India, Nov. 28 -- Right now, in winter, many homes are stuck between bad air outside and stale air indoors. Windows stay shut because the AQI is high, yet by evening a fine layer of dust still settles on the sofa. Light upholstery looks dull within days, and even with an air purifier running, the couch quietly picks up what the machine misses.

At the same time, the sofa has become the busiest spot in the house. Pets climb over it after a walk, kids eat chips during cartoons, adults sit there in clothes straight from smoggy commutes. A quick pat sends up dust, hair and crumbs, and that mix starts to bother noses, skin and allergies. A cloth wipe is no longer enough, and this is where the best vacuum cleaners for the sofa become the most s...