Silent big fan for DIY NAS

[Dodo67]

Hi all,
I'm looking for a quiet fan to put into a DIY NAS that I'm building using some recycled components (list on the bottom). I used an Ikea cabinet (Tutemo) as case, using only the four sides while leaving the back opened. I rotated it so the open sides are on the bottom and top and the hot air can flow naturaly to the top. The open sides are 36,5x36,5 cm.
My idea is to find a big and silent fan to put into the cabinet, in top position, to cooling all the components together (mainly CPU and PSU).
My first choise was the NOCTUA NF-S12A FLX, very silent but low air flow, and is only 120mm. Is it enough?
I read that instead of many small fans it's better a single bigger one, with lower speed (and so lower noise).
Can you suggest a big (>140mm) fan with low noise level?
Thanks in advance.

These are the components i used for my NAS:
- an old Asus p2b motherborad (slot1) (P2B Manual)
- an Intel Pentium III 550 MHz CPU
- PSU (AOpen FSP235-60GT - 235W)
- 3 SDRAM modules (256MB each)
- a 10/100 network card (Hamlet HN362TXW)
- a PCI SATA card (Promise SATA300 TX4)
- one (by now) HardDisk WD Red 1TB

Inside there is also:
- a Raspberry Pi, to switch the nas on and off and for other future monitoring uses
- a TP-LINK 5-ports ethernet Switch
- a usb hub connected to the Raspberry, both for powering it and for more USB ports

 

[Darkbreeze]

Is the fan header you are intending to connect the fan to a 3 or 4 pin, or are you intending to use a molex connector, or some kind of hub/controller to control the fan speed?

 

[Dodo67]

Hi darkbreeze,
thank you for your quick answer.
The motherboard only allows 3 pin fans, so the easier solution is to use one of that. I could start with something simple and eventually upgrade to a more complex solution in the future. For example it could be nice to use the Raspberry Pi to monitor the CPU temperature and control fan speed.
At the moment I would install a simple fan with constant speed. The Noctua NF-S12A FLX has two adaptors you can add to the standard cable to reduce the fan speed from 1200 RPM to 900 or 700 RPM. But it's only a 120mm fan, while my (atypical) case has a large aperture. My doubt is that a small fan would be very inefficient in a large box like that. What do you think?
Isn't it better a 200mm or 260mm fan? Consider that I'll remove the small very noisy CPU fan (only the passive heatsink will remain) and if possible the PSU fan as well (my initial idea was to build a fanless system).
Thanks.

 

[Darkbreeze]

Personally, I think the Noctua NF-A14 industrialPPC-2000 would be the best choice as it has a very high quality, very long life bearing design, moves 110 CFM at full speed and even at it's full speed of 2000 RPM it only has a 31db SPL. Chances are good it would most commonly never need to run at that high of a speed since half that CFM is enough to clear most cases several times per second.

If however you want something bigger, the few and only choices I'd suggest would be these:

http://www.newegg.com/Product/Product.aspx?Item=N82E16835345031&cm_re=200mm_fan-_-35-345-031-_-Product


http://www.newegg.com/Product/Product.aspx?Item=9SIA1K63563078&cm_re=megaflow_200mm-_-35-103-178-_-Product


http://www.newegg.com/Product/Product.aspx?Item=N82E16835345032


I'm unaware of any quality, reputable 260mm case fans.