side fan blowing in or out?

[jlr616]

OK. Now I'm thoroughly confused. I have always assumed the CPU fan pulls air away from the CPU, and so the side fan directly over the CPU should therefore blow out. But from reading a few different forums, and the fact that some cases come with the fan preinstalled blowing in, maybe my assumption is incorrect. Can someone clarify this issue?

[Telexen]

...CPU fans blow are onto the CPU/heatsink...

I think it's really your choice with a side fan...suposedly they're really useless either way...I'd consider the other case fans, and which way they're blowing...try to make a nice airflow through your case

[woodbutcher]

Most of the heatsinks i've seen latley blow the air down onto the cooler.
For that reason you would want the air to be pulled in thru the side where it is somewhat directed at the heat sink and fan.

WB

[Omardeth]

ya ya what woodbutcher said ...

[ck42866]

Side fan blow in; usually directly over the cpu. Fans on top, out. Fans in front, in. Fans in back, out.

[Bruneau]

Ideally I've found that one should try to follow the natural flow of heat rising. Bringing fresh air in the bottom of the case and venting out the top.

[Telexen]

Originally posted by Bruneau
Ideally I've found that one should try to follow the natural flow of heat rising. Bringing fresh air in the bottom of the case and venting out the top.

Me too...if you go against that you might end up with a certain group of air just staying in the case and defeat the purpose of fans all together

[tony_j15]

Really, it depends on the size of your case, wiring, number of fans, ect.

[MrPurple]

Most CPU/HS fans blow air down onto the heatsink core, but not all. Some do blow air out of the core and into the case.
The side fan for most should blow outside air into the case since its usualy positioned to cool the PIC and AGP cards. This should alos be used by those HS that blow air out since it would cause the outtake rear fans to be less effective.
In my opinion a case should have:
Front fans -->Intakes
Rear fans -->Outtakes
Side Fan -->Intake
Blowhole -->Outtake

The side and blowhole are optional, but I noticed many people using them.

[cruiserlck]

I'm using 2 in the side at the bottom blowing in , a blowhole blowing out , 2 in the front blowing in , and 1 in the top rear blowing out. If I unhook the ones in the side or the blowhole fan I can tell a big difference in temps. I guess in some instances they do help.