How to Prevent White Dust from Humidifier

Humidifiers are a great way to relieve dry skin, but they can also create something called white dust. 

This is because humidifiers release water droplets into the air that contain minerals from the water. 

The minerals then evaporate, leaving behind a small white residue on furniture and floors. 

To prevent this problem, use distilled water in your humidifier because it has lower mineral content than tap or bottled waters do.

What is White Dust?

White dust is what happens when your humidifier calls for water. It’s the minerals in the water that are left over after evaporation. Those minerals can be pretty harsh on surfaces, so it’s important to clean up white dust as soon as possible.

What Causes White Dust in Humidifier?

There are several reasons why humidifiers produce white dust. The most common reason is water droplets evaporating from the moistened surfaces of the unit and leaving mineral deposits on surrounding furniture, walls, or ceilings. 

Another cause can be a dirty humidifier filter which will also release dust into the air.

If you have a humidifier in your home, it’s important to keep it clean to prevent the spread of dust and other allergens.

Is Humidifier White Dust Harmful?

Humidifier white dust is not harmful, but it can be annoying. Fortunately, it’s easy to clean off like any other dust in your home. No special care is required. 

The density of your water will determine how thick or thin this layer of white dust is (hard water has higher mineral content. Therefore, the harder your water, the more dust you’ll find).

What to Do about White Dust from Humidifier

While white dust may be an eyesore, it is not a major irritation to remove. You can usually use the same cleaning procedures and products for regular dusting in your house.

If you want to alleviate the white dust for good, there are a few options to consider. They include:

Use distilled water to fill your humidifier instead of tap water – This will ensure that fewer minerals can get on the ground.

Install a water softener system – If mineral-rich water ends up in your humidifier due to hard water, a water softener system can fix the problem and help your plumbing and appliances, such as the washer and dishwasher.

Consider installing a demineralization cartridge in your humidifier to catch minerals before the water is vaporized and distributed around your house.

You can also consider switching to a warm or cool mist humidifier system that functions differently than other types of humidifiers.

How to Prevent White Dust from Humidifier

If you see a lot of white specks on your furniture, it might be white dust. These are minerals from the water in your humidifier – calcium and magnesium. The minerals come out when the water is turned into mist in the air.

Ultrasonic and impeller humidifiers do not release these minerals. If you have allergies, asthma, or other lung and sinus issues, white dust from your humidifier is unusual. You may avoid white dust when using your humidifier by having a simple maintenance schedule.

Empty the Reservoir Once a Day after You’re Done Using the Humidifier

Don’t leave water in the reservoir for more than 24 hours. Remove the top reservoir from the base and unscrew the cap at the bottom. Pour out all of the water from the reservoir and into your sink. Fill it up with distilled water when you’re ready to use it again.

Water that sits in the reservoir for too long can make mineral deposits on the sides of the reservoir. That could cause white dust.

If you use your humidifier all day, be sure to change the water every day.

If there are 2 reservoirs in your humidifier, you will need to empty both of them every day.

If you have houseplants or a garden, you may water them with the old water from the tank without harm.

Fill the Tank with Distilled Water Only

Only distilled water should be used when refilling your humidifier’s reservoir. You may get it by the gallon at most grocery, convenience, or drug stores.

Distilled water is made by taking out the minerals from the water. The minerals make white dust on things.

Maintain the Humidity Level in Your Home Between 40 and 50 Percent

Get a humidity meter for your house if your thermostat doesn’t already include a humidity function. Check it at least once a week to ensure that it remains between 40% and 50%.

If it’s too high, take the humidifier off for a few weeks to allow the moisture level to decrease and test it again to ensure that it remains within the acceptable range.

Excess moisture in the air can contribute to dust, mold, or mildew growth in your house and within the humidifier, increasing the chance of emitting white dust (along with mold and mildew—not something you want in your home).

Soak a Demineralization Cartridge and Drop it Inside the Reservoir

Fill a bowl with 8 fluid ounces (240 mL) of water and submerge the tiny cartridge for 10 minutes. After draining the water, fill your humidifier’s reservoir with distilled water.

The cartridge will stop calcium and lime from building up in the tank.

Some ultrasonic humidifiers come with some demineralization cartridges. If not, you can buy them at a store that sells humidifiers.

Change the Filter at Least Every 1 or 2 Months

Check the instruction manual to find out where the filter is and how to replace it. In most situations, it’s attached to a cylindrical chamber that sticks up from the bottom of the device.

Remove the reservoir and twist open the top latch or cap on the cylinder to change it. Slide the old filter out and replace it with a new one.

If you use your humidifier daily, change it once a month. You may wait 2 months before changing your humidifier if you only utilize it a few times each week.

Refer to the manufacturer’s instructions that came with your device for information on when to change the filter.

Some humidifiers include replacement filters, but you may purchase them from a home goods shop or online if yours does not.

How To Clean Humidifier – Step-by-Step 

When it comes to cleaning a humidifier, there are various crucial steps you need to take to ensure you do it right. Check out these steps below.

