How to pollution-proof your house -- for a price
Air purifiers (of all kinds) are the latest appliances that promise to bridge the state’s infrastructural and administrative failings -- for a price.
The air outside may be noxious, but, for those with the means, there are ways in which homes and offices can be pollution-proofed.
Air purifiers (of all kinds) are the latest appliances that promise to bridge the state’s infrastructural and administrative failings -- for a price.
Air purifiers have a a series of filters including a prefilter for larger particles, a HEPA or high-efficiency particulate arresting filter for smaller and deadlier pollutants, and activated carbon for airborne bacteria and volatile compounds.
They have fans that suck in the air in a room, pass it through multiple filters that capture pollutants, particulate matter and allergens, and then pump back clean air. Most air purifiers can capture airborne particles larger than or equal to 0.3 microns. A micron is the standard unit for measuring the size of air particles. Each micron is 1/25,400 of an inch or one millionth of a metre. HEPA filters have ratings, with higher-spec H13 and H14 HEPA filters being medical grade, which means they can capture airborne particles as small as 0.2 microns.
Most affordable consumer purifiers have H10 or H12 rated filters. Premium ones operate with an H13 filter. All HEPA filters have a usable life, post which they must be replaced. Depending on their size and filter capacity, air purifiers range in price from ₹6,000 to ₹2,00,000.
Some consumers question if these devices will do them any good, considering they still spend enough time outside.
“There’s a big understanding gap. It’s a cumulative effect when you’re breathing pollution. The more pollutants go into the lungs, the blacker your lungs get, and they faster they reach a point of failure. Pollutants also go into the bloodstream and affect other organs. If you can avoid breathing pollution for seven or eight hours a day, you are giving those organs respite, making them stronger, versus reducing immunity,” points out Barun Aggarwal, CEO and Founder of air quality experts BreatheEasy Consultants, and author of How to Grow Fresh Air.
Jai Dhar Gupta, CEO of Nirvana Being, a clean air solutions business, illustrates how indoor air composition can be quite dangerous for health. “Indoor air is typically 10 times worse. All outdoor pollutants in ambient air are indoors too, with additional sources such as off-gassing from construction materials, gases and VOCs from housekeeping materials, oil-based particles, smoke from the kitchen, bio-contaminants if someone is unwell, and build up of carbon dioxide through natural process of breathing.”
Nirvana Being has a MESP purifier that replaces HEPA with a Micro-electrostatic Precipitator or MESP filter, which is washable. MESP is a honeycomb structure of metallic tubes that have an insulation coating generating electrical fields within the tubes – pollutants are charged particles and get pulled towards these tubes (eventually stuck).
HEPA filters are a composition of fibers, mostly polypropylene, borosilicate and fiberglass. They cannot be washed, only cleaned occasionally.
It’s also possible to install filters in split airconditioning units.
Indian company Airth along with IIT Kanpur and IISc Bangalore, has developed HEPA filters for split air-conditioning units too, with different configuration for enhanced filtration during higher pollution winter months. These are easy to install, and convert existing ACs into an air purifier for a few thousand rupees.
Breathe Easy’s Aggarwal points out that there is a difference between passive and active air filtration. “Active air filtration includes newer technology like air ionizers, ozonizers, photocatalytic oxidation and electrostatic precipitators. I don’t believe in those technologies, even though they are being sold fairly openly. There are enough negative by-products that are produced for these technologies that can be harmful to human health.”
The best purifiers use passive filtration.
It is important for an air purifier to be an ideal fit for the room size. Purifiers are sold with different cleaning capacity ratings, including CADR, or clean air delivery rate. These ratings are generated in a perfect testing scenario, and for a user, the thumb rule is simple — the larger a purifier and thicker a filter layer, the more effective it will be in larger indoor spaces.
That problem gets compounded in more active rooms, such as a living room, where outside air too may stream in occasionally.
“Most Indian households have significant leakage of air. That can be from windows or doors opening regularly. Air Purifiers work most effective in closed environments,” points out P.K. Jain, Managing Director of Atlanta Healthcare, a leading air quality management company in the country that works with hospitals and commercial establishments.
It is better to err on the side of caution, and upsize for larger rooms.
“Completely pollution-proofing your home might not be entirely feasible, but significantly reducing indoor pollutants is achievable. Air purifiers are a key part of this strategy, effectively removing dust, allergens, smoke, and other airborne particles. However, they work best when combined with other measures including sealing gaps, and maintaining a clean environment,” said Pooja Baid, Chief Marketing Officer at Versuni India Home Solutions, formerly Philips Domestic Appliances.
Air purifiers are not meant to be centralised systems.
There are centralised purification solutions available -- but those for the minority with centralised air conditioning units in their residences, and for commercial establishments.