High quality air purifiers can remove up to 99.97% of the contaminants in the air we breathe. However, if you have noticed some white stuff in and around your air purifier, you might be concerned that your air is not safe to breathe.
Electrostatic air purifiers can produce white dust as a by-product of air filtration. The dust accumulates because the purifier is saturated and needs cleaning. Other air purifiers (e.g., Ionizer, HEPA, activated carbon) can accumulate white powder from operating in the same room as a humidifier that uses tap water (or hard water).
It’s important to know not only which type of air purifier produces white powder, but whether it is normal, and what you should do about it. Read the article to learn all this and more!
Do All Air Purifiers Produce White Dust?
All air purifiers draw in air, pass it through a series of filters, and then dispense the purified air back into the room. However, there is a large variety of air purifiers, which mainly stems from the type of filtration, and not all of them produce or accumulate white dust.
To understand which air purifiers can produce or accumulate a white dust, it is essential to know the different types and how they work.
Types of Air Purifiers
There are 5 main types of air purifiers:
- Electrostatic: These use static electricity to trap airborne contaminants. It positively charges the particles in the air (as it passes through the system), to removes the contaminants and disperse fresh air.
- HEPA/Activated Carbon: These are regular air purifiers that feature a set of filters, primarily a generic pre-filter, an activated carbon filter, and a True HEPA filter. These consecutive filters allow more than 99% filtration of dust, debris, microscopic pathogens and particles, and gases. Some units may also have only one of the two filters.
- Ionizer: Ionizers are devices that remove particles from the air by using negative ions. The particles settle down on the floor and surfaces. These purifiers can remove pollutants like dust, dander, and pollen.
- Ozone Generators: Ozone generators produce ozone gas to change the molecular composition of particles and sanitize the air.
- Air-to-Air Exchangers: These do not filter the air but improve the room’s air quality by ventilation. They bring clean, fresh air into the room and push stale air out.
Air purifiers that produce white dust
Out of the many types of air purifiers, only the electrostatic units produce white dust. This white dust often accumulates next to the air purifier and may also be found within its duct systems.
Electrostatic air purifiers feature a filtration duct made of two negatively charged magnetic plates with a positively charged metallic mesh. Turning the air purifier on pulls the room’s air in through the inlet and passes it through the filtration duct.
Being small in size, air molecules pass through the magnetic plate, and thus, they do acquire any charge. The large-sized airborne pollutants, on the other hand, come in contact with the metallic gauze and become positively charged.
The magnetic plates, being oppositely charged, attract the dust particles and, this way, remove them from the air (which is emitted into the room).
Over time, the electrostatic air purifiers become saturated and can only filter small particles. As a result, the heavy particles settle within and outside the unit and appear as white dust.
An air purifier usually takes 4-6 weeks to collect significant white dust.
Should You Worry About White Dust?
White dust is a by-product of air purification and does not mean the unit is malfunctioning. Instead, it is normal for electrostatic air purifiers to produce white powder when operating for long periods of time, and so, the dust is a sign that your system is working.
However, the accumulation of a large amount of white powder indicates that you need to clean your air purifier. As the magnetic plates continue to attract airborne particles, they become saturated and eventually are unable to efficiently provide maximum filtration.
Therefore, for the air purifier to continue filtration, you must clean it every few weeks.
How To Clean White Dust
You can easily remove the white dust lying on the floor or around the air purifier by wiping it with a damp cloth (or vacuuming if on carpet). As for the white powder and other pollutants deposited within the system, here’s how to properly clean them:
- Switch of the unit and disconnect it from the power outlet.
- Refer to your user manual and remove the filtration duct (collection array). Most modern systems feature a latch button that you press to pull out the array.
- Spray room temperature water on the array and brush its collector plates to remove dust.
- Let it dry before placing it back in the system.
- For the exterior body of the unit, use a moistened cloth and simply wipe the outer surfaces.
Most manufacturers recommend cleaning electrostatic air purifiers every two weeks.
