Do Air Purifiers Collect Dust? Absolutely, and Here’s Why


When it comes to cleaning the air inside your home, dust can widely range in size. It could either be considered a fine particle, but can also be as large as 20 micrometers across and more.

So to collect a pollutant such as dust, you’ll need filters that can trap both small and large pollutants.

But can an air purifier really collect dust? As long as your air purifier has a HEPA filter, it should be able to trap most of the dust that’s present in the air. However, this doesn’t mean that an air purifier alone can solve a dust problem inside a home. It still takes regular cleaning to remove the dust that deposits on surfaces as well.

To clear up some of the confusion about air purifiers, and help you understand what it takes to find the one that’s right for you and your home, let’s go into more detail.

What Is Inside Dust?

Dust is a mysterious kind of pollutant. While most other pollutants can be pinpointed in terms of their size and specifics, dust cannot.

You see, dust can be many different things like:

  • dead skin cells
  • textile fibers or any other fibers
  • soil tracked in from the outside
  • animal dander and waste
  • insect waste
  • dryer lint
  • mold spores
  • food debris
  • soot from the outside or through burning wood inside
  • pollen
  • smaller, more dangerous pollutants like bacteria, viruses, tobacco smoke, lead, and even arsenic

The list above doesn’t even scratch the surface of all that could be found inside dust. It’s just impossible to tell what exactly will get caught up in it.

It isn’t to say that pollen alone is dust, that mold spores alone are dust, or that soil alone is dust. Obviously, these are a separate category of pollutants.


Why the Size of the Dust Matters

Dust is a collection of pollutants that clump up together, which explains why dust overall can be a regarded as a small particle and a large particle at the same time.

Most dust will fall in the range between 1 to 20 micrometers in size, although it isn’t unusual for some of it to be 100 micrometers and larger. Anything above 40 to 50 micrometers or so is visible to the naked eye. A single hair is about 100 micrometers in diameter, for comparison. Some dust could also be categorized as a fine particle.

Fine particles, or particulate matter 2.5, are regarded as pollutants less than 2.5 micrometers in size and are especially important to those with allergies and respiratory problems. That’s because pollutants that are this small in size are harder to filter out by the body and can get lodged in the mucous membranes of the nose, windpipe, or lungs.

Large dust particles can also pose a problem. The more dust that there is, the more nutrition there is for dust mites to feed on. Dust mites are quite large (hundreds of micrometers in size) and can cause something known as dust mite allergies because they are known to produce allergens that can flare up asthma and other conditions.

As you can see, dust is not good for our home or health, no matter what its size is.

Can an Air Purifier Really Remove Dust?

The short answer is – yes.

As long as you can get a filter that can remove the dust that’s on the smaller range of particle size, most of the dust in theory should be removed.

So, a good air purifier should be able to trap particles that are 1 micrometer in size. The best mechanical filter that can do that is the True HEPA filter, which is said to remove 99.97% of airborne particles 0.3 micrometers in size and above. Every True HEPA filter has to be verified by third party laboratory testing before its manufacturer can make this claim.


The Limitations of an Air Purifier

Read any product review by any allergy sufferer and you’ll quickly realize that more people have been helped by purchasing an air purifier than not.

Research supports this, too. In this Asian research study, the introduction of HEPA filters inside the homes of hay fever sufferers decreased the number of dust mites and bedding allergens, as well as particulate matter of 1, 2.5, and 10 micrometers in size.

But as with anything else on the market, nothing is perfect and neither is an air purifier, no matter how good the reviews or research are.

So to set realistic expectations, here are a few things that you need to know as a consumer:


Air Purifiers Undergo Laboratory Testing Conditions

Laboratory testing has strict conditions that may not represent real life.

A laboratory test doesn’t take into account that you may open the patio door and reintroduce pollution to your home or that you may have high ceilings or obstructive furniture that limits the air flow of the air purifier. All laboratory tests are also performed on brand new filters and don’t take into account that a filter may not be as effective as it accumulates more pollutants through its everyday use.

It may be tempting to buy a HEPA-like filter instead of a True HEPA filter or to buy a less powerful air purifier in order to save money. But given this information, it doesn’t make sense to buy anything less than a True HEPA filter if you want real results.

(You can learn more about the differences between True HEPA and HEPA-like filters, as well as air flow in this guide.)

Air Purifiers Are Only for Airborne Particles

Wouldn’t it be nice if an air purifier could eliminate the need to dust your furniture and vacuum your floors?

Air purifiers can only eliminate airborne particles. Their purpose isn’t to suck up dust from surfaces or to get them out from the carpet fibers. So even when a True HEPA does eliminate the 99.97% of airborne pollutants, know that there will still be a lot of dust left in anything that’s not airborne in your home.


Air Purifiers Collect Pollutants, But They Don’t Kill or Remove Them

There’s a reason why air filters need to be changed out and why some of them must be washed. And no, it’s not just because they get clogged up.

You see, the mechanical filters inside air purifiers never fully eliminate the problem of pollutants.

Even though those pollutants stay trapped in the filter, many of them can still release endotoxins back into the air. Endotoxins are molecules that are usually released from bacteria, causing allergic reactions. These bacteria tend to coexist simultaneously with some of the larger pollutants in the air like dust and mold, for example.

This research study by Michigan scientists is a great overview of this topic, explaining how the endotoxins found in dust contribute to childhood asthma and wheezing in babies, among other things.

