positive vs. negative airflow

[revanrules]

Which is better? I've heard good things about both such as positive makes your case less dusty and negative keeps it cooler, but are there any write-ups or tests that people have done which i can read in order to make a better decision? what do you guys think?

 

[Gneisenau]

This article makes as much sense as anything I've read. http://www.maximumpc.com/artic...ich_way_should_it_blow
It kind of mentions pos -vs- neg pressure, but the bottom line is what works best with one build may not work best with another build.

 

[Bluefront]

The problem is that almost no cases are designed to be positive pressure. So if you want the benefits of this setup, you'll have to make your own, or modify an existing case. For a beginner, this may be difficult.

I've gone 100% positive on my last six computers......and I can say with certainty, I'll never build a negative pressure case again. My computers now run super clean, since the intakes are all filtered with good air filters. I have no dust entering the ports, or the optical drives. The CPUs run cooler since ambient temp air is being blown directly on them. I use fanless power supplies and no exhaust fans. The setups are quieter on positive pressure also.

Example link....

 

[Zepper]

Yup, to get positive pressure w/o a massive (or very noisy) intake fan (s), you have to plug up any major superfluous exits for air. Then you have to have enough intake fan to overcome the exhaust fan(s) plus whatever leakage remains. Cases like the XClio Windtunnel with the dual 250mm fans can be positive pressure right out of the box...

.bh.

 

[Modelworks]

Positive is great for dirty environments.
Its also what my former workplace, cray research uses for air based cooling.

Even though I have worked with it , I don't use it at home.
I use two large 120mm fan, with about 75cfm on the intake and exhaust, with my psu ducted so the intake is from outside the case.