AAHHHHH.....breathing without wheezing again ! LOL ... I'm one of the dust allergy sufferers ( Ugh ! ) and I just had my original 1950 gravity fed house heater replaced two days ago (Yay!). Needless to say, the 1950's dust was blown through my home and within on day of replacing the complimentary fiberglass filter (useless) with a 1900 Filtrete filter, there was a remarkable difference overnight! Looking forward to testing out the 2200 filter. THANK YOU Filtrete for making such an efficient filter !! :-D