Placement and choice of fans

Tomas_269

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Mar 16, 2017
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Hey, i am looking for some fans for a no-name oem case with not many mounting places, so they will be mostly held by cable ties.

Now, im unsure which ones should i get. I mean, i have m5a97 pro motherboard, external exhaust (blower) gpu and a stock cooler on cpu (the "new" wraith one). Now, where shoud i put them, and which ones to choose? I got one 3-pin case fan connector, one 4-pin case fan connector and smth called power fan connector, which is 3-pin.

I've got space for a 80-90mm fan (the holes on the case are about 85mm in diameter) for a rear fan, placed above the rear io, then a space for a 70mm fan in the middle of the front panel (approx a bit lower than the rear fan) and a space for up to a 120mm in the bottom of the front. And the psu is sitting above the mobo, with the intake fan facing down. Also, all the gaps where the extension cards fit are open, as i got it like for free just for taking it away. Same goes for the dvd drive brackets and a hole for i guess floppy drive.

The system was running few months without side panel, with a slight oc (stable 4,6GHz on FX-4350) and without any case fans (no time+money+will).

The question is, where should i put the fans, and which ones should i buy? I'm on a rather low budget also.

Also, a noob question: are all fans controllable, or do i specifically need a PWM one to be able to control it?
 
Solution
You have only ONE mobo fan header that can control fan speeds automatically. That is the CHA_FAN1 header. In the manual p. 2-22, this one shows pinout functions for a 4-pin PWM control system. The CHA_FAN2 header does NOT do any control at all. Neither does the PWR_FAN header, which really is designed for something different, not for case fans.

Given that, you MUST buy only 4-pin PWM fans. Any 3-pin fan connected to this header will always run full speed. Among the Arctic Cooler line, be sure to get the PWM models. Do NOT get the non-PWM ones, or the "Silent" ones, or the "TC" ones.

To power and control several fans from this one header you will need a 4-pin fan Hub. The simplest of these actually looks like a collection of several...

fry178

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Dec 14, 2015
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Get some arctic cooling ones.
They are the cheapest among name brands and pretty silent for amount of airflow.
You want to use front/lower placed fans as intake, and rear/higher positions for exhaust.
I would seal all other openings with blue painter tape or better use some thin silencing foam with adhesive backing.
Also looks a bit better, as its black and blends in better with the case
 

Paperdoc

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You have only ONE mobo fan header that can control fan speeds automatically. That is the CHA_FAN1 header. In the manual p. 2-22, this one shows pinout functions for a 4-pin PWM control system. The CHA_FAN2 header does NOT do any control at all. Neither does the PWR_FAN header, which really is designed for something different, not for case fans.

Given that, you MUST buy only 4-pin PWM fans. Any 3-pin fan connected to this header will always run full speed. Among the Arctic Cooler line, be sure to get the PWM models. Do NOT get the non-PWM ones, or the "Silent" ones, or the "TC" ones.

To power and control several fans from this one header you will need a 4-pin fan Hub. The simplest of these actually looks like a collection of several cable arms only, with no "box", something like this

https://www.newegg.com/Product/Product.aspx?Item=N82E16812423164&cm_re=4-pin_fan_splitter-_-12-423-164-_-Product

That's one with three output arms, each ending in a male (with pins) 4-pin connector to plug fans into. You can get ones with more output arms. The Hub also has one arm ending in a female 4-pin fan connector that plugs into your mobo's CHA_FAN1 header to pick up the PWM signal. PLUS (and this is what distinguishes a Hub from a Splitter) it has an arm with a male 4-pin Molex connector on its end that you must plug into a Molex female power output connector from the PSU. That last is how the Hub gets power for all its fans, and does not need to draw power from the mobo fan header.

When you do it this way, all your case fans on the Hub will be controlled by the same signal from that CHA_FAN1 header. They may not all run at exactly the same speed if they are not identical fans, but that does not matter at all. Be aware that, when you connect several fans to a single header like this, the speed of only ONE of those fans on the Hub will be reported to the header for display. All the others will be ignored. This is the normal and proper way for them to work.

By the way, the size labels on fans are based on the dimension of one of the square sides of the fan chassis. The actual mounting holes, being set back from the edge, are closer that the size label. For example, the 80 mm fan I just measured has holes spaced 72 mm apart; on a 120 mm fan, holes are 105 mm apart.
 
Solution

Tomas_269

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Mar 16, 2017
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I actually went ahead on the first reply, already got two artics, the basic, cheapest ones. Plugged into cha_fan1,2, working, but right now i can control them only both at once, not separately. But i guess your answer actually solves that.