My chronic allergies and sinusitis have required that I use HEPA air filters in every room of my home. Over the past 20 years I have owned many different units, almost all of them were manufactured by Honeywell. While all had the same basic functions and worked quite well, this unit is by far the best and quietest air filter that I have ever owned. Consumer Reports rates this air filter very high and with good reason, because it's the best and most affordable uni..