Fan position for CPU heat sink

[Colonel Panic]

I need to put an aftermarket 3" PC fan on an old Dell and was wondering if I should make the fan blow on the heat sink or flip it to suck heat away from it. It's an old POS and I can cut holes in the tower if I need to.

Any thoughts would be appreciated.

Thanks

 

[Amr Rahmy]

pc fans are made to suck the heat away from the machine.

so if your putting the fan on the same side as your motherboard connections(usb, gfx card, ethernet, vga or dvi, sound card connections) it should suck the hot air from inside to the outside.

if you have more than one fan you could put one parallel to the other and same direction, at the other end(closer to the harddrives and cd/dvd rom dirives),so it would work as a fan, sending the air inside the machine to the other fan.