Cooling Direction

[Cygnus-X1]

Is it best to have the air blow out of the rear, or in from the rear?
My power supply seems to blow air out of the rear so the extra fan I have is set up the same way.
Do most power supplies blow air into the case or out of the case?
Just curious.

[NDC]

In my opinion, it's best to have the fans mounted at the back of the case to blow out of the case, since heat rises, and it would be best to have air flow in from the front of the case since it's positioned at the bottom of the case.

[sns]

The few I have had (& the ones at work) blow the air out of the back (Or in other words suck the air out of the case).
The Aopen desktop I now have (& last one I will have) has a row of holes on one side so the air (& fine dust etc) gets dragged across all the cards, ram, h/drives and lastly the cpu then out thru the pwr supply.
My old miditower never got as dirty but it didnt have as much air flow either so its a bit of a trade off.