Rainbow is not supported by ANY asthma or breathing problem organization-nor do they post any inofrmation on the so called effectiveness of their product-Filter Queen states their effectivness as well as the endorsement from the AAN.AM(Allegey and Asthma Network/Mother of Asthmatics)I used to sell them and they stop snoring- prevent fleas, are used in Hatcheries to purify the air as to keep birds disease free and give them a better chance at life, not to mention the air opurification on the home- I have had many people that bought one that had breathing problems-some fatal... say how much it helped them just by running it one hour a day to filter the air--And the cleaning abilities of this machine is UNMATCHED.......We demostarted the suction power and always won against Kirby and Rainbow.... ALWAYS.. I used mine for construction clean up also---The sludge at the bottom of Rainbow is MUD and stinks it not changed everytime.. No Comparison... FILTER QUEEN all the WAY!!!