also, I think you might wanna take that cap out of the exhaust on your vacuum pump, no? or its probably vented. I try to vent mine outside, or at least put a rag or towel over it so its not as loud, and captures some of the fumes and turns the rag oily... wouldnt wanna be breathing in tons of that stuff just to be safe if its making the rag oily
not only is it moisture, but its butane from the oil, and fumes from the vacuum pump oil
change the oil every so often, ESPECIALLY if youre cooking off ISO and everclear in that chamber. (you can cook off liquids at a lower temp in there... water normally boils at 212F..it boils at 20F at 29.75" vacuum.)