New Delhi: It’s that time of the year again when the air quality deteriorates and pollution levels soar, especially in northern India. However, it’s not just the outdoor air that can harm us, indoor air pollution is also very dangerous to our health “as the air is far more concentrated with pollutants than outdoor air and can be up to 10 times worse than outdoor air pollution”, according to Dr Sandeep Nayar, senior consultant and head of department (respiratory medicine) at BLK Super Speciality Hospital, Delhi.
With firecrackers waiting to burst, here’s what to look out for in an air purifiers
In this context, can indoor air purifiers help us breathe good quality air? According to Dr Nayar, air purifiers might filter the air but there is nothing to suggest that using them would actually help in reducing the incidence of health problems. For a typical adult who has to step out of his/her home daily, it will be difficult to assess the importance of indoor air purifiers. Dr Nayar also cautions that some purifiers emit ozone as a by-product, which causes more harm than good.
“Air purifiers control the level of indoor pollution significantly if appropriately used with recommended specifications. An ideal air purifier must have a HEPA (high-efficiency particulate air) filter and should run throughout the day for effective reduction,” corroborates Dr Puneet Khanna, senior consultant and head (interventional pulmonology, respiratory and sleep medicine) at Aakash Healthcare Super Speciality Hospital, New Delhi.
To be sure, Dyson uses a 360-degree HEPA filter in its air purifiers to capture particulate matter as small as 0.1micron, harmful gases and VOC (volatile organic compounds). Its 350-degree oscillation allows it to project clean air in every corner of the room. Honeywell uses three layers of filtration in its air purifiers—pre-filters to remove PM10 and dust, HEPA filter to filter out PM 2.5 and finer dust particles, and the HiSiv filter to filter chemical, VOCs and even bad odour. “We often review filters from Indian homes to understand what pollutants are present,” adds Hugo Wilson, senior design engineer, Dyson.
Besides, users should keep a few things in mind before purchasing an air purifier. First is the coverage area as every air purifier is effective only within a certain range (in sq. ft). Then there is the Clean Air Delivery Rate (CADR), which is a measure of how many cubic feet of air the purifier can filter in 1 minute—higher CADR means better filtration.
Design is also important. An air purifier with a three-dimensional air intake is ideal wherein the impure air is drawn in from the sides and bottom, and clean air is thrown out from the top. Having intake at the back or outlet on the side may lead to the air purifier either taking more time to clean the air or leave some pockets in the room without clean air, points out Sudhir Pillai, general manager, Connected Living Solutions, Honeywell Building Technologies India.
Last, but not the least, running an air purifier for the entire day can be a costly affair and shoots up the power consumption. Also, the filters have to be changed after six or eight months and that means additional cost.