Noctua fans, C70, PWM and case cooling questions

Narada

Narada

Narada

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I'm doing a C70 build. I've already decided on a NH-D14 SE2011 cpu cooler so don't need to worry about static pressure fans. But given that the C70 has umpteen bazillion 120mm fan mounts I need to decide on two things.

1. A decent 120mm fan.
2. PWM or no PWM for use with a Lamptron FC5V2 fan controller.

For #1, based on Noctua's website advice (http://goo.gl/hnv3Q), I decided on the NF-S12B FLX (http://goo.gl/7K7KD) as it was the best airflow fan they had. However then I realised that this is 3pin and does not support PWM whereas the NF-F12 (http://goo.gl/1S8IR) which is best for static pressure, being 4 pin, does support PWM. So now I'm a bit confused and need some help. My questions are:

1. Given that NF-S12B FLX does not support PWM -if I plug it into a fan controller like Lamptron FC5V2 or a mobo header - will it always run at max speed (assuming no use of the low noise adapters)?

2. If fan controller voltage is turned down will NF-S12B FLX just turn off if voltage is inadequate?

3. Why do they not have PWM for their airflow fans and only for static pressure fans? Is PWM not necessary for airflow?

4. I've noticed that some reviewers out there use NF-F12 for everything which I'm finding a bit strange. Why would you need static pressure fans for case cooling? Is it because they support PWM?

Would appreciate some light on the above from the experts. Thanks.
 
1. It will be controllable like any other fan if connected to a controller. Some mobo's (like mine) allow speed adjustment on 3pin fans. If not, it'll run at full speed unless you use a voltage reducer.
2. Turn the knob down and the fan will stop spinning.
3. PWM has nothing to do with airflow, it's just a different way of controlling fan speed.
4. Probably simply because they're good fans either way.
 
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1. A fan controller will allow reduction in fan speed while a fan header typically will not.

2. If it goes that low.

3. PWM is just a method of fan control. Some fans have it some dont.

4. A fan is a fan. High static pressure if good for heatsinks but still shifts air in an out of a case.
 
Thanks guys. So correct me if I'm wrong. A fan speed can be controller by either adjusting voltage or by PWM which are two different methods. So even though the airflow fan may not support PWM it can still be adjusted through voltage? And I'm guessing Lamptron FC5V2 uses voltage control?
 
If it doesn't support PWM, it can only be controlled by voltage.
Yes, the Lamptron uses voltage control.

One thing I'll add is that I've found that while PWM fans can be controlled with fan controllers, the operating range can be reduced slightly compared to running off the mobo.
Tealc will know more about that I hope :)
 
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I use an FC6 (20W) with 2 fans per channel (have used 3) with no probs. You'll be fine.

Those splitters are fine. Ugly, but should be ok if they're tucked away ;)
 
Thanks. Yes I agree they are horrible. I'm all for aesthetics so if you know better looking ones do share. :) Though to be honest the aesthetics will already have been devastated by the use of Noctua fans anyway so it won't matter! Lol!
 
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Petey is quite right. PWM fans do tend to have narrower operating speed ranges than a comparative 3 pin fan. I've noticed too that my PWM fan doesn't start until at least 8v and stops basically before any of my other fans when supplied by the same controller. Must be something to do with bearing design.

3 pin fans can be used on motherboard PWM headers if you use a converter such as the one I designed.
 
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