Suppose I have a 20x20x20 c"m plastic box where the top cover is open.

On the top cover there is a fan ( 20x20 cm) which suppose to cool a cpu which is in the box .

At the bottom there is a CPU which is getting warm.

Now - in order to cool the CPU - I have 2 options :

  • put the fan to suck air from the box towards outside
  • put the fan to push air from outside towards the box.

Final goal :

Max - Cooling the cpu.


Which is the preferred approach ?

  • 1
    $\begingroup$ Hint: Hold out your palm and blow onto it. Then suck from it. Which one creates more flow? $\endgroup$ – Pranav Hosangadi Apr 27 '14 at 7:25
  • $\begingroup$ @PranavHosangadi I could answer you in this way : when I push the air inside Im actually keeping the worm inside while When I suck the air - I'm getting the worm outside faster .......... BUT I could also the opposite. hence my question. $\endgroup$ – Royi Namir Apr 27 '14 at 7:31
  • $\begingroup$ Try it in a box with one end open, see what happens. $\endgroup$ – Pranav Hosangadi Apr 27 '14 at 7:56
  • $\begingroup$ are you serious I cant test it. that's why i ask it. tnx $\endgroup$ – Royi Namir Apr 27 '14 at 7:58
  • $\begingroup$ Are you serious? This has a really simple answer, and I'm asking you to put your hand in any box which has one end open - not that difficult to improvise - and then blow and then suck air and see which one you think makes more sense to use. As for "keeping the warm in / getting the warm out", it's a better idea to have an inlet and outlet for the airflow. $\endgroup$ – Pranav Hosangadi Apr 27 '14 at 8:00

Browse other questions tagged or ask your own question.