How to pollution-proof your house — for a price

The air outside may be noxious, but, for those with the means, there are ways in which homes and offices can be pollution-proofed.

- Vishal Mathur

Air purifiers are the latest appliances that promise to bridge the state's infrastructural and administrative failings - for a price.

Air purifiers have a series of filters including a prefilter for larger particles, a HEPA or high-efficiency particulate arresting filter for smaller and deadlier pollutants, and activated carbon for airborne bacteria and volatile compounds.

They have fans that suck in the air in a room, pass it through multiple filters that capture pollutants, particulate matter and allergens, and then pump back clean air. Most air purifiers can capture airborne particles larger than or equal to 0.3 microns. A micron is the standard unit for measuring the size of air particles.

Each micron is 1/25,400 of an inch or one-millionth of a metre. HEPA filters have ratings, with higherspec H13 and H14 HEPA filters being medical grade, which means they can capture airborne particles as small as 0.2 microns.

Most affordable consumer purifiers have H10 or H12 rated filters. Premium ones operate with an H13 filter. All HEPA filters have a usable life, post which they must be replaced. Depending on their size and filter capacity, air purifiers range in price from 25,000 to 2,00,000.

Some consumers question if these devices will do them any good, considering they still spend enough time outside.