"Does anyone have a preferred venting method while using a propane heater?"

I have one Kevin. I always crack the top/roof vent an inch, both side
sliding windows an inch, one front window an inch. Allows for some air flow
without losing too much heat. I've adopted use of the thermal blanket
barrier idea, from Richard Jones. The blanket snaps onto the top of the
frame edge just below the van roof line. It's the air duct on the sliding
door side. Snaps along the front edge where the pop top hinge stows when
down, and tucks between the mattress halves at the rear, with the upper bed
folded up/stowed. Anyway the blanket has snaps on it and that traps enough
heat in the cabin to make a 20 degree or so difference between the air above
and inside the cabin. Works well, and still allows the venting to work. Also
use a CO alarm. I've done this a lot so it is safe ... I wake up every
morning.
Bob Stevens
'87 Westy Syncro
"Passion Fruit"