What should you look for? According to an engineer at Dyson, the air purifier you buy should be capable of doing three things — sensing, capturing and projecting. Sensing means the machine should be smart and intelligent, and it should be able to detect pollution and react automatically to it. It should also be able to switch off once the air in the room has been cleaned. Capturing means the machine should be equipped with the best filtration technology available to ensure that the filters capture a large percentage of the particulates and gases that pass through them. Projection means the clean, filtered air should be projected across the entire room instead of being confined only to the area near the purifier.
Filters hold the key: The higher-end machines, which have a combination of filters, are best-equipped to deal with most types of pollutants. “Consumers need to check if the purifier can provide efficient purification by being capable of removing small particles, viruses, and bacteria. At Philips, our purifiers remove 99.97 per cent indoor air pollutants up to 0.003 microns — pollutants 800 times smaller than PM2.5 — and are certified to remove 99.9 per cent of H1N1 virus and bacteria,” says Dipanjan Chakraborty, business lead, domestic appliances, Philips, Indian sub-continent.
The pre-filter removes dust from the air and provides protection against pet hair. The activated carbon filter eliminates odours and harmful gases from the air. The key component is the HEPA (high-efficiency particulate air) filter which traps pollutants, particles and allergens of even minute size.
Check for cleaning efficiency
: Another key parameter you need to check is the Clean Air Delivery Rate (CADR), which indicates the volume of purified air the machine will deliver at its highest speed setting. “The CADR should ideally be two-thirds of the room size. So, for a room measuring 300-350 sq. ft, a CADR of 200-250 cubic meters an hour (m3/h) is preferable,” says Marzin R. Shroff, managing director and chief executive officer, Eureka Forbes.
Dyson follows a testing method called POLAR for its purifiers, which it claims is superior to the CADR score followed by the industry. The machine should be able to clean up the room within 6-10 minutes.
Quality sensor is a must
: The purifier should also have a good sensor that can measure the quality of air in the room. “Our air purifiers
are equipped with real-time air quality assurance feature that can help you analyse the allergen levels in the air,” says Chakraborty. The machine should also have a low noise level if you are going to use it in your bedroom. Chakraborty suggests buying an app-based model.
According to Shroff, consumers should be mindful of the claims made by the brands and should look out for test certificates and reports which back them. He adds that you should also look for brands with good service network as the HEPA filters need periodic replacement.
Robot purifiers now available: Nowadays, robot purifiers, which are a combination of vacuum cleaner, wet mop, and air purifier have emerged as an option you may consider. “An air purifier is static and can only clean the air in one room unless you move it physically. Our robotic purifier uses self-navigation to go from one room to another and can clean up to 3,500 sq. ft. on a single charge,” says Rajeev Karwal, founder, Milagrow Humantech. A map within an app will show which parts of the house have been covered. These robot purifiers come equipped with HEPA-12 filters that can deal with Covid-19 virus. These filters can be self-cleaned with cold water, which enables them to retain their efficacy for at least one year. If you fill the tank of these robot purifiers with sodium hypo chloride (T, 1 per cent) solution, they will also get rid of the virus that may have settled on the floor of your house.