I always thought these google photos showing how one was added to a cabinet door was pretty neat. This unit is also vented to the outside.
The propane line feeding the door mounted unit must be flexible I guess... This one is a CAT 5 I think I read...
I don't think I would add one of these inside the trailer unless it was vented to the outside...
I also wonder how much water is generated with one of these. The MR BUDDY Propane heaters puts off a ton of water when being used. I always sit mine in one of those large metal Coleman nonstick griddle trays and dump the water ever so often when being used in my OFF-ROAD POPUP trailer...
Roy Ken