Smart air purifiers adjust fan speed automatically from onboard particulate sensors and report air quality, filter life and run time to your phone.
Match the CADR rating to the room rather than buying on brand. Clean Air Delivery Rate tells you the volume of filtered air per hour; a unit rated well below the room size will run constantly and never catch up, which is the most common reason people conclude a purifier "does nothing".
Filters are the real cost of ownership. A true HEPA filter needs replacing every six to twelve months, and over five years the filters usually cost more than the machine. Check replacement price and availability before buying, and treat washable "permanent" HEPA claims sceptically — washing degrades the filter media.
The automation worth setting up is linking the purifier to a separate air quality monitor, so it responds to the room rather than only to the air immediately around its own intake.
