Why is my humidifier leaving white dust everywhere?

Using a humidifier to increase the relative humidity in your home is great for your health and comfort when you live in a dry climate or just have very dry winters. But sometimes they can leave white dust on everything. Which give?

When it comes to home care, the last thing anyone wants is more work, so we completely understand your frustration at finding that your humidifier seems to be leaving chalky white dust all over everything. Here's what you need to know about how humidifiers work and how to keep white dust from covering your things.

How humidifiers work

Before digging into the solution to the white dust problem, it's important to first understand how the different styles of humidifiers work.

Evaporative humidifiers: If you have a whole house humidifier attached to your forced air furnace, you are already familiar with evaporative humidifiers. They work exactly as their name suggests. The air is passed over a "wicking" pad soaked in water. This moisture, in turn, evaporates from this pad and is carried into the air by a fan inside the unit (or, in the case of your whole-house humidifier, by the blower fan in your furnace).

Stand-alone evaporative humidifiers work by the same mechanism, they simply aren't hooked up to your home's water supply and you have to fill them manually. An absorbent pad sits in the water and a fan blows air over it to help move it around your living space.

Vornado's Evap40 is an example of a popular stand-alone evaporative humidifier. (However, if you want something a little less institutional and a little more stylish, you might want to pick up their EV200 model.)

Steam humidifiers: A steam humidifier boils water to release a warm mist in the form of steam into the room. While there are advanced whole-house humidifiers that use steam, this is rare. Steam humidifiers are more common in freestanding units.

Most of us are familiar with steam humidifiers, even if we don't realize it, due to the ubiquitous little Vicks brand steam humidifiers that have been on the market for ages - many children have been soothed to sleep during a bad cold or bought bronchitis thanks to these small steam humidifiers. There are also larger versions, such as the Vornado Element A.

Ultrasonic humidifiers: Relatively new to the market, compared to evaporative and steam humidifiers, ultrasonic humidifiers increase room humidity using a different mechanism. Rather than carrying water through the air through evaporation or creating steam to let it drift away, ultrasonic humidifiers eject water from the machine.

A small plate inside the machine vibrates at extremely high ultrasonic frequency with such energy that it shoots tiny water droplets straight out of the humidifier and into the air. The Pure Enrichment MistAire is a best-selling example of this particular design.

The distinct plume of "mist" coming out of an ultrasonic humidifier has a certain charm (and is practically an Instagram houseplant photography staple at this point). However, using an ultrasonic humidifier is not without some problems and pitfalls, so read on as we dig deeper into the whole white dust problem.

Why Ultrasonic Humidifiers Leave White Dust

Now that we've taken a look at how each of the main types of humidifiers work, the question remains, Why do only ultrasonic dehumidifiers leave an extremely fine layer of white dust everywhere?

It all comes back to that high-energy delivery method we just talked about. When water naturally evaporates into the air, only water enters the air. All things in the water stay behind. This is why when you sweat a lot and then dry yourself off in the breeze, your skin can feel grainy – the water is gone but the salt from your sweat remains. Same thing with steam-based humidification. If you boil a pot of water long enough, all the water will eventually go away as steam, but the rust, calcium, and other junk from your tap water will remain caked on the bottom of the pot.

However, ultrasonic humidifiers do not convert water to steam. They just shoot the water through the air almost like it's being shot around the room from microscopic squirt guns. This means that all water impurities travel with the water into the room.

That white dust on everything? These are the minerals in the water you put in the ultrasonic humidifier. When you wipe your finger on your dresser and the dust looks white and more chalky than usual, that's because it is. Instead of regular household dust, it's regular household dust plus an incredibly thin layer of calcium and other mineral "chalk". If you purchased an ultrasonic humidifier for your houseplants, you'll likely find dust on their leaves as well.

In addition to finding dust deposited on flat surfaces like the top of your dresser or coffee table, you'll likely also notice that dust coats vertical surfaces very well and is particularly attracted to electronics. Because it's a superfine powder suspended in moist air, it's more likely to stick to vertical surfaces and it's very attracted to anything with a static surface charge like the body of your TV. or your computer screen.

Is white dust harmful?

If you found this article while searching for answers about mysterious dust in your home, you may have simply been motivated by boredom of dealing with dust. But you might also have been curious about whether it's harmful.

While you shouldn't panic about dust, you should also do all you can to avoid it. Why? Because if you wipe a lot of fine white dust on everything, you're also breathing in the same air saturated with white "rock dust" minerals from your tap water (along with all the other tap water impurities that the ultrasonic humidifier is ejected into the air with the minerals).

Nothing good ever comes from breathing in ultra-fine particles, and research on mice indicates that particles from ultrasonic humidifiers penetrate deep into lung tissue. Another study found that using a small ultrasonic humidifier in an upstairs bedroom increased the level of fine particulate matter in whole-house air when air was circulated through the forced-air heating system. .

It's certainly not as dangerous as grinding concrete without protective gear or working in an asbestos mine, of course, but if you can avoid putting unnecessary particles in the air, you'll be better off. .

How to Avoid White Dust

Whether you want to avoid extra dusting work or are worried about inhaling a mist of ultra-fine particles, there are two simple solutions.

First of all, if you already have an ultrasonic humidifier or just prefer to use one (the plume of mist that comes out of it is pretty neat after all), you can continue to dust-free and safely by going through to distilled. the water.

Steam distilled water is inexpensive and available in abundance at almost any grocery store. The water is free of impurities and when used in the ultrasonic humidifier, it won't leave white dust (or anything else) on your furniture or electronics. If you're tired of buying small jugs, by the way, you can often find distilled water in 5-gallon jugs at water utilities.

Second, if you don't want to go through the expense and hassle of buying carafe after carafe of distilled water, you can skip this whole process by buying evaporative or steam humidifiers like the Vornado EV200 or the Vornado Element A. The only downside here is that you will need to clean the machine every now and then with a mild acid like white vinegar to remove the minerals left behind during the evaporation process.

If you're dealing with very dry winter air, you might want to stick with evaporative humidification. Even though distilled water is cheap when you just buy a gallon here or there for your iron, it quickly builds up when you try to increase the humidity in your home. It's easy to put a gallon or more of water into the air per day in dry climates. If you use tap water, you can add up to $30 to your water bill per month. If you use distilled water, you will easily spend over $XNUMX per month for the same increase in humidity.

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Whether you remove the minerals from the start (using distilled water) or use a method that keeps the minerals in the machine (evaporation or steam), you will avoid white dust. Even better, you'll enjoy a more comfortable living space with less dust!