The Best Air Purifier For Dust

Dust is everywhere. Why? Because dust generators – sources for dust - are everywhere.

In most homes, two thirds of dust comes from outdoor sources and one third of dust comes from indoor sources.

Outdoor sources include

• natural sources like soil and pollen and
• man-made sources like pollution (eg. particles in exhaust fumes produced by industry and motor vehicles).

Indoor sources include

• human beings and animals (skin cells, hair),
• textiles and papers (fibers), and
• anything else that produces tiny particles that become airborne and eventually settle (cooking food and dust mites, for example – more on both of these examples later)

The level of dust in your home from outdoor sources depends on

• How close you are (proximity) and
• How much of it is there (concentration)

The level of dust in your home from indoor sources only depends on

• How much of it is there (concentration) - the number of human beings, animals in the home; the number and extent of textiles, fibers in the home – e.g. fabric couches, carpets, etc. How often you cook, what you cook with (concentration, frequency)

Airborne dust

Wikipedia defines dust as “fine particles of solid matter”.  Note that the definition does not put a limit on the size of the particles.

Dust is either airborne or settles on a surface depending on the size of the particles that comprise the dust.

Size of particle vs how long it stays airborne:

Thus, a dust particle that’s 0.5 microns or smaller might stay airborne for several days. A dust particle that’s larger than 100 microns will fall to the ground in a matter of seconds. Of course, the estimates above do not take into account:

The former will increase the time it takes for dust to settle while the latter will constantly “push” more dust into the air.

So, how can we remove these dust particles from the air?

An air purifier equipped with a HEPA filter will take care of any and all airborne dust particles, no matter their size.

Of course, the dust particles have to actually make it to the air purifier’s HEPA filter to be removed from the air. And many don’t.

Many are too large and fall to the ground or are so large that they get filtered out by the air purifier’s pre-filter before they even get to the HEPA filter.

But the smallest particles – the ones that stay airborne the longest – are going to be filtered well enough by the air purifier’s HEPA filter.

HEPA filters have a standard efficiency rating of 99.97% for particles in the 0.3 micron range (0.3 microns is the most difficult size to filter which is why the efficiency is given in these terms). Efficiency actually improves as particles get smaller (below 0.3 microns) or larger (above 0.3 microns). That means that for every 10,000 0.3 micron dust particles that travel through a HEPA filter, only 3 will make it through. For every 10,000 dust particles of other sizes it’s quite possible that none make it through.

The bottom line here is that HEPA filters are extremely efficient in filtering out dust particles. You just want to make sure that you buy an air purifier equipped with a HEPA filter. There are various units on the market that have HEPA type filters or proprietary particle filters that are not HEPA. Only a HEPA filter will give you guaranteed particle filtration to the extent that we described above.

The best HEPA equipped air purifier we’ve tested so far – the one unit we would recommend as the best air purifier for dust - is the Winix 5500-2. This unit provides the perfect combination of energy efficiency, noise output, and value.

Special note on cooking

Cooking releases

The source of this pollution is a combination of

To combat this pollution most homes have a range hood installed which is intended to provide ventilation and removal of the pollutants. However:

• many range hoods are low quality, improperly designed, and/or improperly installed
• range hoods are much more capable of ventilating gaseous molecules than particulate matter in the air

Thus, an air purifier equipped with a HEPA filter is a great addition to any kitchen to lower particle concentration in the room. A unit with a good carbon filter is also advised for gas pollutants.

The top rated Winix 5500-2 is again our recommendation. This unit comes equipped with a HEPA filter for particle filtration and a pellet-based carbon filter for superior gas filtration.

Special note on dust mites

Dust vs dust mites

Dust mites are tiny arachnids (they belong to the same class - Arachnida - as spiders, scorpions, and ticks) that live in textiles (any material made of interlacing fibers) like fabric couches, curtains, carpets, and especially mattresses and bedding.

Where do dust mites come from?

The same place all other arachnids come from – the outside of your house. The major problem here is that they’re microscopic which means that you won’t see them coming and you won’t really know if you’re getting rid of them.

And in fact, most people do not see them coming or going. About four out of every five homes in the Unites States have “detectable levels of dust mite allergen in at least one bed”.

Dust mites and dust

Dust mites feed on dust – hence the name – dust mite. They especially like to eat dead human and pet skin cells. This is likely at least part of the reason for the common misconception that dust only comprises dead skin cells:

Dust mites eat dust. Dust mites primarily eat dead skin cells. So the thinking goes that dust must comprise primarily dead skin cells and then it’s not too much of a stretch to say that dust only comprises dead skin cells. Of course, we showed earlier that this isn’t the case – dust is made up of much more than just dead skin cells.

And the truth is that sure, dust mites do love to eat dead skin cells but they will also eat other components of dust including textile and paper fibers, mold, and even their own excrement.

And that is the reason why dust mites are called dust mites – they eat all the different kinds of dust.

Not to mention the fact that dust mites can also be classified as dust themselves. Remember, these are microscopic creatures. A typical dust mite is only about 200 to 300 microns long (and much less wide).

Furthermore, their feces and their exoskeletons (when they die) can also be considered dust particles. Let’s talk more about those now.

The allergy culprits

The dust mite itself is not what triggers allergic reactions. Rather, it’s specific enzymes (proteins) in their feces and, to a lesser extent, their exoskeletons (and/or parts of their exoskeletons) that are the major contributors to allergic reactions in humans.

Let’s take a look at those more closely. First, dust mite feces are about 10 to 40 microns in size. At this size, when disturbed, these particles will not stay airborne very long – minutes at best. Exoskeletons and parts of exoskeletons are usually even larger. A full-size exoskeleton will be just as large as the dust mite itself – about 200 to 300 microns on its longest side. This size particle won’t stay airborne for more than a few seconds.

It’s not surprising then that “most exposure to dust mite allergens occurs while sleeping and when dust is disturbed during bed-making or other movements”.

Our recommendation

According to the NIH (National Institute of Environmental Health Sciences) it’s impossible to completely eliminate dust mites from your home. You can only reduce their total number.

Recall that they live in textiles so you can either

Dust mites also love humidity so reducing humidity in your home can help. Finally, you should clean often – wash your sheets weekly and vacuum frequently.

In terms of air purifiers

Dust mite allergens will only become airborne when disturbed. Running an air purifier in any room with textiles will certainly reduce the presence of dust mite allergens when those textiles are disturbed – eg. walking over carpet, sitting on a couch, changing the sheets (any activity that involves human or pet interaction with the textile).

In Summary

• Dust is everywhere but any airborne dust can immediately be removed from the air with an air purifier equipped with a HEPA filter. Our recommendation is a 250 CFM unit like the Winix 5500-2.
• Cooking generates lots of particles and gases. Again, an air purifier can remove those as well – the unit’s HEPA filter removes the particles and the unit’s carbon filter removes the gases. Again, the Winix 5500-2 is recommended.
• Dust mites eat dust which is why they’re called dust mites. An air purifier can remove dust mite feces and exoskeletons from the air. Granted, they don’t stay airborne for long so an air purifier will only remove them from the air for the few moments to minutes after they’re disturbed from a surface.