After installing a vented propane heater in my '77 Camper, Idecided to 
put it to the test: 2 weeks of snowboarding and backcountry skiing in 
Utah, Idaho and Montana. 

The heater (Force 10, 5000 BTU obtained from West Marine) worked fairly
well under normal conditions, but gave me problems when I needed it most. 
The heater is outfitted with an oxygen depletion device that turns off the
unit when oxygen levels "drop to 95% of normal conditions". At 9000 ft.
above sea level and -15 degrees F. (Galena Pass near Sun Valley, Idaho),
the heater would turn itself off. I had installed ventilation fans in the
rear vents that originally were menat for heater ducts, but they weren't
sufficient under these conditions. Brrrrrr. The most aggravating result of
winter camping was the interior condensation on the windows. 1-2 mm of 
ice on the interior every morning!!!!

Conclusion: If you want serious heat while parked, get a Suburban furnace 
(Camping World ~$500) and make sure you have a well charged 2nd battery.
My heater is a good low tech alternative if you're going to be away from 
civilization. (~$300, no battery draw). The easisest and most effective 
alternative is to stay at an RV Park and run an electric heater. ($30, 
plus $15/night), but this won't work on cold evenings at a trailhead...

Note on heater safety: my CO detector triggered 3-4 times; always due to 
idling of the engine in the morning....(don't sleep in your car with the 
engine running :)

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     Morris Arthur < morris_arthur@unc.edu >
     Environmental Sciences and Engineering
     University of North Carolina
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