In the times we live in, pure air is a rare resource and with the onset of the festive season, even more so. The World Health Organization (WHO) has prescribed 25 micro grams per metre cube (ug/m3) as the standard for PM2.5 level in the air. However, several areas in the capital exceed this considerably. Not just the air outside, indoor air, too, is laden with particulate matter that can lead to allergies, coughing, wheezing, chest discomfort and even asthma attacks. Fortunately, you can control the air you breathe at home or in office with air purifiers.
Before buying one though, it's wise to go through a check-list - what fits your room size, the clean air delivery rate (CADR), air changes per hour (ACH) and the type of filter in the purifier, among other things. CADR is affected by room area and height. 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 metres an hour (m3/h) is preferable. Higher the CADR, better the air filtration capacity of the air purifier.
CADR and ACH are terminologies that define the air purifier's functionality. The former shows how much clean air is coming out of the air purifier, the latter determines how quickly it can clean the air in the room in an hour. Ideally, ACH should be four times in an hour - which means an air purifier should clean air every 15 minutes.
The type of filter is yet another important factor - a HEPA (high efficiency particulate air) filter can filter up to 99.9 per cent airborne particles of upto 0.3 microns in size; activated carbon in combination with a HEPA filter can remove odours, too. It's important to note that air purifiers are not one-time investments. The filters need to be replaced once or twice a year, depending upon usage.
Here are some air purifiers you can consider buying:
Xiaomi's Mi Air Purifier 2 is a compact purifier with minimal controls and can be operated through the Mi Home app using the home Wi-Fi network. With a CADR of 310m3/h, it is capable of cleaning 400 sq. ft. area in 10 minutes. It tracks air quality in real time; the reading along with humidity level and temperature is displayed on the app. The app also shows how many days the filter is slated to last. The cylindrical triple-layer filter comprises a primary filter, Toray H11 grade HEPA filter and activated carbon to remove dust, odours and other harmful particles. This air purifier is retailing for Rs9,999. With a new filter costing only Rs2499, this is not an expensive buy.
Universal 450 from Atlanta Healthcare comes with a built-in humidifier along with an air quality sensor and filter change indicator. The filter keeps indoor air free from dust (PM2.5 and PM10), gases, smoke, odours, allergens and airborne infections. Its 'seven-stage' air purification process includes pre-filter, anti-bacterial filter, H13 grade HEPA filter, activated carbon, photo catalyst, UV light and ionizer. It has a CADR of 225m3/h. This air purifier is currently retailing at a discounted price of Rs21,560, and the filter is easily available on Amazon India for Rs3,000.
After launching high-end air purifiers last year, Honeywell has introduced mid-segment air purifiers - Air Touch I8 and A5 - featuring a three-layer filter that eliminates large dust particles, bacteria, formaldehyde and volatile organic compounds. It claims to offer PM2.5 removal efficiency of more than 90 per cent. Honeywell Air Touch range of air purifiers come with a three-stage filtration process - the company's HiSiv filter, HEPA filter and a washable pre-filter. Both the Air Touch I8 and A5 feature a touch panel with controls and indicators; they do not come with a remote or mobile app. This means one has to go the purifier to operate it. This new range is priced in the range of Rs11,490 and Rs22,990. The cost of replacing the filter could be between Rs2,500 and Rs6,000.
Philips 2000 Series AeraSense (Rs15,999) and Kent Aura 45-watt (Rs10,999) are some of the other popular air purifiers in the market. Air purifiers from Blueair and its new Classic range of air purifiers (available from Rs55,000) are also worth considering.