See It There are several benefits to ionic-only air purifiers like the Envion TA500, together with small to no fan noise and no filters to interchange. This air purifier is a true ionic air purifier, and it doesn’t use any regular air filters, like HEPA filters. ORP (Oxidation Reduction Probable) https://rafaeltngwg.post-blogs.com/47964137/facts-about-ionizer-setting-on-fan-revealed