Updated: November 4, 2019 7:12:54 pm
Air pollution levels in Delhi and most other North Indian cities remains at hazardous levels. The level of PM 2.5 or particulate matter at the size of 2.5 microns — which is very, very small in size and easily settles in our lungs to cause breathing difficulties and other illness — remains above 900 ug per cubic metre in some parts of the city. For the record, WHO considers 25 ug per cubic metre as the safe limit for PM 2.5. The annual winter pollution season also means it is time to bring out the air purifiers, though as some users have shown on Twitter, the intense smog means that even these are struggling.
When it comes to air purifiers, there are some aspects to keep in mind, which can help ensure that the air in your home at least gets filtered. We list out the pointers to keep in mind before hitting buy on an air purifier, and some air purifiers to consider for your home, across budgets.
HEPA, EPA filters in the Air Purifier
This is really the technology that filters out the PM 2.5 and PM 10 particles, which are the biggest culprits in Delhi’s air pollution crisis right now. HEPA filters stand for High Efficiency Particle Arrestance (HEPA) filters and these can trap particles as small as 0.3 microns. Most air purifiers, be it from brands like Xiaomi or Philips or Honeywell or Sharp, come with a HEPA filter.
But before buying, check if the HEPA filter is capable of removing the 0.3 micron particles. Some air purifiers also come with a live monitor, which shows the PM 2.5 levels in the room, and whether it is dropping or increasing. Some rely on simple light-based indicators to show what the levels are; red usually indicates the situation is really bad, blue means it is safe, orange often means the levels are high, but not as bad.
There are also EPA filters, which is present on the new Mi Air Purifier 2S, though these are believed to be less effective than HEPA filters. But EPA filters can also remove 2.5 micron particles along with other pollutants in the air, such as pet dander.
Other filters in the Air Purifier
While the HEPA Filter removes particulate matter, which is causing the most damage right now, some filters also come with other layers of filtration which can remove odour, bacteria, germs present in the air. These could be helpful for people who suffer from allergies or asthma. A carbon filter usually removes odour. Some air purifier companies like Sharp claim to come with Plasmacluster Ion technology, which they claim can get rid of all kinds of bacteria and fungus.
CADR stands for Clean Air Delivery Rate and this is important. This is usually mentioned in cubic feet per minute, and you should check this for your room. For instance, if you have a really big bedroom or living room, then one air purifier might not be enough to keep it clean, at least in these conditions. Companies will also mention the ideal room size for the air purifier, so double-check this before buying one as well. An air purifier that is effective in your bedroom, might be less effective in a bigger room.
Getting the most out of the Air Purifier
If you keep an Air Purifier in a room where the windows and doors are open all the time, the effectiveness will go down. It will struggle to keep the particulate matter down, which is the major concern right now given the smog that has enveloped most of North India. Keep the doors and windows sealed shut for a majority of the time, especially in the room where you intend to run the air purifier. Bedrooms can be sealed with the air purifier left on for some time to bring the levels down.
However, when the pollution levels are really high, even if the purifier works over time it might come down to levels that are still considered quite high.
Check if replacement filters are available
This is another important part before hitting buying on an air purifier. Make sure the company is selling replacement filters for that particular model before buying. Brands like Xiaomi, Philips do offer replacement filters and given the pollution levels right now it would be best to stock up on these, because these might get out of stock soon. The life of the HEPA or EPA filter is likely to be two-three months in these levels of pollutions given some might be running them 24/7, though some air purifiers also display an alert when it is time to change the filter.
Xiaomi’s Mi Air Purifier series
Xiaomi has two main air purifiers available in India. The reason these stand out is because of the price. The Mi Air Purifier 2S costs Rs 8,999, while the Mi Air Purifier 2C costs Rs 6,499. The 2C air purifier cannot connect to WiFi and Mi Home app nor does it have an in-built monitor to show the PM2.5 levels. The Mi Air Purifier 2S has a CADR rate of 310 cubic metre per hour. Another difference is that the Mi Air Purifier 2S is using an EPA filter, while the 2C has a true HEPA filter. However, both claim to get rid of the PM2.5 particles.
Philips Air Purifiers
Philips has a range of air purifiers listed on its website, with three main series: Series 1000, Series 2000 and Series 3000. All of them are equipped with a HEPA filter, and other technology from the company to keep the air in your room clean. The air purifiers start at Rs 12,000 and go up to Rs 30,000 plus, depending on the model you want. The more expensive ones can cover a larger room area and the company has also listed the room size for which it is ideal. For example, the Philips 3000 series air purifier has a coverage area of 1027 square feet. The replacement filters also listed on the company’s website for sale.
Read more: Philips 3000 series Air Purifier review
Honeywell Air Purifiers
Honeywell is another brand that has air purifiers in the market. It also has air purifiers for cars, homes and some which are designed for offices as well. The home air purifiers start at Rs 12,000 and go up to Rs 25,000, though some models are retailing for Rs 7,999 on Amazon India. Some products also come with a live counter to display PM 2.5 levels, and most of their devices have a HEPA filter as well to remove PM2.5 particles.
Dyson’s Air Purifiers
These are the more stylish looking and more expensive range of air purifiers. These start at Rs 25,900 and go up to Rs 54,000 plus in India. The Dyson Pure Cool Advanced Technology claims to remove particles as small as PM 0.1 particles, which most other players in the market cannot do. Dyson claims the glass mesh ensures the smaller particles are filtered even before they reach the HEPA pleats. The Dyson air purifiers have a bladeless fan which adjusts the variable speed of the purifier on its own depending upon the conditions. They also have a display to show the level of pollution in the room.
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