->  TW>  By design very little power supply heat is radiated inside the
->  TW> case. In fact the way the Fans operate they actualy pull Cool air 
->  TW> into
->  TW> the Case helping with overall cooling. 

-> All the power supply fans here blow air out of the power supply, and there are
-> no other fans in the cases.

 That is Correct. And that means that IF warm air is being blown out
form the Power Supply it Must come in somewhare. Typicaly from an
opening on the Front of the case drawing that Cooler Outside air over
the MB and Cards keeping them cool before being drawn into the Power
Supply cooling it.                            
Some cases have a spot for a Fan on the Front air port. A Fan here
blowing in is a wise move in thew warmer climates if one dosen't have an
Air Conditioned Computer Room. 
 To make this all effective one should keep the sides ON the case and if
there is any openings on the rear of the case for additional fans they
should either fitted with fans to blocked off if there is no pusher fan
on the front. .
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