I have been living in an unusually dusty rented cottage for the last few months (I really don't know where it all comes from!) and seemed to have developed an allergy to it, but since recently installing the Mini Max in my bedroom and having it running on the lowest setting through the night (you really cannot hear it, as other reviewers have said, although I have to admit to having been slightly sceptical) I no longer have that blocked up feeling when I wake up and the air feels really fresh. An excellent investment! A word of appreciation too for Lucy in Customer Services, who responded promptly and in great detail to several queries I submitted before finally deciding which model to buy.