I love my EVAPOLAR EvaChill Air cooler; I use it in my office to keep me cooled. Too many electronics inside my office and my doors have to remain closed because I talk on phone too loudly. The USB power really is a wonderful feature since I have an overabundance of USB charging ports available already. I recently changed the filter for the first time, and the experience made me happy about my purchase once again. The ease of changing the filter blew me away! I shut down the cooler for the winter months, and when I was ready to start up, the new filter dropped in, and I was up and running so quickly I was amazed!