the contaminated mist or steam is released into the air. Evaporators and steam vaporizers may be less likely to release airborne allergens than may cool-mist humidifiers.1

Air Purifiers (Cleaners)

Portable air cleaners are made to filter the air in a single room (unlike the furnace or AC unit that cleans air throughout the house.) A portable air cleaner can’t clean all of the pollutants in a home. But, a recent study by a Utah Pulmonologist showed that using an air purifier can cut indoor pollution in half.

Like your furnace or AC unit, the filter in an air purifier has to be changed on a regular basis. And the purifiers come in different sizes to clean different sized rooms. You can learn more about air cleaners here.

Is an air purifier right for you?

If you have allergies and asthma, do a little research and see if an air purifier is right for you. Especially if you live in an area that is prone to forest fires, or a big city with lots of pollution.

I hope this clears up any confusion about humidifiers vs standing air purifiers.

Has anyone else been using air purifiers? Has it helped? Let me know in the comments below!

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

  1. Mayo Clinic. Humidifiers: Air moisture eases skin, breathing symptoms. Accessed August 2019.


  • rjmoon
    1 month ago

    I’ve been going back and forth about getting an air purifier. For awhile I was shopping around for one, then I decided it probably wasn’t necessary and not worth the money, and now I’m back to thinking it might be a good idea after all. If nothing else, I won’t need to dust and vacuum as often, and that alone would likely help. I get by wearing a mask and using my inhaler before I start cleaning, but it would be nice to minimize those tasks as much as possible, especially when my asthma’s not at its best. I think I just talked myself into it, actually!

  • Andrea M Jensen, CHES (R), AE-C author
    4 weeks ago

    Hey there!

    This is a guide from Allergy & Asthma Foundation of America. These air cleaners have been certified as “Allergy & Asthma Friendly”

    Good luck!
    Andrea (author)

  • Leon Lebowitz, RRT moderator
    4 weeks ago

    Thanks so much, Andrea – that is a big, big help PLUS a good resource for future referencing.
    Leon (site moderator)

  • Lyn Harper, RRT moderator
    1 month ago

    That’s actually very funny, rjmoon. You sound like me. I’ve been there, done that. I found it really helped to control the dust in my house. I tend to use it primarily in the bedroom where I feel it’s needed most. I also have a dog, so it made a difference there as well. I hope you find you like for a good price.
    Lyn (site moderator)

  • Leon Lebowitz, RRT moderator
    1 month ago

    Hi again, rjmoon, and thanks for this post. We are good listeners here at, as well as being a good sounding board (kinda the same thing, right?). I was happy your provided your thoughts here and I agree with you. Why not give it a try? From what I can tell, many people on our website are using them successfully.
    Please do check back and let us know how you’re doing. All the best, Leon (site moderator)

  • Shellzoo
    1 month ago

    I do have a humidifier for the Winter but I make sure it is clean. It gets so dry here in the Winter that I would be miserable without it. I don’t have an air purifier because I can’t figure out which one I like. I have read review after review and remain undecided. With my many allergies and asthma I am sure it would be helpful.

  • Andrea M Jensen, CHES (R), AE-C author
    4 weeks ago

    Hi Shellzoo,

    This Guide to Air Cleaners in the Home may help

    These have been certified as “Allergy & Asthma Friendly”

    Good luck!


  • Leon Lebowitz, RRT moderator
    1 month ago

    Hi Shellzoo and thanks for joining in the conversation here in response to Andrea’s timely article. It can be difficult to decide which device to choose. Do you think asking your physician might be helpful? Or, what about discussing this with your colleagues at work – I know you’re a nurse – perhaps some of the pulmonary people and/or respiratory therapists and/or allergists can provide you with some personal guidance.
    Leon (site moderator)

  • Poll