We have used a 6000 BTU unit in our rig for the last several years. It will not heat the whole unit up - it puts out about the same amount of heat as a 1500 watt electric heater. We do a lot of boondocking and this is the only heat we use untill the weather gets down near freezing. I have it on a quick disconnect with a six foot hose so we can aim it where the heat is needed, as in the bathroom for taking a shower
It should work very well in your camper.
The heater doesn't produce CO, but does use oxygen, so a window or vent should be cracked open. Propane does give off water vapor when burned, but we have never noticed a problem with it. Does not give off an oder when burning.
For more info check www.uscatalytic.com
Hope this helps,
'97 Bounder, 32H, Chevy 454; ipd, Bilsteins, Air Lift, Banks, Hendersons, Solar.