Air purifier: An investment in health where price point takes a backseat

Air quality impacts not just the lungs but other organs too, apart from devastating overall well-being. Choose an air purifier that specifically addresses the requirements of your living space

9 min read Last Updated : Dec 08 2019 | 9:24 PM IST

Ravi Meattle is a stickler for hygiene, wellness and good living. This winter, the 73-year-old resident of Central Delhi has been taking great care to ensure his air purifier is working fine. Meattle gets the gadget's filters vacuum-cleaned every week so that they are able to absorb the dust and pollutants that he says would otherwise have settled on his lungs, He adds that with the kind of Air Quality Index (AQI) levels prevailing in Delhi, he discards the filter within six months and buys a new one, even if it sets him back by Rs 6,000- Rs 8,000. But that is an investment in health for Meattle, who has chronic respiratory problems. Separately, he has bought a pollution metre for Rs 10,000 to monitor the AQI inside his house, saying it gives him real-time information on the space in which he is living as against the generic data published on websites. And he switches on the air purifier every time the AQI inside the house crosses 100.

"Nowadays you don’t just feel pollution, but you 'see', 'smell', and 'taste' it too, and we often wonder if we can migrate to escape this gas chamber," says 42-year-old Aradhana Ghosh, a mother of two young children, who has installed air purifiers in both the bedrooms in her house. She has also stopped her children from playing outdoors, insisting they play board games inside.

Is this an over-reaction of sorts, where the urban elite are sanitising themselves, their families and changing their lifestyle? No it isn't, says Abi Stringer, Design Engineer, Research Design and Development, Dyson, who shares how Bangkok, as recently as January 2019, declared an emergency when the AQI hit 179 and the State announced the closure of all schools. Stringer says in London, where she resides, people start exploring air purifiers as soon as the reading hits 50 or 60, adding that it is unbelievable that the AQI has to cross 500 in Delhi before the authorities raise an alarm.

After Diwali, the Capital broke all records when several areas recorded an AQI of 999, beyond which reading is not possible. In comparison, the air quality guidelines issued by the World Health Organization state that PM2.5 should not exceed 25 grams per cubic metre, 24 hour-mean, which is a clear indication that Indian cities are miles away from ideal. In fact, as many as 14 of the 15 most polluted cities in the world are in India, a study reveals.

Little wonder then, that the unprecedented levels of pollution have fostered a spike in the sales of air purifiers in recent years. According to Mahesh Gupta, CMD, Kent RO, “We have seen that in the past four years, there has been a sudden surge in the demand for air purifiers during the smog situation in Delhi. At Kent, we have registered a 50 per cent growth in sales over the same period last year.” There is widespread usage of air purifiers not just in the Delhi-NCR region, but also in neighbouring states and cities such as Chandigarh, Ludhiana, Jalandhar, and parts of Haryana. Says Gupta, “Earlier 70 per cent of the sales were in Delhi-NCR. However, this year we have seen a surge in demand from other cities also.” While the residential segment—especially homes with infants and senior citizens—is the biggest driver of demand, corporate offices have also begun buying these devices for their CXOs, and demand is emanating from private schools and hospitals as well.

The market is replete with choices that come in a price range of Rs 6,000 to over Rs one lakh. However, increasing competition in the air purifier market is bringing down prices. Some of the major players operating in the Indian market are Philips India Ltd, Sharp Business Systems (India) Pvt Ltd, Blueair India Pvt Ltd, Eureka Forbes Ltd, Dyson Technology India Pvt Ltd, Honeywell India Pvt Ltd, LG Electronics India Pvt Ltd, Kent R O Systems Ltd, Atlanta Healthcare, Panasonic India Pvt Ltd, Crusaders Technologies India Pvt. Ltd, and Daikin Air Conditioning India Pvt Ltd.

How do you choose?

