Theory of cooling goes something like this:
* Fan work better when blowing cooler air, it's denser.
* To get maximum efficiency, the warm and the cool go in the opposite directions. Like 2 water pipes soldered together, warm water flows in one direction through one pipe, the cool water flows in the opposite direction through the other pipe. This is the principle that most heat exchangers work on.
* To get maximum cooling, the coolest part should contact the warmest part directly.