L330 - Fogging up of Room when using Scrim Banner

Hi All, This is a first for me. I hope someone has some insight into this. The client called me and said that his print shop (small store front type) fogs up when the HP DJ L330 is running, printing on Scrim Banner. He's had the unit for about a month - I think this is the 1st long run. . 4ft x 20ft banner and they had to open the door to help cleaer the air No Odor, No burning smell, no smoke - just windows and air fogging up. We believe that the temp. might be too high and there is some media coating burn off. NOT sure??? Has anyone else seen this? Roy K