My in-laws have a three car garage, and they let me use the third car side for small engine work. I put this curtain up between the two (about 8' x 9' door) sides. The curtain has been incredibly helpful for both temperature and fumes. If I have to run a machine with the garage open, the curtain keeps the temperature much more consistent on the other side, and keeps the fumes from getting into the main garage and closer to the house. I did a heavy overlap when I put it in, and after almost a year, I have zero complaints.
Shannon 