Often price is the first and last determinant of what to buy. However, one must assess the filtration system, which is the very core of a purifier. Several kinds of filtration are available in the market. One is where ultraviolet light uses electromagnetic radiation to destroy bacteria, viruses and mold. However, this variant does not remove dust, allergens or particles in the air. In another, activated carbon filters react chemically with pollutants to clear smoke, odours and gases from the air, but are unable to filter out very fine particles that can be very harmful. In a third variant, air ionisers work by sending out a stream of charged ions to attract dust and allergens. However, they can produce ozone as a by-product. Ozone is a respiratory irritant and a component of smog. Then you have HEPA (high-efficiency particulate air) purifiers, which work by trapping pollutants and fine particles across a range of different sizes. These include pollen, bacteria, mold, dust mite debris and pet dander. They do not, however, remove volatile organic compounds such as formaldehyde, benzene or nitrogen dioxide. It is also worth noting that not all HEPA filters are equally efficient. Some are able to capture ultrafine particles, while others aren't.

The best purifiers in the market combine HEPA filters with activated carbon, enabling them to remove both particulate matter and volatile organic compounds. Advanced air purifiers available in the market are the ideal solution to deal with the current air pollution problem, as they use a combination of purification systems as well as a set of filters. They have a four-stage filtration process—primary filter, carbon, HEPA and ionizer—to filter out air and make it 100 per cent clean and pure. However one needs to consider the size of the room. Such purifiers have the ability to accurately monitor and measure the PM 2.5 content in the air on a real-time basis and display it on the screen.

When selecting an air purifier, you must look for what it targets—normally the culprits are PM2.5, PM10, volatile organic compounds and nitrogen oxide. The most commonly measured size is 2.5 microns and particles of this size are referred to as PM2.5. Most filters tend to capture this. Some purifiers can capture particles down to PM2.5, while others go beyond, and can trap particles as small as PM0.1, which impacts not just lungs but also enters the bloodstream.

One must choose an air purifier with an accurate sensing system—something that tells you about the air quality around you. Most entry-level purifiers have a basic LED indicator system for air quality—avoid these if possible. The newer models of purifiers come with a digital display that shows you the actual air quality level in your room. This makes it easy to make out when you need to run the purifier at the highest level and when you can turn it down.

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A key issue one must consider is what the minimum size of air purifier should be and how big a room it can serve. A 600 square-foot room will require 40 watts at top speed, says a spokesperson from Dyson. But even the most powerful purifier may not work even if the room size is small, the walls are thin, or the windows are susceptible to leakage by outdoor air. So the room structure needs to be examined. Here is one guidance. “If your room measures 150 sq ft, get an air purifier that indicates a rating that is at or just above this number. A 200 or 250 sq ft rating would be just as efficient as one that measures 150 sq ft exactly,” says a spokesperson from Kent.

Look for efficiency. Rahul Aeron, Assistant VP-Sales, Desiccant Rotors International Pvt Ltd (DRI), Pahwa group, says that since the acceptable levels of PM2.5 as per UN guidelines is 25 g/m3, 24-hour mean, but let’s say in Delhi today PM2.5 is 500, then you need to stop 475 particles, which means that the purifier has to work at an efficiency level of 90-95 per cent. He adds that purification is relatively easier in commercial spaces, where there is centralised air conditioning, such as The Oberoi Delhi, where his company recently installed 40 units.

Maintenance is important. Regular cleaning of the filter and replacement once in every 6-12 months, depending upon usage, is recommended. The filter may cost anything between Rs 4,000 and Rs 8,000. The filter of most air purifiers can be vacuum cleaned.

The air pollution inside our homes can be as bad, if not worse than the outside air, says Dr Sandeep Nayar, Director & HOD, Centre for Chest & Respiratory Diseases, BLK Hospital. He feels that indoor pollution can be made worse due to indoor sources. These potentially harmful pollutants are as small as PM0.1 and remain suspended in indoor air. He says one of the things his department advises patients is to do away with carpets, which are a reserve for severe dust mite allergens, and go for wet mopping instead. Also compressed wood is a storehouse of VOCs (volatile organic compounds) which are carcinogenic. Everything from perfumes to nail polishes contains lead and one must even avoid lighting incense sticks. The air we breathe has an impact not just on respiratory health but can affect everything from head to toe, impairing cognitive ability, fostering heart ailments and impacting one's overall well-being.