Airflow in NZXT S340

elrasho

elrasho

elrasho

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Since installing a 1080ti I've been monitoring overall temps in my case.

After a few hours gaming I notice a couple of my cores hit 72C and GPU gets to 68C. I looked at my fan placement and this is what I have:

1. 120mm at back blowing cool air in
2. 120mm at the top blowing hot air out
3. Corsair H45 mounted at the front blowing hot air out

I was thinking of installing another 120mm fan under the H45 fan sucking cold air in. So them id have cold air coming in from the bottom front and back and being blowed out the top.

Will that have a good cooling effect? I have a very aggressive fan profile setup on my cpu and gpu (if temps hit 50 the fan go to 80% and if hit 60 the fans go to 100%).
 
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So I took the front cover off my case and temps have gone down by 10C across the board. I think this case has a design flaw, I'm gonna get another 120mm fan and have it blowing hot air out towards the front:

(how do I resize pics?)

hjUWEc0.jpg
 
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Ignore cfm, pressure is what is needed to overcome resistance. 45 is quite low cfm anyway i believe, any resistance will cut that right down.

Can you fit 140s?
 
Unseul said:
Ignore cfm, pressure is what is needed to overcome resistance. 45 is quite low cfm anyway i believe, any resistance will cut that right down.

Can you fit 140s?
Click to expand...

According to their website I can :

Fan Support Front: 2x 140/2x120mm
Top: 1x 140/120mm (1 x 120mm FN V2 Fans Included)
Rear: 1x 120mm (1 x 120mm FN V2 Fan Included)

Which 140mm fan would you recommend?
 
Phanteks 140MP are good for pressure and price, and pretty quiet. Others can spin faster, and build up more pressure and flow, but at greater volumes.

The industrial noctuas produce good pressure (but you'll pay a premium for it to be noctua as well).

Can you put your radiator as the exhaust on the rear, then a pair of 140mms on the front (the phanteks come in a very very cheap pair bundle at OCUK, about £16).

That'll give you much better flow.
 
You need to be refreshing the air in the case to cool the components.

Right now i would say that isn't happening. The cold air from the rear in is being sucked straight out by the top fan that is adjacent to it.

Change the front fan on the rad so it is pulling air from the front. Add an additional fan below that also pulling air from the front.

Set rear fan to exhaust. Set top fan to exhaust, or if required, move it to the front and close the top vent leaving just the rear as exhaust.


You want to make sure you are exchanging the air in the case. Doing the above should help.
 
Am I simply flipping this fan over to get it to suck cold are in, won't it just suck the hot air emitted from the radiator?

K3y7I43.jpg
 
If you are sticking with 3 fans and closing that top vent then you should have positive pressure within your pc case from the 2 intakes vs single exhaust.

One final thing you can do as long as you do have positive pressure in your case is to remove the pcie covers nearest the GPU to allow for more airflow.

By having plenty of air being drawn in at the front, the positive pressure inside the case should keep dust down (except on front intake) and force the hotter air out through the pcie slots nearest the GPU.

The rear exhaust should take care of the rest.

You can experiment with removing the pcie slot covers regardless of your fan setup to see if it helps, but having the sort of setup above would get the most from it. The empty pcie slots become a passive exhaust that is adjacent to the 1080 ti and perfect for avoiding heat build up in that location.


Obviously your fans, their speeds and any airflow restrictions will all have an impact so you can look into altering that if you don't get the results you want.
 
elrasho said:
Am I simply flipping this fan over to get it to suck cold are in, won't it just suck the hot air emitted from the radiator?

K3y7I43.jpg
Click to expand...

You would flip the fan yes.

Or alternatively as suggested above you could mount the radiator on the rear of the case as an exhaust and leave the fan as it is. Then you could put both your other fans in the front as intakes and they would suck in cool fresh air which would cool the pc as a whole and be expelled by the radiator fan.

That might be the optimum setup.

It might not, but I would think it is worth trying to see which works best for your pc.
 
Hmm I don't see how sucking cold air will work with my case, the gap for air intake is very narrow:

Q4OW3DM.jpg


I cant mount the radiator at the back, case bits get in the way
 
Air enters at the top and the bottom of that front panel. It isnt the best case for airflow, but it was designed for clean looks which come with compromises.

You should still get decent airflow through the front. Just not class leading.
 
If you can't fit the rad on the rear because of clearance issues then you could try fitting it in the top spot as exhaust instead if that has more room.

So long as you have 2 intakes at the front to ensure that the air in the case is constantly being changed.
 
I'm currently running no side and no front on my S340 Elite... it just isn't a great case for airflow!

BF1 would crash the PC, even with a 50c CPU and 74c GPU. Must be bad airflow elsewhere.
 
Flipped the H45 fan so it's sucking cold air from the front, cpu temp on average are just 52C under load! What a difference that has made. So now I have the rear and top fans as exhausts and if I put my hand over the rear I can feel the hot air so it's a good setup :)

GPU is hitting 60C which I'm Ok with albeit the fan on it running at 100%. Tempted to get another fan for the front to suck cool air in and help the temps on the GPU.

Thanks for the advice @Distracted

EDIT: I don't think I can fit another fan at the front, the Corsair H45 is so big it takes up a bit of the room in the bottom slot post #4). I could mount a fan at the bottom but it would be inside the PSU shroud so won't be as affective
 
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