How Do Air Purifiers Work – The Complete Guide

Manufacturers offer several types of air purification methods. These include filters, ozone generators, ionization, adsorbents, and UV light. Many devices rely on more than one method.

High-quality machines may cost a few hundred dollars to buy. Over time, you will probably need to spend more money running and maintaining your purifier. On the other hand, a good air purifier may offer you the best way to improve indoor air quality and keep your household healthy. That’s why it can pay to learn more about how air purifiers work before deciding which one will help you invest in clean air for you and your family.

What Does an Air Purifier Do and How Does It Work?

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Obviously, some air purifiers work better as air cleaners than others, especially in different situations. Take a moment to learn about various types of air purifiers that you can buy for your home.


The most traditional kinds of air filtration systems use filters. Think of the filters that you use in the air ducts for your home heating and air conditioning system. You may purchase devices that use disposable filters, but some come with washable ones. Denser filter materials can catch smaller particles, and a pleated design may prove more effective than a flat one because it has a larger surface area. To keep your filter effective and efficient, be sure to replace or clean it by the manufacturer’s schedule.

HEPA and ULPA Filters 

HEPA stands for high-efficiency particular air, and HEPA filters must meet Environmental Protection Agency, or EPA, standards. To comply with the HEPA standard, particles of at least .03 microns can’t make it past the barrier more than .03 percent of the time. You might also notice a ULPA, or ultra-low particulate air, standard, which is even stricter. Besides getting used for home air purifiers, some industries rely upon HEPA air purifiers and ULPA filters to keep certain worksites free from contamination and reduce emissions. The EPA suggests cleaning and replacing these filters on schedule to ensure efficiency.

Ionizing Air Purifiers 

Ionizing purifiers work by emitting electricity to give contaminates either a positive or negative charge. The charged particles tend to clump together, making them heavier and likely to fall out of the air. Meanwhile, the device has a positively and negatively charged plate that will attract molecules with the opposite charge. According to the EPA, ion air purifiers are best for small particles, like cigarette smoke, but may not work so well for dust or many other airborne allergens. They may also emit ozone, a controversial byproduct of air purifiers.

Ozone Generators

Somewhat similar to ionizers, ozone generators also produce a charge. Instead of just applying a charge to contaminants, these devices change some oxygen molecules into ozone molecules. These devices are meant to help purify and deodorize. However, the EPA warns that ozone can become a lung irritant and, in larger quantities, even a health hazard.


Note that these are adsorbent and not absorbent. Adsorbent refers to a substance that can trap other substances upon its surface. The most common example is activated charcoal. Its porous surface has plenty of tiny crevices to trap molecules. Chemical and electrostatic reactions also help attract particles and keep them bonded to the surface. Manufacturers also use different methods to produce this charcoal to make it better at attracting certain types of contaminants. According to the EPA, adsorbent air purifiers may offer safe and effective purification of gaseous and organic pollution, such as from cooking or chemicals. Like other filtering products, adsorbents have to be replaced on schedule.

Ultraviolet Light 

The EPA suggests UVGI cleaners to scrub the air of many biological contaminants. Ultraviolet light can help destroy biological impurities such as bacteria, viruses, allergens, and mold in the air. They also suggest using them with a filter and not as a replacement for a filter. Another kind of UV air purifier is called PGO. A PGO works with catalysts to convert gaseous pollutants into harmless byproducts. They don’t work on particles and should also be used with filters.

Which Kind of Air Purifier Works Best?

Indoor air pollution can pose a health risk. Keeping the home clean and ventilating with outside air may help. At the same time, it’s not always possible to clean microscopic harmful particles. Nobody wants to leave a window open if it’s hot or cold enough to need the air conditioner or furnace. Air purifiers may use filters, adsorbents, UV light, electric charges, or sometimes a combination of methods to help improve air quality. Look for high-quality and well-reviewed products that have been designed safely and effectively to address your indoor air pollution problem.

boy celebrating clean air

Are Air Purifiers Worth It?

Air pollution levels have been on the rise for a long time. Not just in the US but globally. The increase in traffic, more strenuous manufacturing processes, and just a steady incline in people are all factors that have added to this dangerous climb. And while we may not be able to control the environment outside of our home, we do have the ability to change it inside.

According to the United States Environmental Protection Agency (EPA), some indoor air pollutant levels are as much as five times higher than outdoor air concentration levels. And when you spend a good portion of your life at home, that’s quite a scary fact to think about, especially for allergy sufferers or those with any pre-existing breathing problems. However, there are ways to improve these statistics, one of which is through the use of an air purifier.

What Are Air Purifiers Designed to Do?

The ultimate goal of an air purifier is to improve the overall air quality within the home. It’s essentially a portable air cleaning system.

Even in the most immaculate homes, dust, mold spores, and other harmful allergens accumulate, causing the air quality to diminish. This is something that can’t be helped. But what can be helped is the level at which this air is filtered, and that’s what air purifiers do. Air purifiers work by taking regular air in via a fan and filtering it through either one or several filters. As the air passes through these filters, any dust particles or pollutants are trapped, and clean air is expelled.

