I read so many reviews on this before purchasing and so many said the same thing. That the Philips series 2000 air purifier is life changing for hay fever/allergy sufferers. My 12 year old son has allergies and would often wake at 3am sneezing and congested, unable to get back to sleep or sleep well. He was always waking extremely tired with very puffy eyes and sinuses. Since purchasing this amazing air purifier he has slept through every night, wakes without feeling tired and has not woken once at 3am sneezing. He is sleeping deeper and without any congestion. I, like so many other reviewers believe this air purifier is a life changer. We love it and absolutely recommend it especially if you are a hay fever or allergy sufferer.