Well, if you are talking about the small fan closest to the center of the notebook, I think mine sucks in, not out. If it is blowing out, it is VERY faint, not even enough to move a piece of paper. The largest fan I can feel suck the air in.
How hard does yours blow out?
I thought all fans on the botton of the 8790 sucked in. Try and get some more input from others on this topic to find out if what you were told is correct. I am not sure it was.