There are many different air purifiers on the market today. However, one thing almost all of them have in common is the filtration system. In most models, you’ll find a pre-filter that tackles the larger particles, while a high-efficiency particulate air (HEPA) filter or HEPA-type filter takes care of the smaller ones. Some air purifiers also include an activated carbon filter as part of their design, which helps to reduce unpleasant odors massively.

An air cleaner works extremely well, provided you maintain it regularly. This typically involves replacing the filter(s) regularly. However, the frequency in which these need to be replaced will vary across models and largely depend on usage. So, just be sure to follow the manufacturer’s advice on maintenance.

Some air purifiers use reusable air filters, which are extremely effective at removing large particles such as pollen and dust mites. These filters can be removed easily and washed as often as needed. The downside is in order to keep them working most efficiently, they do need a lot of regular maintenance.

Do Air Purifiers Work?

There’s a lot of proven science behind the effectiveness of air purifiers, most of which comes down to true HEPA filters. These filters are now an industry standard, and any air purifier not fitted with one should be approached with extreme caution.

HEPA filters are so effective because they use a dense arrangement of fibers to capture airborne particles from the air. Using an air purifier fitted with one of these filters in an optimal location will improve the air quality within the home ten-fold.

Here Are Just Some of the Many Benefits to be Found From Using a Good Air Purifier:

Significantly Reduces Dust Levels and Allergens

If you’re asthmatic or suffer from any kind of respiratory condition, then living in a dusty environment can be extremely dangerous. The same goes for those with dust or pet allergies. However, by using a decent air purifier, dust levels will reduce significantly, along with the number of triggering allergens. Your home will have cleaner air, and you will find yourself being able to breathe more easily. If you keep any furry friends in your home, various air purifiers are available specifically for dealing with pet dander and odors. So not only will it help you breathe better, but it will also help your home smell better.

Absorbs Damaging Chemicals

Volatile organic compounds, or VOCs for short, are essentially the gases that are emitted from a number of both indoor and outdoor sources. However, concentrations of VOCs are much higher indoors than outdoors and can come from a variety of everyday items such as cleaning supplies or paint. Having an air purifier in the home, particularly one fitted with a charcoal-based activation filter, can help absorb some of these harmful irritants, giving you much better air quality within the home.

Improve on General Household Smells

It’s not just pets that produce terrible smells. Odors in the home can come from various sources, including pungent foods, smoke particles, and dirty kids. While lighting a candle or opening a window may help to ease the whiff a little, a good air purifier will eliminate it entirely.

Are There Other Ways to Improve Air Quality in a Home?

Having good quality air to breathe is not only our right as a human, but it’s essential in order to maintain a healthy life. While an air purifier is the best solution, there are a number of other ways to improve the air quality within your home:

Ventilation is Vital

Opening a window may seem counterproductive when trying to get rid of harmful pollutants. However, in the absence of an air purifier, having the windows open prevents dust mites and allergens from building up. If at all possible, try and open windows on both sides of the room. This will create a stronger cross draft, making it more difficult for air irritants to settle.

Plants Are More Than Just Decoration

You may be surprised to know that plants have some amazing qualities for improving air quality. In 1989, the National Aeronautics and Space Administration (NASA) teamed up with the Associated Landscape Contractors of America (ALCA) to conduct the Clean Air Study. It was essentially a project to find ways to clean the air in space stations. Researchers discovered that there are a number of common indoor plants that may help to do this, including bamboo Palm and English Ivy. So go green and bring a few houseplants into the fold.

Vacuum Regularly

Vacuuming is another inexpensive way of controlling the number of dust particles that accumulate within the home. As most people already own a vacuum, it’s no extra expense to simply use the one you have. If, however, you are looking for an upgrade, try and go for one that’s HEPA-certified. At least then you will have the added benefit of a decent filter.

So Are Air Purifiers Worth It & Do You Need One?

Absolutely! Regardless of whether you suffer from any respiratory problems or allergies, a good air purifier will not only improve the quality of the air you breathe, but it will help to improve the quality of your life too.  These appliances are not gimmicks and should not be seen as just another fad. There has been a lot of time and money spent on researching the benefits of using these appliances, particularly in conjunction with the HEPA air filter. And each and every time, research shows a clear reduction in the harmful irritants, pollutants, dust, and other particles in the air while using an air purifier.

While there may be a cost in the initial purchasing of an air purifier, you will need to keep replacing or cleaning the filter regularly, which may involve an additional cost. However, the health benefits to be seen from having one in your home will largely outweigh any expenditure. At the end of the day, there is no price to be put on yours or your loved ones’ lives. And if you can improve your indoor air quality significantly with just a small investment, surely, it’s worth it.

In 2018 alone, U.S. air purifier sales increased by a million units and can be found in at least one-quarter of American homes. Since indoor air can contain up to five times as many contaminants as outdoor air, it’s not hard to explain the popularity of these devices.