I bought this one year ago. It is still humming along and creating very clean air and perfect amount of white noise to help me sleep in as I live in a very noisy urban area with tons of dirt dust and pollution. While considering a second purchase for another room, I looked up the EPA INFO ON INDOOR AIR FILTRATION SYSTEMS. This one is a winner as well as Honeywell models:HPA204C; HPA250B; 50250-S; 5025 -N; 50255-B; warning you must be careful when buying others and should investigate before purchase as higher (over 350) CADR numbers might indicate high levels of ozone output which is a known lung irritant. According to the EPA WEBSITE ... All Honeywell models are SAFE! Also pre-filters are very inexpensive as you get enough to replace several times in one box and you cut to fit so you can also use those filters in your forced air vents if living in apt complex.
If you need further help or information please visit our Online Help Center