Yes, as long as you have the right air filters and sufficient air flow.  It can be difficult to compare and HEPA filter performance can vary widely.  That’s why we do air purifier testing.

Here are the Steps:

  1. Start with your indoor air quality concern.  What do you want the air purifier to remove?
  2. From there identify the right air filters for the job.  Keep reading below for easy to follow instructions.
  3. Ensure the air purifier has enough air flow for your room size.
  4. See our test results and ranking of the best air purifiers.

If you are like us you want to know whether an air purifier works.  The goal is have clean air in our homes or office.  So, it makes sense to see what air purification works best in improving our indoor air quality.  We feel this is important since it can improve our long-term health.

That’s why we test.  A lot.

In this article we present some surprising findings from our testing.  We also include feedback from users of the product and research we have found on the subject.

The focus here will be on how well do air purifiers work for allergies, dust, pet hair, pet allergies and tobacco smoke.

If you want to see the ratings of air purifiers you can see how well they work overall.  We test the air flow and filter efficiency to assess how well each room air purifier can remove airborne particles.

Allergies, Dust and Pet Dander

There is no escaping allergies and dust.  They are everywhere as are dust mites and mold spores.  If you have pets you likely have pet dander from hair and feathers.

We have written a lot about the best air purifiers for allergies.

Do air purifiers work for allergens?

The bottom line is there is one type of filter that works best.  It is the HEPA filter.  As we explain in this article about HEPA filter efficiency, it uniquely removes both the small and large allergy particles.

This is important since allergies come in a variety of sizes.  The larger particles settle to the floor relatively fast.  The smaller particles can take hours or days.  You really want to be able to remove both to properly clean the air.

This leads us to the first interesting finding.

Finding #1

Pollen are particles.  So is dust, pet dander, and mold.  They have different particle sizes however it really doesn’t matter since a true HEPA filter can remove all of these.

In the chart below we show the particle sizes for a variety of items.  If you have a true HEPA filter it will remove 99.97% of all particles sized 0.3 microns and larger.

In our testing, we use a laser particle counter and measure each air purifier’s ability to remove these particles.  We found varying levels of performance.  You can see this in the efficiency rating that we give to each air purifier.

What is also amazing is that the efficiency can further improve for particles smaller than the 0.3 micron size.

So, what this means is if you need to remove any airborne particle, go with a HEPA filter.  If you have allergies, asthma, COPD or any other sensitive respiratory condition or are buying an air purifier to feel better then you will want to get a true HEPA filter or better.

In our testing we report on the filter efficiency so you can see how well each air purifier performs.

What do air purifiers help with


A common use of air purifiers is in the removal of smoke.

If you want to learn more about smoke air purifiers we have written a bit about how well they work.

Finding #2

What is interesting about smoke is that it is made up of both particles and gases.  In fact, hundreds of gases.

Smoke is hard to remove.  The reason is because you need multiple technologies to remove it.

While we tout HEPA for the removal of allergies, pet dander, mold, dust mites, etc the fact is it is not good with odors.  It’s pretty terrible.

Odors are gases.  They will pass through a HEPA filter.  It’s like trying to catch water in a strainer.  The filters can’t hold it.  And if they do it will likely release the odor later.

The solution for this is activated carbon filter.  Usually the higher quality and more carbon in the filters, the better.

Tobacco smoke and fumes from paint or cleaning supplies are sources of indoor air pollution.  There are even ultra-fine particles and fumes from laser printers that affect your home indoor air quality.

Although, what we saw in our testing is that an air purifier with a lot of carbon can also have reduced air flow.  You want to make sure there is enough air flowing through the air cleaner for your size room.

The metric for this is called CADR.  It relates to how much filtered air you will get out of the air cleaner.


Besides smoke we have read several customer reviews about the need to remove odors.

Finding #3

Odors are complex.  These gases can be so small and tricky.  What works well for one may not work well for another.

The standard air filtration method is carbon.  For most gases an activated carbon filter does a great job.  However, you need a few pounds or more to effectively removes smells like tobacco smoke.

For some gases, like formaldehyde an active carbon filter alone is not so good.

Formaldehyde is commonly found in building materials.  Think particle boards.  Sometimes it can be in wood flooring.

To remove this requires other filter media.  The most common is called potassium permanganate.

When combined with activated carbon you have a powerful odor remover.


In this article we address whether air purifiers work.

We focused on the areas where air purifiers can work really well.  And highlighted some areas where they are not so effective.

There are other air purifier technologies that we did not discuss since in our testing they did not perform as well.