Review on 🔍 Fette Filter 2-Pack of High-Quality HEPA Filters with 8 Carbon Replacement Filters – Compatible with Winix Filter A 115115, Size 21 – Plasma Wave Air Purifier 5300, 6300, 5300-2, 6300-2, P300, C535, AM90 by Adam Webbie

These are very good filters, they only last about a month and a half as activated carbon filters. The filter should last up to a year (they say it doesn't need to be cleaned) but I've already cleaned it once with the kitchen countertop thinner I use (Dawn's Potent Pot and Pan Spray) and the filter was cleaned very well. Well that was it in the summer months and I just left the filter out in the air overnight to dry. I'm sure you could put it on a heater in the basement to dry in the winter months, or if you have a radiant heater you can put it on the radiator overnight.