_{¹The standard purification and heating performance tests are AHAM AC1-2015 and IEC 60675 respectively. Dyson goes beyond these, by testing filtration efficiency at 0.1 microns (EN1822), air projection (DTM801), purification coverage in a 81m3 room with multiple sensors (TM-003711) and heating performance in a 35m3 room with multiple sensors (DTM 961).}