External fan powering?

katie279 · 26 Dec 2018 at 23:17

Hi folks,

Got a big Ikea cabinet that has my (growing!) colelction of Synology NAS units and general tech stuff (eg housing the network switch for the room with all 8 ethernet cables running out etc).

It's getting pretty toasty inside when I close the doors and looks untidy to leave open so here's the plan.

1. Use jigsaw to cut out some 120mm squares
2. Use my 3d printer to fire off some neat fan grille covers to trim around the hole
3. Attach PC case fans to bottom and top of unit to suck in cold and spit out hot
4. Bask in my warmer room, cooler cabinet and handiwork....

The question:
What's the best way to power these fans?
I'm always amazed there isn't such a thing as an external PC PSU supply (ie to power fans, controllers etc).

Option 1 - Get a PSU and bung it in the cabinet (would want fully modular as will only really want PSU fan cables). Advantage being this is nicely future proof (eg with extra things I could extend, eg temperature monitor, fan controllers etc etc!)

Option 2 - Get a cheap 12V power supply and hack it to work with the fans. Cheaper, but less controllable (eg fan speeds) or extra connections.

Am leaning towards option 1 out of sheer simplicity - unless anyone has an option 3????

If it seems sensible, does anyone know the cheapest possible fully-modular PSU? Really don't need high watts naturally and couldn't give a hoot about usual stuff (eg 12v rail stability etc) - as long as relatively reliable, it'll be in pretty low strain for its whole life.....

Many thanks in advance!

bremen1874 · 27 Dec 2018 at 00:02

Try creating the holes and adding the grills without fans first. The extra ventilation may be enough on its own.

Radox-0 · 27 Dec 2018 at 00:15

You could pick up a cheap molex power adaptor, quick google search will bring up some around the £10 - £15 mark. Throw on a cheap molex powered fan hub, something like this maby https://www.overclockers.co.uk/lian-li-li-pt-fn07-ca-632-ll.html could do the trick for controlling and powering external fans.

tyler_jrb · 27 Dec 2018 at 00:38

I’d say like Bremen says put some ventilation first as it likely would be enough.

However if you really wanted to then just get a cheap 240v to 3v-12v adjustable power supply.

Cut solder on a 3 pin fan header/connector then plug the required fans into that via splitters. That way you can get some appropriate wire and run them all out of sight.

Or you could cut the splitter back and solder to that directly, doesn’t really matter. With it being 3v to 12v you have some adjustments for noise.

Plus they are pretty cheap too, around £10 and around 30w is so plenty to power a couple of fans.

LuckyBenski · 27 Dec 2018 at 02:08

For case and fan testing I usually have a 6V and a 12V supply with pins going to a breadboard. I can use jumper leads to each fan and see how it sounds at those voltages. Realistically you could buy a bag of resistors and just breadboard/copper strip board the whole setup. Buy a sine 12V DC supply, clip the ends off and fit the resistors then the fan plugs. Use splitters for multiple fans. Job done.

I'd be tempted to simply feed 12V on a wire out of one of your PCs though.