My air conditoner drains directly on the roof of my trailer and runs toward a side mounted drain gutter which routes the water to one end of the trailer or the other. I always angle my trailer abit toward the back when I setup to make the water flow to the back of the trailer.
This is pictorial of the roof mounted air conditioner. Note the 14" x 14" foam gasket sandwiched between the air conditioner housing and the trailer roof. This gasket is what keeps the roof water from coming inside your trailer. This gasket should be depressed about a 1/4-inch by tightening four long bolts from the bottom side of the air conditioner mount accessible from the inside unit.
I have seen some folks apply some dicor on the roof to make a dam of some sort to direct the water flow of the air conditioner directly to the side drain gutters. They also apply some dicor on the rear of the roof to keep water from running down from the roof onto the rear big picture windows.
just my thoughs
Roy Ken
