PC Case Cooling Fan Sound Reduction

[Kurgen]

Im doing a small referesh / tidy on my PC, and from posts i made yesterday i ordered an Ocuk gtx970 plus an EVGA PSU.. At the moment my PC sounds like a powerstation, all the fans are 3 pin (i only have 1 4 pin on mb and the water coolers using that with a 3 pin header) fan layout is below. there is also a side fan with the dotted line blowing out. The gpu currently is blowing in the case but my new OCUK blows out as indicated. Is there anyway i can thermostatically control the fan speeds so they crank up on their own when needed (Aside from CPU), I have one 5.25 bay free if that helps.

 

[doyll]

Keep in mind what I'm saying below is theory, but is based on years of experience using airflow to cool things. Problem is there are so many variables at play that air often does something we don't expect. We can explain it after we see it happen, but have a very hard time predicting exactly what will happen. You might find this guide helpful. http://forums.overclockers.co.uk/showpost.php?p=26159770&postcount=7

Your top exhaust, especially the front one is drawing cool air from front and bottom intakes right up and out of the case.
Along with the 2nd top exhaust they are drawing the heated exhaust from your GPU up so it goes into your radiator.

The PSU is drawing air in the bottom and out the back.
Unplug fan 7
Raise your case up with some 25-30mm blocks under the feet.
Make sure your grills and filters are clean.
Remove unused PCIe back slot covers
Try unplugging fan 6.
Setup case fans so their speed cycles with CPU cooler and GPU cooler fans .. slow down when they do and speed up to supply needed air when they do.

There are a couple different ways to do this.
http://forums.overclockers.co.uk/showpost.php?p=26079729&postcount=5

 

[Kurgen]

thanks for the info , will have a read over the weekend when i have some time... do make matters more complicated my new psu, is larger than expected and the bottom Fan 5 had to be removed completely

 

[foster grant]

you wont need all those fans with an Nvidia card

 

[doyll]

EVGA GeForce GTX 970 SSC ACX 2.0+ TDP is 145w with 2x 90mm fans. That combined with the radiator is the total airflow requirement of system. Add 25-50% more to move heated air away from cool air and we need 3x 140mm fans. 2x front and 1x bottom intake are plenty.

If we use the fans as shown by Kurgen cool air from top front fan will flow up and out of top front fan and the heat from the 970 will flow up in front of radiator and be drawn in.

I propose something like this

If case is a Define R2 / R3 / R4 the above will work well, especially if the intake fans are speed controlled by GPU and CPU cooler heat. I know because I've built several this way including my sig rig. CPU is never above 55c and GPU never above 65c .. and all at less than 36dBA noise level.

 

[Kurgen]

remember i had to remove fan 5. the EVGA psu i installed ends up as far as 50% over the first cable management grommet. funny you mention about the cpu heat,, i have noticed mine increase since i installed these.. would removing fan 6, and setting 7 as inflow work and setting the side fan 8 thats currenlty blowing out to blow in across the GPU

 

[doyll]

Block fan 6 vent and try fan 7 as intake.
Remove the unused PCIe back slot covers. I know they are vented, but they still block 40% of the airflow area. Check them to see if air is flowing out or in through them.

Edit: Could you use a 120mm fan in bottom intake?

 

[Kurgen]

Block fan 6 vent and try fan 7 as intake.
Remove the unused PCIe back slot covers. I know they are vented, but they still block 40% of the airflow area. Check them to see if air is flowing out or in through them.

Edit: Could you use a 120mm fan in bottom intake?

no room im at work , but took this pic of psu mid install last night, see how far over it is, and without the cables installed, there would o airflow even if i could squeez it in

and the power going out of the case is for a custom control panel for elite dangerous incase your wondering