I have a Modine LP heater mounted in the upper corner of my shop:
I will be painting in the dead of winter this year and need to find some way to keep the temperature in the garage up while I'm shooting. I'm wondering if I moved the Modine so that the back side (where it draws it's combustion air) is either sticking into the next room of the garage OR is sticking through the outside wall, if that would be safe enough to prevent the fumes from potentially igniting. My thinking is that this, combined with normal cross ventilation in and out my windows AND my Jet air cleaner, would hopefully prevent the paint fumes from entering the combustion area of the Modine and that I could run it during the painting process.
The other alternative is to jack the heat up prior to the shoot, reduce the cross ventilation of fresh air, and hope I can maintain at least 60-65 degrees in the shop throughout the shoot. BTW, I just ordered a Hobbyair air supply system with full hood so I think I can get away with a little less cross ventilation than might normally be the case. I still need SOME to prevent the "cloud" from depositing too much crap on the car, but health wise, I think I can afford to reduce the flow of air out of the shop.