Buyer's Guide

Do air purifiers work?

It depends on what you're looking for.

If you are looking for cleaner, safer air, then the answer is an easy yes. HEPA filters are independently tested and verified to remove 99.97% of all airborne pollutants, allergens, and other particles 0.3 microns or smaller.

If you are looking for a solution for your allergies and asthma, then the answer is a bit more complicated.


Because you are unique. What might solve your problem might not solve somebody else's and vice-versa.

If you are looking to buy an air purifier to alleviate your allergies and asthma, here are some questions you should ask before making a decision:

What kind of allergies do I suffer from?

How large is my room?

How powerful is the air purifier?


The research says yes. Chances are if you suffer from allergies and asthma, chances are you keep your windows closed to stop more allergens and pollutants from coming inside your house. 

However, this does nothing to remove the allergens and pollutants already in your house. 


Research done by the EPA discovered indoor air was 2-5 times more polluted than air outside.


This poses a real problem for people who spend a lot of time indoors. Luckily, HEPA filters combined with activated carbon filters can remove almost all airborne pollutants. 

Which kind of air purifier is right for me?

Choose Air Filtration Technology

HEPA air purifiers aren't the only air purifiers on the market. The other dominant purifying technology are ionic purifiers. 

Ionic purifiers have trouble removing the smallest, most dangerous particles that gets breathed into our lung – an area where HEPA filters excel.  

For many people, air purifiers are a solution for their allergy or asthma symptoms. However, electrostatic precipitators (a type of ionic purifier), emits ozone.

Ozone is a known irritant on lung and respiratory systems. If you suffer from allergies and respiratory problems such as asthma, stay away. Ozone will only aggravate your symptoms further. 

The other type of ionic purifier are air ionizers. These solutions mask the problem. They "ionize" the pollutants in the air so the pollutants and the air molecules separate. Then the pollutants are attracted to and rest on surfaces such as your floors, your shelves, or your tables. It is very common for these pollutants to rise back up into your air again so this solution isn't often recommended. 

These leaves HEPA filters. 

But not all HEPA air purifiers were create equally. There are quiet purifiers, loud purifiers, weak purifiers, strong purifiers, and so on. 

The Strength of the Purifier

Determining the strength of the purifier is quite easy because it has already been measured and verified by a certified, independent organization, AHAM. 

Each purifier comes with a CADR number or Clean Air Delivery Rate. This measures how effective a purifier is at removing pollutants such as smoke, pollen, and dust. The higher the number, the better. 

Another way to determine how strong a purifier is is to take a look at the recommended room size as well as how many air exchanges per hour it provides.

To relieve allergy and asthma symptoms, it is recommended your purifier provide at least 4 air exchanges per hour. 

How Quiet a Purifier is

Determining how quiet a purifier is can be tricky. Some manufacturers provide you with the sound levels their purifiers emit, but often it is at the lowest fan speed and for best results, the lowest fan speed is not optimal. 

The best bet is to buy a stronger purifier than you need (one that has a larger recommended room size or higher CADR number) and use a lower fan speed. 

This way you don't lose out on your clean air or your peace and quiet.