I bought this for my wife and was unsure this will work or not. But thought should give ago. Yes , this works. First day i kept this inside our bed room and the door was closed. Next day morning she wake up without any block nose and without sneezing - hey fever symptoms. She said this is the first day woke up well after the spring starts. After that we moved it to the living area which is much bigger in size. Yes it works well. But it works bit longer time to get to the lowest fan speed which is accepted. Wish we bought this early spring where the hey fever starts. Even though its bit expensive, worth money as you dont suffer with hey fever while inside your home.