I have three of these units and I have to say that they are very good quality. These units are very well built with heavy duty components that are able to process a rather large volume of air. The unit is relatively quiet, even on the highest fan setting. It is much quieter than a box fan. My wife and I are able to sleep just fine with the unit next to the bed. Filters last a good while, I have been getting 10-12 months out of them. To help kill virus particles that I am sure get trapped and some pass through, I have started to spray the filter with a disinfecting solution as well.