We bought this air conditioner last summer to cool the upstairs bedrooms in our house. It worked great for a year. I had no problems with its' performance. 
Last week, it started blowing what looked like fog out the back of the unit. I turned it off and the fog continued to flow out of it. I made sure the filters were clean, which they were, and plugged it back in. It will blow air but the compressor does not kick in now. I called the customer service number listed in the manual many, many times the last 5 days. I have left numerous messages but have not received a call back even though the message says they will return my call by the next business day. There is a website given to look at for portable air conditioner problems, but my problem is not listed on the website. I need to talk to someone!
If this unit had kept working like it did a year ago, I would have given it 5 stars. BUT - I think something you pay hundreds of dollars for should last more than a year.