Therefore, if you find that an air purifier isn’t alleviating your or your child’s flare-ups, it may not be that the HEPA filter doesn’t work. Rather, it could be that the bacteria and the endotoxins that they’re releasing are small enough to bypass the filter.

Many air purifiers have another filter besides the HEPA filter to take care of these smaller pollutants. An activated carbon filter can definitely help in this case, especially if you get a heavy filter with actual granules inside. Stay away from ozone-generators. There are safer ways to kill bacteria (I use the Winix with its PlasmaWave technology in my own home).


Other Consideration For Your “Dust Removal Plan”

There’s no doubt about it, an air purifier can help with airborne dust.

But to alleviate any discomfort caused by asthma or allergies, you’ll need to decide what to do with the surface dust in your home as well. So to finish off this post, I’d like to share some simple ideas that you can implement today to help you achieve this.

Here they are –


Replace Your HVAC Filters

Most HVAC filters are inexpensive filters, but did you know that those are only rated to protect the furnace (if they are rated at all)? In other words, they have a bigger purpose of making sure a small stone doesn’t get into the ducts than to make sure you can breathe fresh air.

So, replace those filters with better quality filters.

I know that electrostatic filters are often used to fight dust. They also don’t need to be replaced since they’re washable, so it’s definitely a plus.  The problem I have with them is that they typically only tackle larger particles and that they need to be cleaned constantly to maintain their advertised efficiency of collecting dust.

I prefer the MERV-11 rated pleated filters instead.

They’re just enough of an upgrade to improve the air, but aren’t too thick to compromise the air flow of the unit in my home. I get my filters from Amazon every 2 months and never have to worry about when to change them out.

Again, it might be wise to try one or two filters in your own home to assess how well your unit handles it and whether it restricts the air flow. In my home personally the air flow was just fine with these MERV-11 filters, but combined with my two air purifiers, I could sometimes swear it feels like I’m sitting outside on my backyard swing bench every day.

Control Humidity Levels

Dust is typically associated with dry air, so it makes sense to introduce a humidifier into a home.

Which may make sense if you live in the Nevada desert or some other dry climate like that.

For most other homes, however, you’d be surprised to find out that the problem is too much humidity. This is especially true in the summer.

Dust mites not only survive on the organic matter found inside dust, they also love moist environments. In fact, they are known to be able to survive all year in homes with high humidity, according to the Asthma and Allergy Foundation of America. If your home has 70% to 80% humidity levels, it’s the perfect environment for dust mite growth.

Not only are dust mites a problem at high humidity levels, but air purifiers also become less effective at trapping dust when there is too much humidity. Here’s a guide on dehumidifiers in case you’d like to look into this. You want to get your home’s humidity levels down to between 35% to 50% ideally.


Reduce Static In Your Home

Find ways to reduce static in your home. This is probably the biggest attractant of dust. Use fabric softener and softening dryer sheets. You could even clean the surfaces that are prone to static in your home with those dryer sheets.


Clean Dusty Surfaces with a Damp Cloth

Rather than just forcing the dust up into the air when dusting with a standard hand duster, clean your dusty surfaces with a damp cloth. You want to actually remove the dust, not just transfer them from a surface into the air.


Change Out Bedding More Frequently and Regularly Clean Soft Furnishings

One of the major sources of dust in a home is bedding, along with soft furnishings like sofas, chairs, and curtains.

Make it a habit to change out your bedding more frequently. Weekly is ideal. Again, use plenty of dryer softening sheets when washing your bedding. There are also organic pillows and bedding that are made to be dust-mite resistant.

While some designer quality curtains are dry clean only, you can still vacuum the fabrics every once in a while to get the dust out. When vacuuming the floor, make it the habit to pull out the brush attachment every week and to get the dust out of your sofas and chairs as well. Cleaning with a damp cloth with mild detergent and water can help, too.

Stop Dust At the Door

60% of the dust in our homes comes from the outside. Most of that is brought in with our shoes.

So, find ways to better trap all the dirt on the soles of your shoes. Buy extra mats and place them throughout. Make occupants take their shoes off outside, then neatly store them away.

Manage your pets, too, and don’t allow them to constantly go in and out of the house without at least wiping their paws once in a while.


Replace Carpet Flooring with Harder Flooring Materials

Dust tends to accumulate in between carpet fibers. No matter how often you vacuum, it will still be impossible to get it all out.

It might be a good idea to change out the carpet floors for surfaces that won’t allow dust to accumulate so easily. And if it’s not something that you can afford at the moment, you can always invest in a vacuum cleaner with a good HEPA filter.

Be careful about claims that vacuum manufacturers make that their HEPA filters can trap a certain percentage of things like dust mites.

First, the dust mites themselves aren’t what’s causing the allergic reactions. It’s the endotoxins that they release. So yes, the vacuum cleaner may in fact trap 100% of the dust mites, but what about their fecal material and endotoxins?

Second, look for True HEPA instead of HEPA-like, HEPA-style, or any other creative way to circumvent stating that a filter only uses HEPA media but wasn’t tested against HEPA standards.

Again, the idea isn’t to get rid of bacteria, viruses, or the very small pollutants (that’s not what a HEPA filter is intended to do anyway). It’s to make sure the filter is able to trap the majority of the dust particles that are around the 1 micrometer range.