Turn Off the Humidifier and Unplug It

Humidifiers tend to have an electric shock depending on the model if you aren’t careful. Always turn it off, unplug it before opening it up, and be wary of electrical equipment. 

If you have a warm steam or vapor humidifier that has been on for a few hours, turn it off and wait at least 30 minutes before handling it to allow it to cool down.

During winter, try not to use a warm vapor or steam humidifier for at least an hour after it has been turned on. The hot steam might burn your skin if you attempt to open or clean the device right away.

On the other hand, Warm mist humidifiers do not produce white dust, and they should be cleaned regularly.

Scrub the Inner Side of the Reservoir with Soap and Water

Empty the water from the reservoir. Put in about half of the reservoir with cold tap water. Add soap to make it sudsy.

Use a sponge to scrub the sides of the water reservoir. Pay attention to any spots with white lines or splotches – those are mineral deposits.

Harsh chemicals or disinfectants like bleach may cause lung problems if they’re not washed away and get into the air. So, use mild dish soap instead, which is better.

Remove the Filter if Your Humidifier Has One

Take the filter out of the humidifier’s reservoir to open it. If you don’t know where your filter is, consult your humidifier’s owner’s manual or search for the model for your particular device online.

Filters are required for cold evaporation, warm evaporation, and hot steam humidifiers, whereas ultrasonic humidifiers do not require them.

Rinse the Filter Under Running Water

Clean the filter by putting it under running water. Massage the filter with your fingers while you rinse it. 

Shake off the water when you’re done. Then let it dry on a paper towel for 1-2 hours.

You can scrub it with a brush if there is a lot of dirt.

Don’t put the filter back into the motor casing until it is fully dry. Wetness can make mold and mildew growth.

If there is mold or build-up on the filter, fill it with water and vinegar for 20 minutes. 

After 20 minutes, drain the solution from the filter and rinse it very well under running water until you can’t smell any of the vinegar.

Soak the Reservoir’s Base with Vinegar and Hot Water as an Alternative

Empty the water from the reservoir, and then put 2 tablespoons of white vinegar and 17 fluid ounces of water into it. 

Put this same thing into the base. Let it sit for 20 minutes, and then rinse both parts until there is no more vinegar smell left.

When you’re done cleaning, fill the reservoir with distilled water. Plug it in and enjoy your steamy, clean air.

Mix vinegar and water together. This will help clean the mineral deposits on the inside of the reservoir.

If you hurry to clean your reservoir, shake it and then rinse. But if you have the time, leave the solution in for 20 minutes before shaking and rinsing.

Pro Tip: It is best to clean your humidifier once a week. If it starts making white dust, you might need to clean it more often or change the filter.

Humidifier Maintenance Tips

Humidification systems that are properly designed, specified, installed, and maintained operate flawlessly for years. 

When problems with the humidifier occur, look at the troubleshooting guide. 

However, keep in mind that other HVAC issues, such as temperature or airflow control, might also be responsible. 

Consider the following humidity maintenance instructions.

Always follow the Manufacturer’s Recommended Maintenance Schedule.

The greatest defense against field concerns is constant inspection and maintenance.

Maintenance standards differ depending on the type of humidifier (cleanable boiling chambers vs. disposable) and water quality (hard, naturally soft, demineralized, or softened).

All systems should be inspected after the first three months of use to see what needs to be done in the future.

Check Whether the Operating and Design Parameters Match

Running a humidification system within the limits for which it was designed will also ensure that systems operate effectively.

For example, if a system is intended to operate in a humidified area with a 35 percent relative humidity (RH) requirement. 

But building users are operating systems at 55 percent, available absorption distance in ducts can become insufficient, resulting in duct dampness.

You want to make sure that you tell people what you expect from them in the building.

Power and Controls Maintenance

It is good to start with something you know how to do. For example, you can fix electrical connections such as fuses, sensors, and contractors.

A signal going to a humidifier from a transmitter, humidistat, or building-automation system must be compatible with a signal the humidifier is set to receive. 

For example, if the controller is not wired or programmed for 4- to 20-mA signals, it will not understand them.

Signal input is generally adjustable by a controller board or the controller’s software. 

Specific instructions will be included in the control manual. All control components should be connected according to an appropriate wiring diagram.

Maintenance of Dispersion Assembly

If the installation is done properly, steam dispersion assemblies run smoothly.

They operate on the same principle as an automatic toilet: they spray distilled water around to prevent clogs, no moving parts and are mostly welded metal with a few exceptions.

If water is not treated, adiabatic (unheated) humidifiers can block. The disks in ultrasonic humidifiers require replacement regularly.


Preventing white dust from humidifiers is simple and important. By following the tips we’ve outlined in this post, you can keep your humidifier running smoothly without producing any annoying white dust.

If you happen to have any questions or feedback regarding this post, you can post them in the comments section below. Alternatively, feel free to reach out to us through email, and we’ll be happy to help!