Dyson's latest purifiers combine intelligent sensing with an advanced filtration system. Three phases of purification sit within a fully sealed filtration and airflow system. So what goes inside, stays inside. A solid-state formaldehyde sensor and a unique catalytic filter detect and continuously destroy formaldehyde, an activated carbon filter removes gases and odors and a HEPA filter captures 99.97% of particles 0.3 microns in size. Then powerful Air Multiplier technology purifies, heats the whole room and cools you.