So I've discovered that I can get my PSU, RAMPS and Pi 2 all in roughly a 240 x 120 area.
I also found some nice blue LED lit 120mm fans. 2 of those could be mounted directly above the components and cool the entire thing.
Now a friend and advisor of mine said that's ridiculous, use 2 50mm radial fans instead... he had me convinced for a while even though the design of the fans isn't the most efficient (they're forward sloping blades).
Then I saw the CFM difference (CFM = cubic foot per metre and is a measure of volume flow rate).
Here's the breakdown:
120mm fan - direct axial style.
-18-20DB (whisper quiet)
-outputs 32 CFM
-draws ~0.2A
50mm centrifugal/radial fan.
-DB unknown, probs more
-outputs 3 CFM
-draws ~0.2A
The main caveat of the direct fans is that still air beneath them slows them down somewhat, radial fans cope better.
The thing is, with a PSU, RAMPS and Pi all in one small area I want to get the best (and quietest) cooling I can. Obviously I'd cover the 120mm fans with fine mesh to avoid damage.
I really respect my friend's opinion, he's had many years more experience than me and for the most part I trust his judgement, however in this case I feel he could be wrong, the airflow is an order of magnitude greater with the 120mm fans.
Your advice, thoughts and suggestions are greatly appreciated, thanks!