India, Nov. 15 -- This November, early mornings in Gurugram's high-rises look like a war scene straight out of a Hollywood movie. Wondering how? Picture rooftop anti-smog guns spraying fine mist as residents of skyscrapers head out for their walks. Kilometres away in Greater Noida, security guards hose down internal avenues before school buses roll in, while Faridabad societies run automated boundary sprinklers on hourly timers. High-rise living in NCR has acquired a new winter amenity: DIY clean-air engineering.

With indoor purifiers running round-the-clock inside apartments, Resident Welfare Associations (RWAs) across NCR are investing in outdoor air-scrubbing setups turning lawns, decks, and terraces into dust-suppression zones. For r...