Although electrostatic air purifiers have a low MERV rating, i.e., < 4, and they remove only less than 20% of dust, their cost-effectiveness and long-life offer a significant advantage over True HEPA and other regular air purifiers.
Unlike other air purifiers, electrostatic units also do not require regular filter replacement. Therefore, for a low pollution area, they make for a good choice.
Why Is White Dust Collected On Regular Air Purifiers?
Although the white powder is a by-product of only electrostatic air purifiers, you might also find some of it deposited on and around other types of appliances. This white dust comes from humidifiers and is a common complaint from people who use an air purifier-humidifier combo device.
Humidifiers are devices that disperse moisture to the air. This humidification is achieved by converting water stored in the tank into vapors.
The white dust comes from mineral deposits that accumulate in the tank due to tap water (or hard water). Hard water contains significant concentrations of minerals like calcium and magnesium, which are left behind in the tank and within the system as the water evaporates to form vapors.
Over time, the mineral build-up forms scale deposits and clogs the unit. When this build-up is extensive, some of these minerals (white dust) are also dispersed out of the system along with purified and humidified air. This explains why white powder is often found on the floor and furniture surrounding air purifiers-humidifier combo units.
This can be avoided by only using distilled water in the reservoir of the air purifier-humidifier combo unit.
How Does White Dust Affect Health?
White dust from air purifier-humidifier combination units is primarily mineral content that usually settles on the floor or surrounding surfaces. Therefore, it is not directly harmful to health.
However, white dust can also disperse in the air when released along with purified air. Inhaling this powder can trigger respiratory allergies. A common respiratory problem called childhood lung injury is often associated with the inhalation of white dust produced from ultrasonic humidifiers.
How Does White Dust Affect Furniture and Walls?
The white powder is released with mist from the unit. As the moisture dries, the white dust settles on the furniture and sticks to the walls. While we know that the white dust doesn’t necessarily mean the unit is malfunctioning, it can damage furniture and wall paint.
Since white dust only comprises dried minerals, there is no great risk of furniture or paint damage through them. However, if not cleaned regularly, the dust may form hardened deposits that you may find difficult to clean. Scrubbing the hard build-up can then damage the paint or fabrics.
How To Prevent White Dust From Air Purifier-Humidifier Combination Units
Air purifier-humidifier combo devices are ideal in dry areas. Obviously, the white dust produced from them is a nuisance, and here’s how you can prevent it:
- Distilled Water: Fill the tank with distilled, demineralized water instead of tap water to reduce mineral deposits.
- Demineralization Cartridges: These are small pieces of equipment installed in the humidifiers to reduce mineral build-up. If distilled water is not available, you can use a demineralization cartridge to remove minerals from the water before it is vaporized.
- Water Softener Systems: This is a filtration system that removes mineral content from the water. It is essential to note that water softener systems are directly installed in the plumbing pipes rather than within the humidification unit.
- Clean the Tank: Cleaning the water tank regularly is another major step in avoiding white deposits. Turn the humidifier off and detach the base to remove the water tank. Empty the tank and fill it with a white vinegar solution (made of water and vinegar in a 1:1 ratio). Let it sit for 30 minutes to an hour, and then rinse. The acetic acid in white vinegar acts as a solvent and efficiently dissolves mineral buildup.
Frequently Asked Questions
The following FAQ offer some helpful insight into white dust and air purifiers:
Do Air Purifiers Cause White Dust?
Only electrostatic air cleaners produce white dust when running for a long time. White powder on other regular air purifying units comes from the mineral deposits in the water tank of humidifiers.
Note that for regular air purifiers to collect white dust, they don’t necessarily have to be in combination with a humidifier. Instead, operating a humidifier and air purifier in the same room can cause white powder accumulation on surrounding surfaces and appliances (including air purifiers)
Why Does My Air Purifier have Dust On It?
Air purifiers might have white dust produced as a by-product of filtration (electrostatic air purifiers) or from humidifiers operating in the same room. Dust and debris from the surrounding air can also deposit on the air purifiers.
