HeatSink airflow question/idea....

[G T i]

First off, I would like to ask a really simple question. What is better for a CPU heatsink? A fan blowing at it or a fan sucking air from it? Second is, does this fan need to be right now top of the heatsink?

OK here is what I am gettin at. What if I were to install a SK6 (no fan), mod my case with a 90+cfm 120mm fan blowing air right into the heatsink unit? And having fans sucking air from the top of my case where the heat from this heatsink (blowen off the heatsink by this 120mm fan) away.

I just thought of this idea and wonder if anyone else thinks this would or wouldn't work. Of coz I will lap the heatsink also.

[FerrariF50]

You must be talking about a Socket 370 ummmm I would think air blowing on the heatsink would be better because if you had the air sucking away. The metal fins on the heatsink would cause alot of flow destursion.

[G T i]

Has anyone tried to do this yet? Well, I think I am going to try this out anyways. And I'll also plan to use the delta fan on the heatsink too and see if the 120mm fan really helps.

[Bobby Manus]

Yes its been done... The Hoot Chut as people are calling it, he hooked up a massive fan and then made a card board duct that directed the airflow direcly on to the heatsink. I would not recomend what you are thinking though, as a 120mm fan doesnt blow air straight, it blows the air in a spiral motion and it goes out at an angle. Hoot used a completly different type of fan, that blow air straight and it was extreamly powerful, not at all intended to be a case fan :D

[cjtune]

Doesn't really matter, as the heatsink fins present an obstruction to the fan whether it is sucking or blowing, hence the flow rate will be the same. With sucking you gotta use shrouds/skirts to channel the air being sucked as it doesn't travel as straight a path as air being blown. Take care not to constrict the intake area for the fan when using skirts.

[Bobby Manus]

O btw personal expierment proved for me to have temps almost 5c lower avg when my fan was sucking. This is with a svc goldengate 38, which is basically an ocz gladiator with a delta. In my opinion sucking will almost always work beter, heatsink apear to be designed to have the heat go up and out, just get the heat away from the processor as fast as you can. Although blowing is also good becuase you are cooling the cooper plate and fins that are touching the core, so I supose you should just see what works best with your setup.