“The Dysons we tested averaged a CADR of about 140 m3/hour, lower than most of the other air purifiers we tested, and well below the approximately 200 m3/hr Siegel recommends for cleaning small to medium-sized rooms.”
Dyson charges $800 for a purifier that lost to a box fan with a filter strapped to it. The premium buys a sleek shape and a heater. Moving lots of air through a filter is the whole job. A homemade fan did that job better.