--- On Fri, 12/12/08, Richard Faesy <[log in to unmask]> wrote:
An unvented space heater like a salamander dumps all of it's products of
combustion into the space in which it is located.  This results in approximately
1 gallon of water vapor produced for every gallon of propane or kerosene burned,
assuming complete combustion 
Years ago, I was working on some modular condominiums being erected at Mt. Snow. Each unit had a large propane construction heater in the basement. I had to go up through the attic hatch for some reason in one of the units and - to my surprise - it was snowing in the attic!