Need an opinion on direction of air flow.

Ok folks, I need your opinion on this one. I'm thinking of creating an air duct in my computer for the new processor fan I'm getting (used to have my system liquid cooled but the water pump is on it's way out and is getting VERY loud). It will connect to the existing case fan on the back of the case. The fans will both blow in the same direction... either in or out.

Now my question is this, which way do you think would cool the processor better?

Blowing air in the system and onto the processor thus cycling more air in the computer?

or...

Sucking the hot air off the processor and blowing it outside the case?

:confused:

Well, since it is opinion you asked for, heres mine: sucking cold air into the case and blowing it directly on the processor will cool far better than sucking the already warmed interior case air through and cooling the processor that way. It helps also to have an appropriate psu with either the air intake or the fan sitting directly above the processor

Blowing cools the heatsink more efficiently in my opinoin.
Perhaps you should have posted a poll :D

Blowing air in over the CPU HSF is a good idea to cool it further but you may cause other components to not have air flow over them.As back in the day, best to suck air in front and out back. I have a double fan PSU sucking directly over the CPU fan that wisks away the hot air. Same thing goes for the rear fan, it sucks out. If it is not set up this way the air will come in the back and flow out the back in a cycle that just moves warm air over the CPU and MOBO. The HDD's and other items in the front do not have air pulled over them and get hotter.


I have low flow fans coming into the PC in the front to move air over HDD's to cool them. This is known to increase their life expectancy. I also use multiple blowholes. One on the side blowing in at the vid card/CPU and one on top venting out.

I use vantec stealth fans or cheapo 80mm fans I have placed a resistor on to limit the RPM to 1200-1500. This makes the 4 fans I have all very, very quiet and a Thermaltake silent PSU is great too. Some Dynamat sucks up the HDD niose and the loudest thing on the machine is the P4 cooling fan.

I have a high powered Aero-Cool fan blowing air onto my processor (P4 2.8GHz hp/800fsb). Then I have 2 fans facing opposite blowing the air out of the case. The end result is air pushing the heat away from the processor, then the case fans pushing it out of the case. The air travel ends up moving in a sort of U-shape. Then of course I have the fan on the power supply. There are many opinions and there has been much research done on this. But I can tell you from my experience that my processor was running at around 31c, and since I did the fans this way, it's now running at around a very cool 22c.


It kinda ends up like this (arrows indicate air-flow)

[CPU] - [HS] - <--- [1 Fan blowing onto cpu]
[Case] ---> [2 fans pulling air out of case]