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Can Air Purifiers Make Allergies Worse?

Last updated November 3, 2021

This post may contain affiliate links.

Author avatar Danny Ashton

Danny as been writing about air purifiers for 10+ years. He is a major fan of home technology, which makes him the perfect person to test and evaluate products for HouseFresh

TLDR: In some cases, the use of an air purifier can cause your allergies to become worse instead of better. In most cases, this is due to ionizer units that are malfunctioning and end up increase the number of allergens and dust in the air without removal.

What are air purifiers meant to do?

Air Purifiers are used for allergies such as dust mite, pollen, and pet allergies, and dander. The science is fairly simple, air purifiers remove the pollutant from the air using a filter of some kind. 

The most widely regarded technology is HEPA as there have been numerous scientific studies using double-blind testing with the first studies from 1990 and there has also been a ton of studies even recently looking at how effective HEPA is for Covid19. also be sure to check out our list of the best medical grade purifiers as of 2021.

I am a big fan of HEPA air purifiers for dealing with things like vapor from a vape pen then check out our guide to the best air purifiers for vaping and we even did a guide on the best purifier for weed smoke (If you get a powerful enough unit.)

These units don’t need to be super loud to work well, in our list of the best quiet air purifiers we looked at just those that don’t produce a ton of sound when they are in use.

So what type of air purifiers make allergies worse?

in simple terms: Ionizer air purifiers

Back in the day, I used to answer questions on Yahoo Answers, and very often people would ask why their air purifier is actually making their allergy worse instead of helping. One young woman bought an ionizer air purifier and then told us how it made her allergies worse for the next 6 months. It was only when this purifier broke that her allergies got better.

Now the problem with many ionizer air purifiers is they will stir up the dust/pollen/pet dander in your room and bring it out of the areas it has been hiding. The Ionization process will then charge the allergen particles and make them heavier. However, if the air purifier has a limited ability to filter the allergens then the problem has only been made worse. Allergens that are stuck in your carpet or behind objects do not cause as many problems as the allergens in the air. It’s the reason why many of us even with no allergies start sneezing after we have been dusting our rooms.

Another problem with using an air purifier for allergies is that some of the cheaper ionizer based models actually produce ozone which can trigger allergies in some people [we have a list of the best ozone generators if have a job that requires it]. In once case – The ionic breeze air purifier produced as much ozone as the amount found during high smog season in downtown LA! Any air purifier that produces any sort of ozone should be ignored by someone looking to remove allergens from the air.

So what type of air purifiers do work for allergies?

It might sound like I am telling you that an air purifier is useless for allergies but I’m not. In fact, I helped to reduce my symptoms caused by my dust mite allergy by using an air purifier. However, it took me many different models and lots of $$ to find one that actually worked. So I have put together a list of things to look for if you really want an allergy air purifier:

1. No Ozone Production – check with independent results to see how much ozone is produced. Even better, check out some the best ozone free air purifiers on the market.

2. Needs to be able to deal with a room sized at least 500 square feet – but preferable more than 1000 feet.

3. Needs to be able to remove 99.7% of particles bigger than 0.3 microns. In most cases this will require a true HEPA filter. Again check independent results to see how it works both out of the box and after 6 months.

4. Always choose an air purifier that comes with a pre-filter. Pre Filters stop big particles such as dust, pet hair, and general dirt. With a pre-filter, it will mean that you won’t have to buy as many costly replacement HEPA filters. Even the sub $100 Levoit 300 comes with a pre-filter and perfroms well considering its low price.

5. Try to find an air purifier that has a silent sleep mode as you will want to keep the machine running whilst you sleep. If you really want to clean just your personal space then be sure to check out what we reccomend is the best personal air purifier on the market as of 2021.

Tips to make sure your air purifier helps allergies and doesn’t make them worse

  • Be sure to check if your filters need replacing. A big issue is that people forget that filters need replacing either every 12 months (for cheaper units) or every 5 years for units like the Coway (more $$)
  • Make sure that you only go for an air purifier with a true HEPA filter or equivalent. The main issue for allergy sufferers is the pet and pollen dander which will get caught up in HEPA filters as the holes are small enough to let in air but can capture bigger particles like tree pollen or pet dander.
  • Don’t make the mistake of using a small unit in a large space. Many of the cheaper air purifiers are only built to deal with the air in a small room. If you take one of these units and place it in your large living room – the unit will become overwhelmed and won’t be able to remove the allergen causing particles from your home.

If you are looking for an air purifier that won’t make allergies worse but can significantly reduce the amount of dust and pet dander then be sure to check the list below of our recommendations.

As with all of the air purifier review recommendations we make, we have identified the best deals available right now for 2020 that are in stock and have available replacement filters.

All of the units featured include a true HEPA filter and activated Carbon. As always if you have a very large room or bigger use case – always look to go for our bigger room options.

We have also analyses reviews to identify if any paid or manipulative reviews have been used to artificially inflate the customer’s recommendation score.

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Last update on 2021-11-11 / Affiliate links / Images from Amazon Product Advertising API