HD cooling question

[corwin]

This may seem like a strange question (or maybe just an easy one) but which side of a hard drive radiates the most heat? I have 4 drives in 2 cages and was thinking of flipping the bottom one upside down to create more of a gap between them with a fan in front. Just wondering if it would be more effective with the tops facing each other or the bottoms....Thanks for the help I am sure you will provide!

 

[imported_redlotus]

I'm not 100% on this, but IIRC the PCB side is the one that you have to worry about.

-red