According to EODY "the recycling of air without ensuring its continuous cleaning with HEPA filters should be completely avoided, especially in aerosol production areas."
The CADR value is the rating of the air purifier's ability to deliver air pollutant-free to the space, expressed in cubic feet per minute. The certification is done by special independent laboratories.
The HEPA (High Efficiency Particle Arresting) filter is made of tiny glass fibers, which have been turned into a densely woven paper. This creates a filter consisting of a multitude of very small "sieves" that can capture extremely small particles.
The Kullhaus HEPA 13 (High Efficiency Particle Arresting) filter includes 4 air filtration/purification technologies. Pre-Filter, Nanosilver, HEPA Type 13 Filter [True HEPA] and Activated Carbon Filter.