"The Dyson Pure Cool purifying fan, DP04. The only purifying fan to clean a whole room properly. We design our purifying fans to go beyond test chamber conditions and focus on real home conditions - this is more than just having an efficient filter.1 Dyson engineers and research concluded that to clean an entire room properly, you need to sense pollution events automatically; capture ultrafine pollutants; and project cleaner air around the room using Air Multiplier technology. Only the Dyson purifying fan is designed and tested to do all of this.2 1The AHAM AC1-2015 standard sets out how air cleaner manufacturers can define their performance by ""the relative reduction of particulate matter suspended in the air in a specified test chamber"" - this means their performance is based on cleaning efficiency rates only. 2Tested to Dyson internal test method TM-003711 in a 290ft2 room and DTM801. Color: White."