Do Air Purifiers Actually Work? – Everything You Need To Know

Do Air Purifiers Actually Work? – Everything You Need To Know

Experts weigh in on whether or not purifiers can effectively filter out bacteria, dust, smoke, and mould, among other contaminants. Find out with us Do Air Purifiers Actually Work?

An air purifier’s promise is alluring: A device designed to purify the air in your house, eliminating contaminants such as odours, smoke, dust, and pet dander. We understand that indoor air can contain up to five times more of certain contaminants than outdoor air. Indeed, air purifiers can mitigate a portion of the danger caused by air pollution and indoor activities. In actuality, however, not all air purifiers live up to their marketing claims.

How do Air Purifiers work?

Working of Air Purifiers explained

Typically, air purifiers have a filter or many filters and a fan that draws in and circulates air. They remove the pollutants and particles from the air as it passes through the filter, and then pushes clean air back into the living room. Typically, paper, fibre (typically fibreglass), or mesh make up the filters and you must change them frequently.

The frequency of filter replacement varies depending on the type and usage of the purifier. Some filters are reusable and washable, but they require diligent maintenance, thus they are typically absent from the most efficient air purifiers. In general, reusable filters are effective in removing bigger airborne particles, such as dust mites and pollen. There are other UV (ultraviolet light) filters on the market, which frequently promise to kill biological contaminants such as mould or bacteria, but many require higher wattage and greater exposure to be successful (not to mention some bacteria are UV-resistant).

In addition to the initial purchase price of an air purifier, you must also consider the operational costs and filter replacement prices. Considering that air purifiers must be on continuously to be effective, annual operating expenses can easily exceed $50. Filter changes might cost more than $100 annually.

Some air purifiers employ ionisers to attract particles such as static – negative ions bind to dust and allergies, causing them to settle out of the air. If you are keen in purchasing an air cleaner that utilises ionisers, ensure that it does not produce excessive amounts of ozone because it can cause asthma.

What are air purifiers supposed to filter out — and do they actually do it?

Most filters on the market are designed to trap particles such as dust, smoke, and pollen, but they do not capture gases such as VOCs (volatile organic compounds) or radon that can accumulate from adhesives, paints, and cleaning agents. This requires an absorbent such as activated carbon. In reality, the Environmental Protection Agency (EPA) warns that air purifiers are restricted in their ability to filter out gases and that filters must be replaced frequently for maximum performance, typically every three to four months. Moreover, purifiers do not collect allergens that are embedded in furniture or flooring.

In addition, the effectiveness of air purifiers in real-world scenarios is unlikely to match that of controlled laboratory conditions (to which those “99 percent effectiveness” claims refer!). Location, installation, flow rate, and run time will vary, as will the environmental circumstances. In addition, ventilation (open or closed windows) and the ongoing emergence of new particles mean that the air may not be as well filtered as the manufacturer says. To remove allergies, bacteria, and viruses from surfaces, you must use disinfectant cleaners and/or powerful vacuums.

Can air purifiers filter the outdoor air that enters your home?

Some models may be able to target unhealthy air that seeps into your apartment or home, particularly if you live in a region affected by pollution or a natural disaster. According to Ryan Roten, D.O., an emergency medicine physician at Redlands Community Hospital in California, most individuals shouldn’t be concerned about exposure to transient pollutants like smoke or exhaust in the air outside your home, as they disperse with time.

“In the short term, people will primarily experience asthma-like symptoms or symptoms closer to allergies or sinusitis, such as a stuffy nose and a bit of a cough,” says Dr. Roten, who has been treating patients with underlying respiratory illnesses as wildfires rage on the West Coast and air quality reaches record lows. If the smoke is dense enough, carbon dioxide can cause headaches, and individuals with asthma or COPD can experience a worsening of their symptoms.

Sometimes, non-organic air contaminants, such as volatile organic compounds (VOCs), might originate from outside your home. “There are numerous scenarios involving structural fires in which inhaling huge quantities of smoke might cause cyanide toxicity. Those individuals are transported promptly to emergency departments, “Dr. Roten explains. Pollution, smoke, and transitory poor air quality are typically not a constant problem for spectators.

