Corsair Obsidian 500D air flow

Discussion in 'Cases & Case Modding' started by Ryom, Dec 2, 2018.

  1. Ryom

    Ryom [H]ard|Gawd

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    I recently moved cases from a Lian-Li V-1000 to a Corsair Obsidian 500D. There were a few reviews that had stated it had bad airflow dynamics but I think it's actually pretty decent and the noise floor is quite low.

    I have a 120mm Corsair ML-120pro on the back, two ML-140s on the top, and two ML-140s on the front. The HSF is a Coolermaster 212 EVO. I flipped the upper front fan around after I took this pic, so the arrows are correct. I'm wondering if using three 120s in the front with the two upper flowing out and the bottom flowing in would be better... the gap is bugging me :)

    The bottom fan brings cool air in for the video card which should be exhausting most of the hot air into the current warm air path in the upper half of the case (it's not a blower style cooler).

    Corsair Obsidian 500D Air Flow diagram 1 of 2.jpg

    Corsair Obsidian 500D Air Flow diagram 2 of 2.jpg

    HWinfo64_Corsair-500D.png
     
    Last edited: Dec 2, 2018
  2. TLoki

    TLoki n00b

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    Would that setup creates alot of negative pressure = more dust?
     
  3. Fritzz

    Fritzz Gawd

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    Being that the 500D has a panel in front of the front fans, I would think any warm air exhausted by the top(front) fan is just being pulled back in with the bottom(front). IMO your current setup would introduce a lot of turbulence, both internally and externally.

    You talk about a bottom fan, but I don't see a fan, nor did you list one in your first paragraph. Are you talking about the PSU? If so most if not all PSUs pull air in and exhaust it out the back.

    If it were my case I would run 3 fans up front as intake, flip your CPU cooler around to push the air rearward, change the back to exhaust and the top fans leave as exhaust. I would either run all the exhaust at lower RPMs or kick up the RPMs on the 3 intakes, end result would be positive pressure which is better for dust reduction. If you wanted more fresh air for your CPU you could run the rear as an intake, but for me I prefer a front to back airflow.
     
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  4. Ryom

    Ryom [H]ard|Gawd

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    That's not a bad setup either! But I was referencing the bottom fan on the front of the case which is an intake. The PSU is compartmentalized separately from the rest of the case airflow and should be largely irrelevant. I have a custom fan profile setup so that the case should be kept at a positive pressure (the exhaust fans are set to half the speed of intakes), and finally the case has dust filters anyway (including under the PSU). The rear fan flowing directly into the CPU fan brings in cool exterior air which should make the CPU cooler more efficient than pulling from the opposite side due to the GFX card dumping enormous amounts of waste heat directly into the case. So that fresh stream from the rear port is pretty crucial by my reckoning. If I had a blower style GPU I'd probably do it your way since the interior wouldn't be getting heat soaked by the GPU.

    So this setup is largely to mitigate the effects of a non-blower GPU dumping heat into the case and this is the best way to cycle that heat out and keep the CPU and GPU chilly that I could devise. That front fan at the bottom intakes cold air which should be drawn up into the GPU. The rear fan intakes cold air directly into the CPU HSF. Both the HSF and GPU should be dumping their heat into the top front quarter of the case which is where all of the exhaust stream is.

    I'm kind of wanting to run a smoke pattern test to see how the air currents look actually :)

    It's possible that the front panel is directing some air down towards the lower intake fan, but the air flowing in that bottom fan feels very noticeably cooler so I'm thinking that the two topmost fans are doing the bulk of heat removal.
     
    Last edited: Dec 3, 2018
  5. Devil Inc

    Devil Inc n00b

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    I'm building a dual 360mm loop in this case currently. My plan is to pull air in through the front and out the top. The PSU will be pulling in from the bottom and out the back. The case will be on a tabletop, so I'm not worried too much about heat cycling the PSU.

    I'm contemplating making a block-off for the rear fan hole, in order to maintain a balance of flow within the case.
     
  6. Ryom

    Ryom [H]ard|Gawd

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    My thought would be to run the rear port as in intake to help keep the case at positive pressure, which should also help the radiator fans maintain good static pressure numbers. Plus that also brings in some cool air that hasn't passed through a radiator which may keep your RAM and VRMs a little cooler.
     
  7. Devil Inc

    Devil Inc n00b

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    That's an idea for keeping the case at a slight positive pressure.
     
  8. Ryom

    Ryom [H]ard|Gawd

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    I've been toying with the idea of rotating my HSF 90ยบ to point the exhaust airflow directly at the backplate of the GFX card, along with flipping the rearmost top case fan to intake so it blows directly into the HSF like the rear port is currently doing in my first post. I'd probably add a fan to the far side of the heatsink as a pull fan so it's right there at the backplate. The air will be warm, but I think that strong airflow across the back of the GFX card could improve thermals regardless. The CPU typically runs cooler than the GPU and the HSF exhaust is even cooler than that. I just wish the 212 EVO wasn't such a huge pain in the ass to seat. :)