Ultrasonic Humidifiers with Tap Water : an interesting warning

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My wife bought some of these units last winter, and they left white residue all around them - it was the minerals in the water. Stopped using them...
 
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Unless distilled water is used, it's inevitable that solids will precipitate when the ultrasound-generated water droplets evaporate. Other types of humidifier, that generate water vapor instead of droplets, will generally be better in this regard. Of course, that leads to scaling of the heating element, but I haven't found that to be a problem in practice, they still function adequately for many years.
 
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Unless distilled water is used, it's inevitable that solids will precipitate when the ultrasound-generated water droplets evaporate. Other types of humidifier, that generate water vapor instead of droplets, will generally be better in this regard. Of course, that leads to scaling of the heating element, but I haven't found that to be a problem in practice, they still function adequately for many years.

We have a humidifier unit on our main HVAC system, and as you say the mesh gets scaly (we clean it every year to remove that) but we just have city water going to that and there's no issue. I was surprised when we started seeing all this white particulate all over the place when we used these small units...
 
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I was scared there for a minute, but from the article (italics mine):

“It is important to note that PM generation happens with ultrasonic humidifiers but you can use tap water with evaporative, wick-based humidifiers which does not break up the water molecules in the same way.”

Literally everyone I know who uses a humidifier, either for their bodies, furniture, or guitars, use the evaporative wicking filter type. Maybe we’re all just low-tech.

Please set me straight if I misread or misunderstood the article.
 
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Please set me straight if I misread or misunderstood the article

You read correctly, but presumably many ultrasonic humidifiers have been sold, and are in use. [Which a quick glance at the Amazon numbers would seem to confirm.]
 
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We have a humidifier unit on our main HVAC system, and as you say the mesh gets scaly (we clean it every year to remove that) but we just have city water going to that and there's no issue. I was surprised when we started seeing all this white particulate all over the place when we used these small units...
It's the difference between evaporative and ultrasonic methods. The ultrasound causes cavitation and literally spews droplets of the water into the air, so the composition of the droplets is basically the same as the bulk water. The unit on your HVAC (we have one also) evaporates the water from a high surface area material (with or without heat, depending on the unit), so it has very little dissolved solid, and the permeate is slightly more concentrated.

As you probably know, some small portable units also use evaporation.
 
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You read correctly, but presumably many ultrasonic humidifiers have been sold, and are in use. [Which a quick glance at the Amazon numbers would seem to confirm.]
Absolutely, many people do use the ultrasonic style.
 
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I recall decades ago having used rolled up newspapers in a big bowl of tap water...

Cheap, effective and beautiful! 😁
 
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Breathe those particles or swallow them, either way your dead in the end.
 
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Breathe those particles or swallow them, either way your dead in the end.
Maybe you were making a joke, and it's true that we're all dead in the end, but in this thread we are mainly talking about non-toxic soluble salts/minerals in tap water that can cause health problems when inhaled in particulate form.
 
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My furnace started short-cycling a couple years ago. I replaced the filter as the first, easy troubleshooting step. That fixed it, but the issue came back after a couple weeks. Called a technician, who blamed it on using a very restrictive (MPR 2200) filter. It made no sense to me, but his diagnosis was at least related to the main issue. I compared a 2-week old filter to a new one, and realized how much more white it looked. The culprit was what you shared above.

I don’t have a reason to use a humidifier all the time anymore, but when I do, I fill it with the water from my reverse osmosis tank and don’t have to deal with the white dust that goes all over.
 
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My furnace started short-cycling a couple years ago. I replaced the filter as the first, easy troubleshooting step. That fixed it, but the issue came back after a couple weeks. Called a technician, who blamed it on using a very restrictive (MPR 2200) filter. It made no sense to me, but his diagnosis was at least related to the main issue. I compared a 2-week old filter to a new one, and realized how much more white it looked. The culprit was what you shared above.

I don’t have a reason to use a humidifier all the time anymore, but when I do, I fill it with the water from my reverse osmosis tank and don’t have to deal with the white dust that goes all over.
Apparently you have forced air heating, so you might look into a whole house humidifier. Depending on your house and climate, a bypass humidifier may be sufficient, and they're not terribly expensive. I waited until I replaced my furnace to install one, but in retrospect there was really no reason to wait.
 
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Thanks, Dan. I already have a bypass humidifier on my furnace, but for a while, it was not enough for my wife. Luckily she changed her mind at some point.
 
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Thanks for the PSA. I had to check since we started turning on our humidifiers. All of ours were evaporative so I guess we're good?

Better break out the air quality monitor just to make sure.