I’m assembling my new system, and I got an extra fan for the case. My question is, do I install it so the fins look the same as the back fan, or do I install it in reverse so that one fan pushes air in and the other fan pulls air out?
Fans should be installed so they blow outwards. A fan blowing inwards sets up air currents in which eddies can develop, thereby creating hot spots. Pushing the air out of the case sets up a more even flow of air that cools the innards more uniformly.
It depends on the number of fans and location. If you’ve only one fan, it should probably exhaust hot air out of the case. The power supply will be drawing outside air into the case already.
If you’ve two fans, front/side and back, the front/side should intake and the rear exhaust.
Be sure to properly cool your processor with a dedicated heat sink/fan (you probably already know that, but better safe than sorry).
I see Q.E.D. and I disagree slightly (I say front fans should intake, he says (all?) fans should exhaust). I offer up the following cite/site:
http://firingsquad.gamers.com/guides/cooling/page2.asp
OK, the fan I have is in the back. I’m assuming it is set up for exhaust. The fan I have is going in the front. This means the front fan should be an intake? BTW, I have a little plastic bracket that the fan in supposed to mount in, should I try to get the front off and screw the fan to the case, or just rely on the bracket?
You have it correct; front fan intake, rear fan exhaust. Use the bracket; these should all be of standard size.
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- The fan should just snap into the plastic bracket, if you got a half-decent brand of PC case…
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- If you have one fan, you can use it intake/front or exhaust/rear, there’s not much difference except that it’s a bit quieter if you mount it exhausting out the rear of the case.
- If you got two case fans, you mount one in the front pulling air in, and the other in the rear of the case blowing air out. The reason is that if one fan should stop working, the other will continue to circulate air completely through the case (at a lower rate, but still, and this is assuming that you have blocked off all the empty fan mounts with something). If you had put both fans in the rear blowing out and one fan stopped working, the other would pull air in through the dead fan and right back out through the still-functioning fan, not cooling anything inside.
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Case fans shouldn’t be used to direct air to any particular areas. They are meant to exchange the air in the case with outside air as fast as possible, thus keeping the ambient temperature inside the case as low as possible. Using them to cool components compromised their efficiency in this regard. The CPU, videocard, and motherboard chipsets all have their own cooling systems, and the best way to improve their efficiency is to keep the ambient case temperature as low as possible. Hard Drives simply aren’t significant heat sources, the best way to cool them is also to keep ambient temperature low.
In general, you want fans in the front of the case to blow in, those in back to blow out. Ideally your case will be at positive pressure (more intake than exhaust) but as long as pressure isn’t dramatically negative, you’re fine. Fans near eachother should always blow in the same direction, and component cooling fans almost always blow down onto the component being cooled, not suck away.