I purchased three lumpiness air units last year around April. I got one for me and the other two for my daughters to have. Anyways, after about two months use my clogged up so bad, I could not use it anymore. So, one of my daughters told me that she had not even opened her and this was in December 2015, so I used it and the exact thing happened to it. My other daughter said she hadn't used her either, so I just opened it and used once. My complaint is this going to be a continuous problem. NOT WORTH THE MONEY FOR SURE!!!