The Dyson Purifier Hot+Cool Gen1 purifying fan automatically senses, captures and traps pollutants to purify your whole room. It heats or cools the air, while removing 99.97% of particles as small as 0.3 microns. Tested In maximum setting for air projection, tested in Auto mode for purification coverage, tested for room heating per relevant Dyson method DTM961.²Fan not air conditioning unit Tested per Iso 29463..