Decks, and my brilliant (?) idea- Radiant Heat!

[Eric von Kleist]

If you wanted to, you could tap in to your hot water line from a propane hot water heater, and just recirculate the water to the incoming line on your hot water tank. A check valve would keep it from flowing back into the holding tank through the cold water input line.

[busone]

Just thinking out loud. If you are not going to need the heat long you could have a big tank of water in or under the bus and heat it hot with the engine coolant while traveling. Then you could circulate that hot water through the radiant system. Of course if you are going to want a warm deck for many hours it would probably cool off to the point where it is worthelss.