I put my case close to the window, and started up my fan contraption (no tubing yet though) and it blew.. generally cold, not too cold though, maybe like 5F degrees into the fans in the back, and it dropped my cpu temp from 97 to 49, 48degrees, thats pretty good. This is immediately after I applied new thermal compound and cleaned out my heatsink which was gettin clogged with dust, I left it (the fan) going for a few hours but it was gettin cold in my room. I thought 48 degrees was pretty good, and case was closed and no fogginess or anything. I think its ok.