s340 elite fan configuration

[cytoSiN]

Hey guys. I've got a question re: fan config in the s340 elite, which has two 140mm front fans, one 120mm rear fan, and one 140mm top fan.

I have a 280mm rad in front (Cryorig A80 with the included Cryorig 140 fans), with both fans as intake in push config through the rad. Yes, this moves warmer air into the case through the rad, but there's no other choice in this case. At least the whole front panel has an easily removable mesh filter.

The rear fan is a 120mm Noctua NF-F12 and it's exhausting through the 120mm rad on an EVGA 1080 FTW Hybrid.

So my question is what to do with the top fan. I have a Noctua NF-A14 up there, currently set to exhaust. I could flip is to use as intake (I'd add a mesh screen if I did that) to create (more?) positive pressure, but I'm not sure that's necessary? I've also got the 80mm fan on the A80 pump, which can point in any direction and be set to push or pull. It's not doing anything but helping to move the air in the chosen direction, but it could help by pushing air towards the rear or top exhaust, or if I flip the top fan to intake it could help force the intake air down to the GPU backplate.

Any help/comments appreciated. Thanks!

 

[Paperdoc]

Personally, I prefer slight positive pressure, as ling as you use intake dust filters. How to be sure you achieve that is almost impossible by calculation. BUT you can find out by experiment. You need a small source of smoke. I've used a smouldering incense stick. With the computer running, move the smoke source close to the case where there are cracks like at a CD or floppy slot. Which way does the smoke go - in or out? This tells you how the air flow is balanced.

 

[cytoSiN]

Thanks. I'm familiar with how to check it, I'm just curious what's best. If I flip that top 140mm fan, I'd only have one exhaust fan, and it would be the 120mm through the GPU rad on the rear of the case. So it would be strongly positive pressure. So I'm not sure...I'm planning to finish the build with the 2 exhaust, and we'll see how it goes. But if anyone has other thoughts on which way is best, I'm all ears!

 

[imported_jjj]

Why intake for the rad?
Seems counterproductive and worse than air, especially in this case.
Anyway, the top fan as intake would at least help the GPU a bit and divert some of the hot air that comes from the front rad.

 

[cytoSiN]

You mean in the front for the 280? Because the idea is to bring cool air from outside the case over the rad to cool it as effectively as possible. Otherwise I'm blowing warm air over the rad from inside the case. Also, if I flip those fans, the case will almost certainly be negative pressure, which is also bad. I've never seen anyone mount a front rad in an s340 elite as exhaust, but maybe I'm just missing something?

 

[imported_jjj]

The rad is hot , the air in the case not so much.
Water cooling takes the heat away from the chip and gets it to the rad so you could blow it out as exhaust through the front.
Sure you wouldn't have enough intake and it would get a bit dusty as air comes through the PCI slots.but it would be cooler, especially the GPU.

If you blow hot air in the case, you increase the temp inside the case, the goal is to cool the chips so if you go from 30 to 35C, that's not good.

 

[cytoSiN]

Sure, that's why I would typically mount the rad as a top exhaust, but that's not possible here... and I need the rear fan as exahust because of the GPU rad. If I flip the front fans to exhaust, and go intake on top as the only intake, I could tape over the PCI slots to minimize dust?

But for now I'm going to finish the build as is and if the GPU temps are too high, we'll see about changing things up. NZXT has actually recommended front intake on the case despite the issue, including for SLI. And they've reported temps being well within normal operating range. So I'll see how it goes. For now, I'm focused much more on the direction of the top fan (and the 80mm fan on the CPU pump) than the front rad.

 

[imported_jjj]

Just try as intake and the top as intake to help the GPU rad.
Guess it does depend on the fan's speed for the front rad. If they aren't dialed down too much, it should work ok as you would have strong positive air pressure.

 

[cytoSiN]

Yeah that's exactly what I had in mind. And the 80mm fan on the CPU pump is small but powerful, and will also help move the air.

 

[imported_jjj]

You have the system so you can test in any way possible,maybe share the results.
Maybe play with diff speeds for the top fan , see if there is a best setting for GPU temps.

 

[cytoSiN]

Yeah, just getting opinions before I spend the time making it super clean. The rear and top fans are Noctua industrial 3000s. They're serious fans and I don't care how much noise they make. I'm still tempted to use the top as exhaust to help rip the hot air from the front out the top, but if the GPU gets too hot I'll flip it (and the 80mm pump fan).

 

[imported_jjj]

Top as intake would help the GPU rad and maybe even blow some cooler air on the back of the GPU's board.

 

[cytoSiN]

Yeah, I agree. Need to get a filter for that fan tho.