The Dyson Purifier Big+Quiet Formaldehyde is our biggest purifier yet, engineered from the ground up, to evenly purify large spaces. Cone aerodynamics creates a condensed jet of air to project purified air over 32 feet. Quietly. An advanced 360 Hepa H13 grade filter captures allergens and 99.97% of fine particles. Removes gases and odors.² Destroys formaldehyde, permanently.