Yeah, Im think of punching it halfway down and on the opposite wall, where the diagram shows "New Exit". That way I have 2 exits, one midway and one higher up to experiment with. I guess I'll have to find out through trial and error which exit will work best for the Cooltube exit and which one will work best for ambient temps exhaust?

Will I need another similiarly sized fan for the ambient temps exhaust? Cos they're pretty loud and expensive...

About its capacity...any stronger than that and my coats hanging in the hall where it exits will start flapping. Theres a lot of air being pumped out...