Originally Posted by Daniel V.
I have been on a similar quest for a while myself, and came across this one recently...
Not sure about availability and haven't read about any RV install yet, but perhaps worth inquiring about.
There are quite a few direct vent propane
furnaces on the market. I have had one in a house before. The issue is how you will vent them as the vents they use are created for passing through the thick walls of a home versus the thin walls of a fiberglass trailer. Many of them vent through the roof rather than walls. However the exterior vents that fit them are not made for use in a vehicle in motion. So no matter the maker of them you have to figure out how you will adapt them as far as the venting.
The Marine propane
heaters do have vent stacks that are made to go through the roof and they are going to have a smaller diameter chimney stack as well as a cap made for travel. They already have the right types of exterior vents including ones for sloped or curved roofs. They are made to be used in fiberglass boats so you know the flue temperature will not be an issue for safe installation in a fiberglass trailer. But you do have to follow carefully the instructions for clearances from adjacent surfaces not just beside and below but also above.