As we now know, COVID-19 is caused by the Coronavirus 2 (SARS-CoV-2). When the virus contacts mucous membranes, like those in the eyes, nose, and mouth, the person gets infected. Research shows that the virus can live in the air for up to 3 hours. It can get into your lungs if an infected person breathes out and you breathe that air in.
As many of us are forced to stay at home, maintaining indoor air quality is of prime importance. That’s the job of air purifiers or cleaners. But can they protect us against COVID-19?
According to the US Environmental Protection Agency, simple preventive measures such as wearing masks, practicing social distancing, and opening windows to let a draft flow through are the best ways to avoid airborne transmission indoors. But the US Centres for Disease Control and Prevention (CDC) adds that “when used properly, air purifiers can help reduce airborne contaminants, including viruses, in a home or confined space.”
Not the first line of defence
Air purifiers are not meant to be the first line of defence against viruses like COVID-19 where the transmission is through Droplet spray in short range or direct contact. But an air purifier that can filter airborne ultrafine particles can help prevent Aerosol in long-range transmission (airborne transmission).
According to IQAir, a Swiss-based air quality technology company, in order for an air cleaner to be effective in removing viruses from the air, it must be able to remove small airborne particles (in the size range of 0.1-1 um). Manufacturers report this capability in several ways. In some cases, they may indicate particle removal efficiency for specific particle sizes (e.g. “removes 99.9% of particles as small as 0.3 um”).
Many manufacturers use the Clean Air Delivery Rate (CADR) rating system to rate air cleaner performance. CADR measures an air cleaner's effectiveness based on room space and the volume of clean air produced per minute. This shows how well dust, pollen and smoke, the three most common indoor air pollutants are removed from the air you breathe. The higher the CADR test numbers, the better the unit’s overall ability to clean indoor air.
Others indicate they use High Efficiency Particulate Air (HEPA) filters.
Filtration is the most common approach used to capture airborne SARS-CoV-2, and it generally gets the thumbs up from scientists and regulatory agencies. Many devices rely on the HEPA filter, which traces its origins back to the gas masks of World War II.
HEPA and HyperHEPA filters are mechanical air purification filters. Mechanical filtration is the safest and most effective method for removal of airborne particles from the air.
Using a fan, HEPA purifiers begin by drawing polluted air into the device. From here, the air passes through a filter, usually made of fiberglass, where airborne particles become ensnared in a maze-like tangle of fibres.
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The other common type of air purifiers are UV purifiers. Like HEPA purifiers, UV purifiers begin by sucking air into the device. They then expose the air to a UV lamp, which generally produces UV-C light. Through a process of ultraviolet germicidal irradiation (UVGI), the UV light breaks down the chemical bonds formed between DNA molecules, which renders viruses inactive and can kill bacteria and fungi. But in most of the products, UV filters are sold in combination with HEPA filters.
Things to remember
Viruses can be captured by filters, but this doesn’t guarantee that you’re fully protected – airborne transmission is only one way that viruses are spread like in the case of COVID-19. Even the most efficient air purifiers are not 100% effective at preventing the spread of viruses.
Place the air purifier in the room you spend the most time in or where vulnerable people spend the most time. To help reduce risks of airborne transmission, direct the airflow of the air purifier so that is does not blow directly from one person to another.
Something is in the air
The pandemic has seen a spurt of companies offering air purification solutions that tackle the COVID-19 virus.
Zeco Aircon has introduced an air purification technology that claims to neutralise the SARS-CoV-2 virus that causes COVID-19. The Plug & Play product is designed with RGF's patent PHI technology. The technology, developed by a US firm RGF Environmental Group and licensed to Zeco Aircon, uses ionised hydrogen peroxide for destroying germs and deadly viruses.
Dr Yogi Goswami’s breakthrough purification technology, PECO (Photo Electrochemical Oxidation), now powers all Molekule air purifiers. The portable Molekule Air Mini (On sale with a 12% discount) can help remove and inactivate viruses. Single-pass efficiency testing showed deactivation of bovine coronavirus of up to 99% in 2 hours. It is available on Amazon.
The IQAir HealthPro Series features HyperHEPA filtration technology for superior airborne particle removal, tested and certified by an independent third-party lab to effectively filter harmful ultrafine pollution particles (UFPs) down to 0.003 microns in size - 100 times smaller than what is achieved with ordinary air filtration technology and 10 times smaller than a virus.