case airflow opinion / change cpu fan to intake?

Slam · 18 Sep 2016 at 22:25

I have an In Win 303 with 7 case fans (all 120mm):

3 intake: Noctua NF-S12B, 59.2 cfm
4 extract: 3 x Antec TrueQuiet UFO, 46.3 cfm and 1 x fan supplied with case (spec unknown)

I want to achieve positive pressure but I assume that the cpu case extract fan offsets the difference between the Noctua and Antecs. This is the current setup (middle row of 3 fans are the Nitro Fury gpu fans):

In%20Win%20303%20vent%20diagram%5B1154449%5D.jpg

Should I:
a) remove the cpu case extract fan and rely on other 3 extract fans
b) change cpu cooler and cpu case extract for Corsair H80i v2 and setup fans to intake
(https://www.overclockers.co.uk/cors...iquid-cpu-cooler-cw-9060024-ww-hs-037-cs.html)
c) leave as it is
d) or other?

Slam · 18 Sep 2016 at 22:26

This photo may help explain current setup (the case is slightly unusual)

doyll · 19 Sep 2016 at 13:07

If I understand correctly, you have 3x bottom intakes, 3x side exhausts near top and 1x rear exhaust. This setup means case airflow is bottom to top with heated GPU exhaust air supplying CPU cooler.

Nice looking cases, but terrible airflow!

Slam · 19 Sep 2016 at 15:44

Yep you understand things correctly

I think that the temps are actually okay, up to 65c for both CPU and GPU but yes the cpu gets the heated air (main difference is that cpu idle temp is higher than before). That's why I'm thinking about about an aio cooler using the rear exhaust position as an intake. This might mean a higher air temp inside the case though, depends on how efficiently the current setup expels cpu air.

doyll · 19 Sep 2016 at 17:27

You can try it. Worst case is you just have to turn things back around.

Slam · 25 Sep 2016 at 17:42

doyll said:
This setup means case airflow is bottom to top with heated GPU exhaust air supplying CPU cooler.

hang on a minute... gpus heat air and are positioned just below the cpu. what cases prevent this?

doyll · 25 Sep 2016 at 17:59

Slam said:
hang on a minute... gpus heat air and are positioned just below the cpu. what cases prevent this?

Sorry, but it seems you need to turn on your brain.

If airflow is bottom to top .. airflow is mostly up.
If airflow is front to back .. airflow is mostly toward the back of case.
Not rocket science needed to understand air moving horizontal moves the heated air from components in the same horizontal direction.

Basically like up-drafts and down-drafts versus horizontal winds in our atmosphere.

Slam · 27 Sep 2016 at 10:13

Front to back is a bit of a simplification though. Don't most cases vent out the back from above the gpu position? (Unless the gpu cooler design directly expels air through the expansion slot area)

This being the case, the heated gpu air must generally pass over the cpu cooler (surely?)

(I accept that I don't always fully engage brain before typing!)

doyll · 27 Sep 2016 at 12:03

told you what I've found out after monitoring airflow and temperatures at different places inside of the case.

GPUs expel heat air in most all directions inside of case.
Most CPU coolers are at least as tall as GPUs are.

Your 'disclaimer' about brain engagement do not excuse not thinking about what you are asking.

Sorry, I couldn't resist hitting you while you were already off balance.

Just look at the pic you posted. The intake is in bottom and GPU is dumping heated exhaust in all directions. The front fan in bottom is pushing air up around the front of GPU, so heated air coming out of GPU front is mixing into that cool air as it moves toward the CPU cooler. In you case (pun and not) cooler is quite small. Smaller than most, so probably not much of the heated air coming off the GPU top (farthest away from mobo) side is mixing into CPU airflow.

You could baffle / duct the bottom front fan's airflow up past the GPU and into CPU fan, but I don't know if it is worth the effort.