C3H8 + (5)O2 --> (3)CO2 + (4)H2O that is, propane plus oxygen yields carbon dioxide, water and heat. that being said, a few moments of interweb research and it looks like RV propane units do vent...

hey mt mike,
heater wise, ever consider a small wood stove? propane is such a damp heat on long winter camper stays nothing dries out. they make some cool wood stoves for boats ($$$), i'm sure...