Case fans being choked.

Discussion in 'Overclocking & Cooling' started by TaintedSquirrel, Jun 9, 2017.

  1. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    I'm running a Define S with 3x140mm in the front.
    If I attach the dust filter OR the front panel, it cuts my airflow approx in half with each piece.

    Are there any sort of long screws or a mounting bracket I can use to move the fans farther into the case by maybe 2 or 3 inches to clear up their intake?

    [​IMG]
     
  2. W.Feather

    W.Feather [H]ardForum Junkie

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    How are you measuring your airflow? A filter should not cut your airflow in half
     
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  3. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    My hand.

    Here's what the filter looks like.

    [​IMG]
     
  4. Ocellaris

    Ocellaris Ginger Ale, an alcoholic's best friend.

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    If the filter is that restrictive (which I doubt), spacing the fans isn't going to help.
     
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  5. W.Feather

    W.Feather [H]ardForum Junkie

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    Exactly this.... If your fans lose half their effectiveness, and the hand is not the best way to determine flow....a filter (especially one like that) is not lowing the air intake.

    Even by moving the fans off the filter , you wont eliminate any barriers, thus the total pressure buildup on the fan is the same, There are methods you could use...maybe the "Silencer" pads for the 120mm fans, with some standoffs would be able to accomplish what you are looking for in the aesthetics side, performance wise you would not see any difference.
     
  6. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    The difference in airflow with and without the filter is drastic. So yes it's definitely restricting the fans unless its spirits from beyond the grave screwing with me.

    Should I tape a piece of yarn to the top of the case to check it?
     
  7. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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  8. W.Feather

    W.Feather [H]ardForum Junkie

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    Id be most concerned with the filter off lack of airflow than anything.... You are going from partial airflow to little airflow....What fans are these?
     
  9. Brian_B

    Brian_B Gawd

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    Get some high static pressure fans.

    Any fan is going to drop some from installing a filter. The question is, is the air flow adequate enough with the filter on?

    If the fans are dropping that much from just a filter such that your not able to control temps in the case, they need to be replaced anyway.
     
  10. pendragon1

    pendragon1 [H]ardness Supreme

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    solution = ditch the filter AND get better fans. fuck filters and learn to clean the case!
     
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  11. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    They're GP-14's, Fractal's 140mm.

    Yeah the thought has crossed my mind. Although I'd much rather just find a solution here, even if it means getting creative.

    Definitely not an option, my house is a dust bowl.
     
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  12. pendragon1

    pendragon1 [H]ardness Supreme

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    fair enough. i just preferred cleaning more often over sacrificing airflow.
    just looked at the fan specs; what speed are you running them at? they are supposed to push 68cfm which isn't bad and your vid clip does not look like that much airflow. crank em up and see what happens. otherwise I think Brian is right, youll need high sp fans to pull through the filter.
     
  13. Ocellaris

    Ocellaris Ginger Ale, an alcoholic's best friend.

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  14. THUMPer

    THUMPer Loves Chachi's Tiny Penis

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    That filter design is shit anyway. They restrict it with an aggressive filter, then add all those cross pieces further adding to the issue.

    The fans need replaced, but honestly I don't know if that will help. I have some Gentle Typhoons, and while they help on some filters, they don't help a lot. They seem to be just right for my Lian Li case though.
     
  15. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    They're running off molex, so full speed (~1000 RPM).
    Based on the noise I'm not sure I'll actually run them at full speed regardless.
     
  16. pendragon1

    pendragon1 [H]ardness Supreme

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    yipes. maybe some SPs then.

    edit: those vids are with the front panel off too, right?
     
  17. doyll

    doyll Gawd

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    Get better fans. I suspect those are the stock fans and the Dynamic GP-14 is only rated 0.71 mm H2O I suggest something like their new Venturi HP-14 PWM that has 1.94 mm H2O rating. Other fans like be quiet! Silent Wings 3, Thermalright TY-147A Sq and Phanteks PH-F140MP all have much better abiliy to overcome resistance and supply a good flow of air through filters and fancy vent grills. SP140 is way down my list.

    As for spacing the fans into case away from front vents .. all you will do is improve case airblow, and lower case airflow. The front intakes have to bring cool air into case, not re-circulate air already in the case. In case you are intersted, here is a basic guide to case airflow and how to optimize it.

     
    Last edited: Jun 10, 2017
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  18. vergdm

    vergdm n00bie

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    This is excellent, thank you.

    Also OP, couple of JayzTwoCents videos that might help you pick the right fan/fan setup.


     
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  19. pek

    pek prairie dog

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    Maybe get your hand re-calibrated?
     
  20. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    Read the rest of the thread.

    I solved the problem by making my own dust filter out of dryer sheets. The fans move a lot of air but are extremely low pressure. The stock filter is like 1/3 solid plastic and doesn't provide enough airflow. Oddly, the PSU + bottom fan filter is much better, but it doesn't have magnets, so it can't be attached to the front panel.

