Best fan configuration for a Demon ATX case

[MasterShazbot]

Here's a tricky topic.

I've got a Silver Demon case, and it comes with 2 80mm fans.

One is on the side with the glass display; the other is on the back of the case (below the PS).

By default, the fans are set to suck heated air out of the case. However, there's no air flowing in that way.

I turned the side fan around so it will blow air into the case, while the rear fan is still sucking hot air out (although it does feel cool, because the warm air is coming from my dual-fan 500 watt PS, conveniently located over the CPU).

My heating problem is not with my CPU, a 2.4 GHz P4 (which cannot be over clocked because of my MSI SIS MB) that stays cool with the stock Intel jet engine (going to have to get that replaced sometime). My PNY 5900 has a bit of a heating problem. I'm using the stock fan and I'm slightly OC'ing it. It idles at 50C right now. Yeah, PNY's jet engines really suck at cooling, but I'm not sure if I want to get an aftermarket cooler now or wait until I upgrade my video card.

Anyway (ahem), I thought that by turning the side fan around, the cool air would help cool the card off. Before I did this though, just for fun, I took both fans out and pulled the side panels off to see how the Temp changed.

My 5900 idled at 47C when I did this, but you could hear my rig roaring 20 feet away (good thing I use headphones. Did you know those can completely remove the problem of having a noisy computer? Try using stock fans with Sony sport 2 headphones & BF2, all you can hear is stuff blowing up in BF2 because the earphones prevent sound leakage ).

After I put the panels back on with the side fan backwards, the card's temp went back UP to 50C, instead of staying at 47C. I think this is because the PNY fan is approximately directly underneath the side fan, so it doesn't get hit by the airflow, and the PNY fan is in the under-side of the card.

Would it make a difference if I made both of the fans intake or outtake? Or should I have one intake and the other outtake (that means should I have one blowing air in and one out, or have both do one thing)?

 

[Nitestick]

depends if there is another decent ventilation source in the computer or if basically the fans are the only inlets/outlets. i would say have the rear fan as an intake and the side as an outtake

 

[FghtinIrshNvrDi]

If it's similar to my case, you may try having two intake fans. My case has so many holes in the back of it, air displacement forces the air out on it's own. It doesn't need any suction. But if your case is pretty well sealed up, try and keep the intake and exhaust fans equal. Good l luck, and play around with it. Find the best combo of fan placement.

Ryan

 

[Him]

depends if there is another decent ventilation source in the computer or if basically the fans are the only inlets/outlets. i would say have the rear fan as an intake and the side as an outtake

No. For optimal air flow, you want intake on the FRONT and exaust on the BACK. Any side fans should be intakes as well. You then want all the hot air to be pulled out through fans that are at the top of the rear of your case (close to the PSU) since hot air rises. Also make sure that you have your side panels on at all times for optimal air flow. You want all the air directed, and going in the direction that you want it to go, not the direction it wants to go.

Like the Irishman said, keep an equal intake/exaust ratio. If you need to, have more intakes than exausts. If you cant have any exausts for one reason or another, have them all intakes on the front. With that, air displacement, like the mic said, will force the warm air out o f the case.

 

[ohGrFreak]

My case is similar, it has a side fan as well. I did some rearanging and I also bought a cheap 4 dollar fan. I set it up like this: front fan intake, side fan intake, rear fan exhaust. I wouldn't worry about having an equal number of intake fans to exhaust fans, because if you have more intake fans, they'll just push out the air faster even without the same amount of exhaust fans.

Anyway, my temps dropped at least 5c, if not 10c. Under load, my P4 3.2e gets around 43c, that is with stock HSF and in a hot room with another computer.