Home » Air Quality » How Often Should I Change My Air Purifier Filter?

How Often Should I Change My Air Purifier Filter?

As more and more employees shift to a work-from-home environment, many people are turning to air purifiers as a way of keeping the air they breathe clean and free of contaminants. Understanding the answers to air purifier questions can keep you healthy, making you more productive.

How Long Does an Air Purifier Filter Last?


This website is supported by readers. We don't show (annoying) ads, but as an Amazon Associate we earn from qualifying purchases.

What Exactly Is An Air Purifier?

An air purifier is a self-contained motorized fan, designed to push dirty air through a series of filters, capturing the particles that might be harmful to health.

There are all kinds of air purifiers for every kind of room or home imaginable and every one of them requires regular maintenance to function properly. Knowing the basics of air purification systems can ensure that the purifier you purchase lasts.

Coway Filter
Coway Filter

How Do Air Purifiers Work and What Kinds of Filters are Needed?

Most air purifiers push air through a series of High-Efficiency Particle Air (HEPA) filters. The filters are comprised of thinly spun glass and, as a recent study by the EPA suggests, are very effective at reducing bacteria, smoke, pet dander, dust mites and other allergens. Other studies have concluded that a good HEPA unit can reduce between 30 – 50 % of particular contaminants from the air.

There are strict governmental requirements for a filter to be considered HEPA. These finely layered filters are designed to capture around 99.97% of any airborne allergen larger than .3 microns in size.

Air purifiers are very good at capturing pollutant particles that are in the air, however many times allergens (pet dander and dust mites particularly) have settled on surfaces, and are not able to be absorbed. In addition, HEPA filters generally do not filter VOCs (Volatile Organic Compounds), such as odors or scents that are normal byproducts of chemicals or smoke.

To help combat this, some filters add a secondary filtering system made of activated carbon. These types of Activated Carbon filters are designed to force air through carbon packets (reservoirs). The carbon captures larger gas molecules that a pleated HEPA filter cannot restrain.

This Is How Often You Should Be Replacing Air Purifier Filters

The third type of filtering system is Ionic, which ionizes the air particles with a negative electrical charge, forcing the charged particles to clump together. They are then captured by a positive charging plate.

Is There a Specific Rating System for Air Purifier Filters?

Filters are rated by their MERV or how effective the filter is at capturing contaminant particles between 0.3 and 10 microns (µm). The test method was developed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE)  The higher the MERV rating, the better the filter is at capturing particles that may be in the air.

How Long do Filters Last in Air Purifiers?

In general, a HEPA filter should be changed every year; pre-filters last 30 days and carbon filters can last three to six months.

How Long Do Air Purifier Filters Last?

Do Air Purifier Filters Cost A Lot?

Air Purifier filters can range in cost from a few dollars to several hundred, depending on the unit.

Doesn’t the HVAC System Have a Filter and Purify the Air in my Home or Office?

Yes, almost all Heating, Ventilation, and Air Conditioning Systems have a filter that is changed with regular maintenance. Changing the filters in these systems is very easy, and requires a minimum of effort. The trouble with most HVAC systems is that the unit only captures a minimum of particles. If you suffer from allergies or are worried about the quality of the air you and your family are breathing in every day, a room air purifier can help add another line of defense.


Air Recommended Air Purifiers

Our Pick Perfect for bedrooms, playrooms, and living rooms, the Coway Airmega AP-1512HH is one of the best-performing, most durable, and most economical purifiers we’ve tested.

Most Popular The Levoit Core 300 air purifier has some strong suits, but in our opinion it falls short of carving out a meaningful niche for itself. Its ideal use would be in a small bedroom occupied by someone who is sensitive to noise.

Also Great With high end air cleaning performance and a whisper quiet fan, the Winix 5500-2 is the perfect combination of power and finesse. It cleared airborne particulates out of our smokey testing room faster than any other model.

Best of the Best If you have a large space you want to remove irritants from, We recommend the Airmega 400S. All of Coway air purifiers do an excellent job of attacking indoor pollutants, and we highly recommend any of them. The 400S is designed to accommodate large room sizes.

Check Latest Price >



If you have any questions or comments, please add them below in the comment section. Similarly, please let us know if you spot any mistakes or omissions. Thanks!


About the author

Hi I’m Alex, founder of HouseholdMe.com and I’d like to say thank you for dropping by. Like most of you, the first thing I look at before buying something online is reviews or buying guides. By reading what other people say will help me gauge whether or not a product is good or not.  I am trying to help people find answers, solve problems, and get inspired.

Leave a Comment