Forget unvented catalytic heaters, except when you leave the
sliding door open.
 Otherwise I wouldn't have an unvented heater going inside a westy.
The code does not permit permanent installation of
unvented catalytic heaters in homes etc., because they are not safe
without adequate draft/ventilation.

My favorite is the Plat Cat vented catalytic heater.
See my webpage:
ttp://www.geocities.com/harald_nancy/plat_cat_heater.htm

That heater keeps running for weeks on one aux. battery charge.
The 2.6 gallons propane are enough for several days of use.
While running, it constantly recirculates fresh air into the camper
through the front vents, and pushes out the exhaust air/condensation.
It keeps the westy warm and dry, even in humid climates.
The webasto/propex don't draw in fresh air, since they recycle the air.
Since the plat cat is radiant, the poor insulation of the westy does not
matter so much, since it's always warm in front of the heater.

See Arnie Lind's website for ordering info:
http://www.omnicast.net/arnie/

If enough vanagon owners call or email him with orders,
maybe he'll make another production run.

I'd like to buy another one myself for my workshop.

Harald
'90 westy