Humidifier Cleaning 101

December 16, 2020 5:11 PM

I recently purchased a humidifier for the first time. I know that humidifiers have to be cleaned very regularly to avoid mold/bacteria problems, but the instructions for my machine say I should be completely emptying everything out and letting it air dry every day. How necessary is this?

So, I recently started waking up with a very sore throat and dry mouth (not to mention the dry skin, chapped lips, and various other winter curses) and decided it was time to try a humidifier in my bedroom at night. To start, I got a cheaper cool mist evaporative machine with a wick filter in part because it seemed easier to clean. I did some reading and was planning on cleaning it thoroughly every Sunday and replacing the filter regularly. However, when I was looking over the instructions that came with my machine, it tells me that I need to empty it out and remove the filter every morning. I live in a smaller apartment and don't have a lot of room to set out the parts of the machine to dry every day. But, I also can see how having the filter just sitting in water could quickly lead to mold growth. For those of you who use (and apparently love!) humidifiers, is this part of your routine? Or can I get away with doing a thorough cleaning once or twice a week? Any other humidifier cleaning tips or tricks that will help?

posted by verity kindle to Home & Garden (10 answers total)

The Wirecutter article about humidifiers mentions that "once a week" is the norm. I should probably clean mine that often, but really, life. (I have their recommendation, which is absolutely great.)
posted by General Malaise at 5:21 PM on December 16, 2020 [2 favorites]

I have two large humidifiers that have what I think is a similar setup and I just use this water treatment in it and change the filter when it gets grotty.
posted by jessamyn at 5:53 PM on December 16, 2020 [2 favorites]

Once a week sounds about right. For us, that includes spraying a bleach spray into the basin and on the parts that stay moist. In our case, you can see the mold/mildew accumulate on the parts if you let them go too long.
posted by mollweide at 5:55 PM on December 16, 2020

When I had one I cleaned it once a week and that seemed to be just right. If I got lazy and waited too long in between cleanings I could definitely tell when I went to clean the parts. You definitely don't want to be breathing in that stuff! (I actually got rid of mine because it was over humidifying and it was a less expensive version that didn't have a built-in humidity reader or any way to set it for just a certain period of time and I also just got tired of cleaning it all the time).
posted by Aranquis at 6:26 PM on December 16, 2020

Wirecutter published an article today specifically on cleaning humidifiers. Short version: you should clean them weekly because there's a small but real risk of serious harm from not cleaning them. "Humidifiers can harbor microbes and blow them or their excretions into your air, triggering an immunoresponse. In acute (sudden, severe) cases, humidifier lung can present symptoms akin to an asthmatic or allergic attack, as Wirecutter’s Tim Barribeau and his now-wife discovered: 'I woke up feeling like we were dying.'"

Also: virtually no one actually does that. "...adults are also vulnerable to ignoring the health risks of dirty humidifiers even when they’re fully aware of them. I can attest to this: I long-term tested our upgrade humidifier pick for about four months in winter 2017–18, and I can recall cleaning it exactly once. I knew full well that weekly cleaning was recommended—I’m the goldang author of our humidifier guides!"
posted by Mr.Know-it-some at 7:01 PM on December 16, 2020 [1 favorite]

This is why I use a steam humidifier. Had the whole mold-in-the-air what-is-making-me-so-sick why-is-this-cold-lasting-forever thing, realized that I could never really trust that vaporizing stuff without steam would be really clean, and also realized that it's probably just safer for me to decalcify my humidifier occasionally and/or use distilled water to avoid mineral buildup. Also, warm mist is lovely in the winter.
posted by amtho at 10:43 PM on December 16, 2020 [3 favorites]

100% agreed with amtho! The other benefit to a warm mist humidifier is it can make your room notably warming, depending on size and ceiling height, which I also consider a strong winter-time benefit. I don't understand why anyone gets the cool version, frankly.
posted by Violet Blue at 1:05 AM on December 17, 2020

I have had good results using wick based humidifier and putting buying silver-based anti-microbial water treatment dinguses in the tank - and changing them every three months or so. I also use the anti-microbial wicks and throw out the plain paper ones.

I intend to clean them weekly - I fail. I do once per month at best with a 10% bleach solution soak in the sink then a full air dry.
posted by sol at 8:02 AM on December 17, 2020 [1 favorite]

FWIW, we once used a cool mist humidifier and found that it left a fine mineral film on every horizontal surface nearby. We switched to one of these things and have been pretty happy ever since.
posted by Thorzdad at 8:59 AM on December 17, 2020

Response by poster: Thanks everyone! This is all really helpful. It sounds like roughly once a week is about the right cleaning schedule to aim for, and I'm relieved to hear I don't have to disassemble it every morning too. Though those warm mist humidifiers are pretty tempting, so perhaps my apartment needs a second humidifier ;)
posted by verity kindle at 2:50 PM on December 17, 2020