Quote Originally Posted by Rusty Trichome
I'm with IR on this one. Plus, plastic sheeting can trap moisture between it and the wall. (mold)

Why not a white sheet hung with some push-pins? Does cotton-fiber white reflect less than wood-fiber white, or any more than cotton-polyester white? Is the difference worth worrying about?
if there is a possibility that water is getting on the wall, it's going to mold with or without plastic. Control the humidity and overspray or u definitely will end up with a mold issue.

And emergency blankets trap a lot unwanted of heat/humidity especially in small grow areas.

& as far as the smell, if you can, the best way is to use a blower and vent it out of the top of the wall, to the outside, or more preferably, an exhaust fan thru the roof. High enough so nobody walking by can pin-point where the smell originates. Remember, heat rises, and with it, the smell. So pull the hot, moist air from the top out and let fresh, cool, dry air in from the bottom.