If I could give this 10 stars I would.  I have asthma, 2 guinea pigs, 2 dogs and a cat, I have had my share of air purifiers in my lifetime, even the really expensive ones that start with a D and end with a N, and lemme tell you this machine has been telling me I have bad clean air for a few hours as it did its thing, mind you, the room I put it in has a winix and a Dyson in it, I immediately can tell a difference in the air. I am a believer!