Cooling Fan intake clearance

[robbee]

Howdy!

I've recently purchased the Noctua NH-L12 as cpu cooler. I was planning on using in its as single fan mode, where they advise on mounting the 92mm fan bellow the heatsink. I noticed now that I can also mount the 120mm fan below the heatsink, due to my low-profile memory.

The clearance between the fan and the mobo isn't a lot though and I'm worried I'm choking the fan. Is there a rule of thumb about how much clearance is ideal? I think i have about 10mm now. With the 92mm, it would be 15mm-ish as it sinks deeper into the heatsink.

 

[ricochet]

http://caspar.panwagen.ee/?p=963

 

[ricochet]

What CPU are you using with this?

Noctua's have been designed to need less headroom (breathing room) than some other fan brands.

The Noctua NH-L12 was designed to function in low-profile HTPC builds with only the bottom 92 mm fan installed so that may be good enough... I have seen many ITX builds with this cooler where the top area is too tight for the top fan so a bottom fan (both 92 and 120 mm) only configuration is used instead... so you will not need any top side breathing room, especially if you aimed the bottom fan upward (could be more noisy though). The above link has some pics of a 120 mm fan in the bottom position and I believe this fan set-up was pushing air upwards into the radiator.

 

[robbee]

What CPU are you using with this?

i3 6100 but that might change to an i5.

http://caspar.panwagen.ee/?p=963

Almost how i fit mine, only mine blows upwards. Are you saying that that's actually the better setup?

 

[ricochet]

i3 6100 but that might change to an i5.



Almost how i fit mine, only mine blows upwards. Are you saying that that's actually the better setup?

Yes, almost every bottom fan only set-up I have seen in tight HTPC builds has been a fan upwards operation though I do remembering people saying it can be a little noisier that way.

Is the panel above the CPU Cooler Radiator vented? Then the upward configuration might be the best option for you.

 

[robbee]

Is the panel above the CPU Cooler Radiator vented? Then the upward configuration might be the best option for you.

Yes it is. Problem is that even at 100% fan speed, I can only faintly feel air coming through the heatsink. That's why I'm suspecting that I'm actually chocking it by leaving so little room between the motherboard and fan.

 

[ricochet]

Yes it is. Problem is that even at 100% fan speed, I can only faintly feel air coming through the heatsink. That's why I'm suspecting that I'm actually chocking it by leaving so little room between the motherboard and fan.

Again, Noctua did design this cooler to be used in the bottom fan only configuration with mid-range TDP CPUs and using only the 92 mm fan mind you... with either the i3 or i5 I think you are well within the design parameters that Noctua had in mind.

 

[ricochet]

What are your temperatures like?