Do Air Purifiers Work

Pollen, pollutants, animal dander, and other particles cause millions of people respiratory difficulties. If you suffer from allergies or asthma, consider using an air purifier to clean the air. However, do these devices truly improve your breathing? While an air purifier for smoke can help remove pollutants and other irritants, there are more effective ways to improve the air quality in your home.

How Do Air Purifiers Work

A fan within an air purifier draws air into the appliance. A filter captures contaminants and particles as they enter, effectively removing them from the air. The newly purified air then exits the filter and returns to the chamber.

do air purifiers work

Photo: Amazon

Not all air purifiers can capture all of the pollutants and particulates that circulate through a room, but depending on the type of filter used, they can capture a significant amount of allergens and other undesirable substances.

Numerous air purifiers have HEPA filters that capture dust, pollen, and mold spores. Some air purifiers utilize other filters and technologies to purify the air. Some air purifiers, for instance, utilize ultraviolet germicidal irradiation, where UV bulbs target airborne viruses, bacteria, and fungal spores. Other air purifiers utilize activated carbon filters to capture odor-causing molecules.

Some machines have washable filters, while others use disposable filters that must be replaced every three, six, or twelve months.

Each home air purifier is intended to purify the air in a room of a specific dimension. Some air purifiers may be able to function in rooms measuring 500 square feet or more, while others are designed for spaces measuring no more than 150 square feet.

Are Air Purifiers Worth the Money

Air purifiers can be worthwhile if you have reasonable expectations for what they can accomplish and are willing to pay the costs associated with such a device.

According to the EPA, there are better ways to purify the air in a room than purchasing an air purifier. Attempting to eradicate the source of pollutants and particles should be the first step in enhancing indoor air quality. You should also attempt to improve the room's ventilation. According to the EPA, an air purifier cannot replace the circulation of fresh, clean air from the outdoors into your residence.

Nevertheless, according to the EPA, an air purifier can complement other methods of improving indoor air quality. Before purchasing an air purifier, you should investigate the associated costs. In addition to purchasing the machine, which typically costs several hundred dollars per unit, it may be necessary to replace the filters periodically.

Additionally, using an air purifier may increase your home's energy costs. The EPA estimates that a perpetually operating air purifier may require approximately 450 kWh of electricity per year, which is more than required to power some new refrigerators annually. 

You can reduce these costs by purchasing air purifiers that are at least 25% more energy-efficient than standard models and are ENERGY STAR-certified.

What Do Air Purifiers Filter Out

do air purifiers work

Photo: Amazon

Most air filters on the market are designed to trap particles such as dust, smoke, and pollen, but they do not capture gasses such as VOCs (volatile organic compounds) or radon that can accumulate from adhesives, paints, and cleaning products. This requires an absorbent such as activated carbon. 

The Environmental Protection Agency (EPA) warns that air filter for home are limited in their ability to filter out gasses and that filters must be replaced frequently for optimal performance, typically every three to four months. In addition, purifiers do not capture allergens that are embedded in furniture or flooring.

In addition, the effectiveness of air purifiers in real-world situations is unlikely to match that of controlled laboratory conditions (to which those "99% effectiveness" claims to pertain!). 

Location, installation, discharge rate, and run time will vary, as will the environmental conditions. In addition, ventilation (open or closed windows) and the constant emergence of new particles means that the air may not be as effectively filtered as the manufacturer claims. To remove allergens, bacteria, and viruses from surfaces, you must use disinfectant cleansers and powerful vacuums.

Should I Buy Air Purifiers

Know beforehand that an air purifier is not a panacea. There is scant evidence that air purifiers directly improve health or alleviate allergies and respiratory symptoms. It isn't easy to distinguish the effects of known air-quality pollutants in your residence from those of other environmental and genetic factors. 

For instance, in addition to indoor pollutants, how do your home's furnishings and ventilation impact you? However, if you suffer from allergies or asthma, an air purifier with a HEPA filter may be beneficial as it is effective at removing minute airborne particles.

What is a HEPA Filter?

Air purifiers use high-efficiency particulate air (HEPA) filters to attain a high CADR rating.

These filters can theoretically remove 99.97% or more of airborne particles with a dimension of 0.3 microns, including dust, pollen, mold, and bacteria. According to the EPA, particles larger or smaller than this size are captured with greater efficacy.

The price of HEPA filters varies based on the air purifier you purchase. In addition, HEPA filters are frequently sold in multipacks or combinations with other filter varieties. Typically, a HEPA filter will last approximately one year.

What Is CADR?

The clean air delivery rate, or CADR, quantifies an air purifier's ability to capture and remove specific airborne pollutants, such as dust, pollen, and tobacco.

The Independent Association of Household Appliance Manufacturers defines the CADR standard and is validated by an independent laboratory. Consumers can use the CADR to compare air purifiers and determine which will best purify the air in their homes.

The CADR of an air purifier is typically expressed as three different numbers that indicate the unit's ability to remove dust, pollen, and smoke. The greater the CADR, the more efficient the unit. According to the EPA, the CADR is typically measured when an air purifier operates at maximum speed.


What is a disadvantage of air purifiers?

Aside from the financial investment, there are a few disadvantages to having an air purifier in your residence. Numerous ionizers, particularly older models, can produce ozone during operation, which is known to aggravate asthma.

Are Air Purifiers Beneficial for COVID?

Using HEPA filtration, air purifiers can capture particles as small as the coronavirus. As the transmission rate may be faster than the air purifier's ability to capture particles, its actual effectiveness in preventing someone from contracting the virus remains unknown. 

Therefore, we continue to adhere to the CDC's recommendations regarding the most effective methods for reducing transmission risk and minimizing exposure to the virus.

Is it healthy to use an air purifier daily?

Due to the ubiquitous and ongoing nature of air pollution, it is best to leave your air purifier on all day. There are no perceived disadvantages to continuing to operate your unit; changing the filters regularly can help reduce indoor air pollution.


If you have underlying health issues, such as asthma and allergies, discuss with your doctor methods to improve the air quality in your home to manage your symptoms. You can also search for air purifiers and filters certified by the Asthma and Allergy Foundation of America as asthma- and allergy-friendly. An allergist may also provide you with individualized recommendations.

0 ratings
Vincent David
Vincent David
I am a great believer in the principles of fast, inexpensive and easy design. I am an expert in our own back yard and a master mechanic with an unending love for his tools. I'm also a born-again Christian and after a lifetime of touring, I've found my true home here. I'm a self-taught tinkerer with a passion for small hardware, electronics and the mechanical arts.