Intake or Exhaust Side fan!

andy - Are you referring to a fan on the side panel of a pc case or the heatsink fan on the video card? In a typical configuration both fans are intake fans.

I've reworked my current P4 system with an AGP 6800 Ultra and I found the side fan works better as an intake to give the GPU its own air source - changed it to an exhaust a few nights ago and load temps have gone up a bit so I'm switching back.

He's saying will it help since he has an aftermarket cooler on his video card. With that known (either way really) I think the side fan is designed to be INTAKE. You should have a rear exhaust fan and maybe a PSU exhaust fan so the more intake you ahve the better .. it will keep air flowing over your video card and CPU. So .. get a good intake fan that moves a lot of air .. because that will certainly lower your case temps. ^_^

It is highly advisable or should i say, MUST do to make the side
panel fans as intakes rather than exhausts.
The nature of hot air inside your case produced by different components
installed is to rise up and it would be difficult for those hot air
to exit on the side even though it was being suck by those side panel
fans converted as an exhaust because before it goes through
the side, the majority of hot air will just be sucked again by your
procie and video card cooler fans, so most of the hot air will just
recirculate again and will cause your system to run more hotter than usual
specially if your have a highly oc'd procie and video card.

That is why if you notice the best enclosures around today
specially for gamers and enthusiasts are designed
with their exhaust fans placed topside (usually two 120mm fans
or in single of 140, 200 or 230mm fan) and the other is on
the rear side (usually a single 120mm fan) placed slightly on upper
part in parallel with the mobo's external ports.

This is to make the hot air inside your system leaves naturally and easily without
any distraction or disturbance, since it rises up, helping those hot air exit
based on its behavior would add to the enclosures cooling performance
and efficiency.
In general, since cold air can be sucked easily through the side
panel intake fan(s) and or though the front intake fan(s),
hot air is easily replaced by cold air thus resulting a high air flow.

-- This means your internal components are provided direct cold air
all the time which they need perform better and to last longer.

If you read the case manufacturer's documentation, I'd bet it's labeled as an optional intake fan.

Reading up on it intake is best in most situcations, but it can depends on the position of the side fan and if your GPU vents any hot air into the case (like the GTX295 does). If you do have a graphics card that vents into the case and the side fan is positioned over the graphics card you will probably get lower temps removing that hot air straight out the case, rather then blowing air directly into the hot air coming out of the GPU.

Simplest answer is try both and see what temps you get.

I understand the theory of sucking hot air out however it wont actually work like that.

The gap between the side fan and the video card cooler is not sealed, only a small portion of the hot air will make it out the side fan, most of the air coming out will be cooler air that came from the front of the case.

Looking at that video card heatsink design, most of the air should come out the sides.

Set it as an intake, otherwise you're wasting intake air. More air flow is good.

The problem with using it as an intake is if the fan is more powerful then hot air coming out that hot air is going to get blown straight back onto the graphics cards and motherboard which isn't going to do anything good for the temp in the case.

I did some playing around with side and top fans (CM690 case). You can get a good idea by monitoring cpu & GPU temps. I also mounted a temp monitoring thermister about 2 inches in front of the CPU fan. My CPU fan blows toward the rear and a top mounted exhaust increased CPU temp (I should remove HSF and point toward top). Monitering proble was one of though $10 inside/outside temperature units from walmart - Not the wireless type.

Any way, I modified my side and placed a side fan top back courner as an exhaust and then placed a intake lower front corner. My CPU is on the bottom and intackes from the bottom Vent holes and out the back. Front fan intake and rear exhaused. You want to balance the intake and exhaust. To many exhaust leads to air being suck in from places you do not want, ie thru the DVD drives - leads to dust inside DVD and on Lens. Also posibly neg air pressure which reduces cooling. To much intake also has its problems.
Bottom line is experiment and find what is best for your setup.

OK, I will make the side fan intake then. Thanks guys!

Just make sure there's some kind of air filter installed or the interior will soon be covered in dust.