extra fan on the side of the case: blow in or out??

[VTBigBear]

I am thinking of putting an extra fan on the side of my case.
should i make the fan blow in or out?
i have one fan in the front taking in air and two blowing it out in the back.

thanks for the tips in advance.

 

[BeHeMOTH]

I was think the same thing, I was thinking of a 120mm fan blowing in I have 2 in the rear blowing out?

 

[mechBgon]

I vote for "in" after trying both ways on my systems.

 

[VTBigBear]

so you think that there should be a fan blowing in ?

so where do you guys think this fan should be blowing on??
the cpu or on the video card??

i personally think that it might be better to have the fan take out the hot air from right between the cpu and video card..
but i havent tested out this theory so..

anymore input would be great.. thanks.

 

[mechBgon]

What kind of case? A really nice setup would be one blowhole feeding cool air into the cards and a second one feeding cool air to the CPU's intake area, you could do that with dual 80mm or 92mm fans on some cases. I have one case with a 120mm blowhole dead-center over the CPUs on a dual-P3 system. The other case has a dual-Celeron with a 120mm blowhole positioned so half the air is going into the upper cards and the other half is going over the top side of the AGP card to the CPUs (that's my gaming system at the moment).

On the first system, my goal was to cool down the CPUs, especially the rear one, and I tried the exhaust idea first, but the intake worked far better. You could get a Radio Shack digital thermometer and test both fan directions to see what helps most for your system.

 

[VTBigBear]

-mechbgon

thanks ill try 'in' then. and get a digital thermometer.

 

[JJHendrix]

hrmm....i would suggest having cool outside air being sucked in from the bottom front of your computer and hot air from side the case being pumped out from the upper back half. along those lines you prolly want the fan blowing air out right from your CPU and just above your video card.

 

[videotips]

If its cooling a hard drive then blow in... blowing out with suck air from inside the case.

 

[Ulysses]

The honest to God, plain, unvarnished, in yo' face truff is that you can't tell until you've tried it both ways and monitored the temps inside the case. And it's not like it's hard to reverset the fans or something.

 

[Electric Amish]

These are my 2 theories...

My old case I had 2x80mm fans blowing IN onto the video card and a 120mm in the top of the case exhausting the hot air around the CPU. This was on a Celeron 300a

Now I just upgraded to an Athlon with an Alpha heatsink and was going to do the same thing, but I changed my mind due to the case construction.

If you are using an alpha the blows the air up and away from the cpu, you'd want to exhaust that hot air out of the case. If you put the fan blowing in over the CPU, you'll just blow the hot air back on the cpu.

Over the video card, one way or the other probably doesn't matter as long as you have plenty of circulation/exhaust for the hot air.

amish

 

[VTBigBear]

thanks for the input ppl..

i think trial and error will prevail.

=)

 

[Lalakai]

Working with both interior and exterior fans the normal rule of thumb is to have the exterior fans pull air out of the case while using the interior fans for concentrated air flows. A benefit of this (especially if you have a tight case) is that you can determine the air intake areas and have a good dust filter setup to minimize accumulation on the interior.

good luck

 

[EmperorNero]

have it blow IN on the cpu or videocard. b/c you'll have 2 intake fans vs 2 fans that blow out - it's balanced. if you have 3 fans blowing out and 1 fan blowing in, that will create a vacuum, which then makes air get sucked in through little holes on your case..the result? a hell of a dusty case.

just in case, you would want filters for any intake fans. you can buy them or you can make them yourself w/ your mom's or wife's pantyhose.

http://www.ipkonfig.com/Articles/FanFilters/FanFilters_01.htm

that site has a lot of lame jokes regarding pantyhose, but you'll survive.

 

[pvanosta]

This is what worked (very well) for me:
I have 1 120mm fan directly above my Alpha/Peltier cpu-cooler. The fan of the alpha is set to suck, which is then re-inforced by the huge 120 mm fan which also sucks OUTward, creating a windtunnel of hot air being evacuated from my case.

Below that, I have a card cooler sitting behind a second blowhole, which enables it to suck cold air from the outside without obstruction and blow it across my Geforce 2.

Result: P3-700 rock stable at 966 MHz/138 fsb, at DEFAULT voltage of 1.65 V, and running at 100% stress (SETI plus several apps) at 75 deg F.

My system specs:
P3-700 @ 966/136, default VCore
Alpha 6035/Leufkens 55W Peltier with own modification (custom Copper Cold Plate)
256 MB CAS2 PC133 sdram
Hercules Prophet 2 64
MSI 6309 MoBo
SB Live
20 GB 7200 rpm IBM HD.

Case photo available via e-mail on request

pvanosta@netscape.net

 

[helloedchen]

if you put a fan on the side of your case, figure out what direction the fan on your cpu is blowing. If it is blowing out, point it out, if it is blowing in point it in so you don't get a 'vacuum' area.

imo, i don't think that fan there makes a lot of difference. Having a fan in the front and a fan in the back is sufficient enough to provide a good air flow through the system. That fan on the side just causes the air to shift when passing through the MB.