CHENNAI: With rising pollution levels, the time is not far off when an air purifier becomes an essential home appliance. And a team of researchers at IIT-Madras are ready with an affordable one.
The team has developed a sensor-based indoor air purifier that promises to reduce the pollutant load including microbes in the air. Some companies have been marketing air purifiers that cost Rs15,000 upwards for a small room. Made out of commonly available low-cost materials like activated charcoal and ultra-violet light, the product from the IIT stable promises an affordable alternative.
Chennai, which has an air quality index of around 55, is among the ‘good’ cities in terms of pollution; Delhi, with an index of 313, falls under the ‘very poor’ category.
Air OK Technologies, a faculty startup launched under the IITM incubation cell will soon commercialise the device. Among the first domestic buyers could be people with asthma and such respiratory diseases. It is also designed to fit in any place that needs a sterilised environment such as a hospital or highly polluted areas like basement parking lots, buildings facing roads and dusty localities.
The purifier works on a simple three-layer technology similar to that of a water purifier. A fan fitted at the bottom of a stainless steel cylindrical body sucks in the air after a sensor detects pollutants in the air. The air is transferred to a bag made of muslin fabric that acts as a pre-filter and removes large particles like dust.
The second layer of filter is the activated charcoal produced by burning wood. The bag filled with a thick layer of charcoal in the bottom and to its sides absorbs the pollutants including chemicals and other microscopic particles. Researchers say substances in the air get stuck to the pores of the charcoal. “The high surface area of the charcoal gives it lot of bonding places. So, the better the pores, the better the adsorption capacity,” a research team member said.
With a reduced level of pollutants, the air passes through the third filter. The filter has a ultraviolet light fixed above the activated charcoal layer that treats bacteria and viruses. The treated air is then let out. The system consumes 50 watts.
Associate professor at the Environmental and Water Resources Engineering S M Shiva Nagendra said that air quality in rooms requires attention as much as the outdoor environment. “We spend a lot of time indoors. While pollutants outdoors move around, in rooms they get accumulated and keep circulating,” he said.
Source: Times of India
