The Dyson Purifier Cool Gen1 purifying fan automatically senses, captures and traps pollutants to purify your whole room¹, while removing 99.97% of particles as small as 0.3 microns.²¹Tested per Dyson internal test standards for whole-room air projection (Tm-005021) and purification coverage (Tm-003711)²Tested per Iso 29463.³Fan, not an air conditioning unit.