    Weird design choice by Fractal.
     
    Last edited: Jun 22, 2017
  21. KracknCorn

    KracknCorn n00bie

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    Unless you're putting a radiator on the front, I wouldn't worry about low pressure. If you are, then high pressure fans are what you need.
     
  22. doyll

    doyll Gawd

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    The problem was not the filter framing strips. With no mesh it is probably >90% open area. The front cover venting has only a small fraction as much vent airflow area as the stock filter frame and filter. As I said before the problem is the fans Fractal Design supplies with the case. Even running at full speed they can only just barely overcome the resistance of case venting and filter.
     
  23. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    Just ordered 3x NF-A14 FLX to replace these. Not sure how much of an improvement there will be but I figure it's a good investment.
    Was hoping to get Noctua's new fans, though.
     
  24. doyll

    doyll Gawd

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    NF-A14 FLX will work well.
     
  25. Nephron

    Nephron [H]ard|Gawd

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  26. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    idk if you're serious but using strings, ribbons, and ropes to measure airflow is pretty common in aerodynamics.
     
  27. doyll

    doyll Gawd

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    Not really use to measure airflow, but to check direction of flow. What was fan speed in those tests?
    Airflow will change dramatically with components in and sides side.
     
  28. Kyle_Bennett

    Kyle_Bennett El Chingón Staff Member

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    I heard that some case fans LIKE to be choked. But I wouldn't know anything about that.
     
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  29. Pandur

    Pandur Limp Gawd

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    I know you went away from the idea to use long screws to distance the fans into the case. But I would still like to point out that that would be a bad idea. Because if the front filter is as restrictive as you claim, adding spacers would just give room for the fans to suck air from around them instead. Meaning you're just recycling the air inside your case instead of pulling fresh air through the front filter. And it's better to have a lower flow of fresh air through a filter than just blowing the existing air inside your case around one more time.

    Yes I am exaggerating, of course some fresh air will still be pulled into the case. The point is that spacers would be a bad idea to solve this problem.
     
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  30. Dayaks

    Dayaks [H]ardness Supreme

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  31. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    After a week of waiting, Amazon recalled my order because of the hurricane *yawn*.
     
  32. SvenBent

    SvenBent [H]ard|Gawd

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    man i feel for you. Nobody is probably more hit bad stuff than you not getting your fan due to the hurricane...
     
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  33. doyll

    doyll Gawd

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    Yeah, lots of damage that will take month to rebuild. Lots of people suffering from Harvey and Irma .. and now Jose might be coming. Trap some of it's winds when it goes though and use that to cool your system for the next few years. :D
     
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  34. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    The eye went over my house. Was hoping to pass the time working on the PC until power comes back.

    We also had some bottled water in the order, which thankfully did get here in a separate box.
     
  35. CaptNumbNutz

    CaptNumbNutz Bulls[H]it Master

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    Always use high static pressure fans for intakes. ALWAYS. High CFM does not necessarily mean it is high static pressure.

    With exhaust fans you can use high CFM fans because you have nothing in front or behind the fan obstructing airflow. On intakes, there's a fan grill up front and computer hardware (e.g. heatsink, cables, drives, video card, computer frame, fan filters) near the fan. You need high static pressure fans to continually push/pull the air flow through obstructions instead of one that spins through it at the highest speeds.

    Think of it like trying to haul a trailer with a sports car instead of a truck. With a clear road, a sports car (low pressure fan) can go fast. Put a load on it (fan filter) and suddenly it's slower than a truck meant to haul the load.
     
  36. Gasaraki_

    Gasaraki_ Limp Gawd

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    OP, don't listen to the haters in this thread. They think that the yarn was suppose to be horizontal to equal good airflow.

    Filters do block airflow, I don't think new fans will make a big difference unless the new fans spin over 2000RPM. Those fans in the fractal case are decent fans. I would get faster spinning fans or leave the filter off for best airflow.
     
  37. Mav451

    Mav451 [H]ardness Supreme

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    Yeah I've tested the included Fractal fans in builds for friends/family. They're what you'd expect for included fans - not great.
    There are certain fans that actually scale very well at low RPMs - the Silent Wings 3 specifically (as doyll already mentioned), if silence is your priority.

    [​IMG]

    These are fairly new fans compared to my Phanteks, and being noise-focused, that's what they excel at. You can also compare it directly against the A14 FLX.
    I wouldn't mind picking some up if they were discounted to say $15, down from the usual $20...
     
  38. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    Looking good.
    My PC being off for 4 days killed my mouse apparently, was a PITA posting this lmao.

    [​IMG]
     
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  39. TaintedSquirrel

    TaintedSquirrel [H]ardness Supreme

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    What's more useful, the 3rd (bottom) front in-take or a 3rd fan on the D15?

    Like this:

    [​IMG]
     
  40. pendragon1

    pendragon1 [H]ardness Supreme

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    hmm not sure aboot that. the extra bottom intake will feed the gpu(s) more fresh air. wouldn't be that hard to test.