What is a HEPA filter?

Hepa Filter

High Efficiency Particulate Air (HEPA) is an acronym for High Efficiency Particulate Air. HEPA filters catch particles of variable sizes within a multi-layered netting typically composed of extremely tiny fibreglass threads (far thinner than a human hair!) with varying sized gaps.

The fan of the air purifier draws air into the filter, where it traps the particles. Larger particles (those that are larger than the fibres) are captured by impaction (the particle collides with the fibre), mid-sized particles are captured by interception (the particle hits the fibre and is captured), and ultra-fine particles are captured by diffusion (while zig-zagging the particle will eventually hit and stick to the fiber).

Can air purifiers capture the coronavirus?

Using HEPA filters, air purifiers may collect particles as small as the coronavirus. As the rate of transmission may be faster than the air purifier’s ability to trap particles, its real effectiveness in preventing someone from contracting the virus remains unknown. Therefore, we continue to urge adhering to the CDC’s recommendations for the most effective strategies for lowering transmission risk and minimising exposure to the virus.

So… should I buy an air purifier?

Know beforehand that an air purifier is not a panacea. There is less evidence that air purifiers promote health or reduce allergies and respiratory symptoms directly. It is difficult to distinguish the impacts of established air-quality pollutants in your home from those of additional environmental and genetic factors. (For instance, in addition to indoor contaminants, how do your home’s decor and ventilation affect 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 small airborne particles.

What should I look for in an air purifier?

  • CADR (clean-air delivery rate) rating: This metric measures the purifier’s speed at removing smoke, dust, and pollen. Consider a CADR of at least 300; anything above 350 is excellent.
  • Size guidelines: For optimal effectiveness, you need a model that will operate in your space. If you wish to use it at a lower, quieter level, select a model that is built for a wider area than the one you are installing it for.
  • Verification from AHAM (Association of Home Appliance Manufacturers: AHAM’s standards are intended to guarantee the safety, efficiency, and performance of a variety of home care appliances, including air purifiers. The standards offer manufacturers and consumers a shared understanding to facilitate the simplification of the purchasing process. Most respectable air purifiers have participated in this certification programme, which frequently provides a CADR rating and size recommendations
  • True HEPA: True HEPA filters successfully remove ultrafine particles (think: dust, dander, pollen, mould and other common allergens in the home). In a laboratory setting, the unit must be able to remove at least 99.97 percent of particles measuring 0.3 microns in diameter. Keep in mind that the actual effectiveness of these devices in real-world circumstances would be far lower, as new contaminants are continually developing.

What are other ways I can improve the air quality in my home?

The best recommendation is to eliminate the cause of indoor air pollution and to ventilate the home. If you want to supplement the job of your air purifier or test if you can go without one, we suggest taking the following techniques to reduce indoor air irritants:

  • If it’s safe, leave your windows open to keep irritants out (especially when air purifiers aren’t running). Consider opening windows on opposite sides of the room if possible to create a stronger cross draft.
  • Maintain a regular vacuuming schedule. A sealed, bagged and HEPA-certified vacuum is the best way to go if you’re in the market for one. It traps the dust instead of sent back into the atmosphere. 
  • Change air filters on a regular basis to properly maintain HVAC equipment and enhance its efficacy. Dr. Roten adds that getting a HEPA-specific filter for your circulation system can give further filtration: “It will recirculate the air in your home somewhat better with each pass.”
  • If possible, use exhaust fans in the kitchen (and the bathroom and laundry). Turn it on before preheating the oven or lighting the burners, and leave it on for a few minutes after cooking is complete.
  • Reduce the use of candles and wood fires, and prohibit smoking indoors. Reducing polluting sources is a foolproof method for enhancing air quality.


Due to the increasing level of pollution and its harmful effects on health, it is crucial that every household install an air purifier. HEPA air purifiers capture and trap even the tiniest particles to make the air in your home safe. You can check out PurifAir Portable Air Purifier for you.