Case mod for two 4-Pin PWM case fans and Airflow question

PVC

SFF Lingo Aficionado
Original poster
Jul 12, 2020
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The case is a tiny (Size:197mm*197mm*80mm) mini-ITX L80 Case with USB 3.0 on the Right side of the Case=Link. It has the option to add two tiny case fans size=50X10mm on the right side next to the USB 3 ports. This is still in the thinking-about-it-stage but I may want to Add 2x50-x10mm 4-Pin PWM fans to the right side of the case.

But here's the problem. I can't find size 50-x10mm 4-Pin PWM fans. I can only find oversized Noctua 60mm or undersized Noctua 40mm.

Three Questions:
  1. If oversizing or undersizing the fans are both possible, which would preferable from a free airflow perspective?
  2. Should the side fans be exhaust fans or intake fans like the CPU intake fan direction shown on top of the case in the image below?
  3. If I were to abandon the goal of PWM case fans then what is a good/quiet 50x10mm 3-pin case fan?

 
Last edited:

smitty2k1

King of Cable Management
Dec 3, 2016
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Most motherboards offer full control of 3 pin fans these days, so I don't think 4 pin fans is too big of a deal
 

PVC

SFF Lingo Aficionado
Original poster
Jul 12, 2020
124
38
I watched this fan control explanation below; So even if I gain some control over a 3-pin fan (change voltage to get high-speed, or lower-speed) I don't see how to make it infinitely variable speed based on thermal load??

eta: Oh, maybe I don't understand 3-Pin fan control. I was thinking that fan voltage can only be adjusted manually up or down by making a specific BIOS one-time adjustment. Can you instruct the computer to vary the voltage for a 3-pin fan based on a thermal load?

 
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PVC

SFF Lingo Aficionado
Original poster
Jul 12, 2020
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Okay, I see what you mean. I looked in BIOS on my recent In-Win Chopin build. I had replaced the PSU fan with a Noucta fan to lower the PSU fan noise. Currently on CHA Fan 2 it is set to (DC MODE) which I believe, without further control just gives it max voltage. It is currently running at a constant fan speed of 2657 RPM or thereabouts. But I do see where I could apply Thermal controls. Maybe I will experiment further to see how it changes. I am guessing it would lower the voltage for lower thermals.
 

smitty2k1

King of Cable Management
Dec 3, 2016
913
452
Yes, set BIOS to DC for 3 pin fans and use whatever other BIOS fan options you have to set the curve, either manually or with a "silent" or "performance" profile or similar
 

PVC

SFF Lingo Aficionado
Original poster
Jul 12, 2020
124
38
Yep, I did some testing and I believe that 3-pin case fans will work just fine. I can set the fan mode to DC mode and then choose between five settings. Standard setting seems the best for my use. As to airflow direction it is not likely to make much difference. I think I will choose intake so that hot air will not be directed towards me when I sit at my desk. Thanks @smitty2k1
  • Customize
  • Silent
  • Standard
  • Performance
  • Full speed
 
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