any hydrocarbon (propane being one) will produce water vapor and carbon dioxide when fully combusted.

C3H8 (propane) + O2 -> CO2 + H2O (not balanced)

if not fully combusted, you will get CO produced.

you will want good air circulation if burning fuel in an enclosed space. even if you didn't have any carbon monoxide produced due to incomplete combustion, you'd use up your oxygen which isn't good either.