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Negative Pressure - no intake fans

Discussion in 'Project Logs' started by Kammster, May 20, 2007.

  1. Kammster New Member

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    Location:
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    How it works:
    CPU : intake funnel + amd fan + 80mm exhaust (restricted vent holes) (31 deg idle)
    Gfx : side panel intake vents + zalman + 60mm exhaust (39 deg idle)
    PSu exhasut + intake vents in front of hardrive (32 deg idle)
    chiptset 34deg (idle)



    I just wanted to exhuast the hot air from the case before it statred to effect the generic psu, so i cut a hole in the thin sheet metal, and installed a 60mm fan for testing and i got a big surprise!
    not only did hot air vent out faster but the other components got as much as 5 deg cooler.

    before chipset hit: 43 deg under gfx card heat
    after : 38 deg / 39 deg(silent)

    the temp drop was also on the cpu load temp 42 to 39
    but the gfx card was best; before my max temp never varied with clock frequency always 63 deg.
    now 300:350 (barely 54 deg); 415:496 (59/60 deg)


    my theory is: basic fliud mechanics volume in = volume out. the exhaust fans pull so much air out of the case that they not only pull in air thru the vents but also cause air in the case (hot air) to move in currents to the exhausts(2+psu).


    i am 60mm(25mm thick) 12v@0.12V thta i got from a car parts store.
    also tried a spare fan from a mircofin socket A cooler:
    dynatron mircofin (15mm thick) 12v@0.25v top speed 5200 rpm (loud -48 db), i forgot the temps because it was too loud, @silent(5v) was same.
     

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    Last edited: May 22, 2007
  2. ex_reven New Member

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    The only downfall is you get more dust in your case :)
     
  3. Kammster New Member

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    quick update

    there is dust everywhere, any place than air can move there is dust, behind the hard drive the front grill thing has dust spikes like a fan blow it there.

    had to take out the 80mm fan for another case, put in a 92mm and it really kicks
    temps gpu @ 400:425 57core:45mem
    and the temp falls fast when the load stops.

    vibration from the fan on side panel was bad but got a idea from a generator room and used rubber strips for patching bicycles to dampen the noise.
     

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  4. [I.R.A]_FBi

    [I.R.A]_FBi

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    actually positive pressure is more desired than negative ...
     
  5. kwchang007

    kwchang007 New Member

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    really? so air just starts flowing out type stuff?

    EDIT: I always though balanced pressure was the best?
     
  6. Zeratul_uy

    Zeratul_uy New Member

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    I got intake front, exhaust rear... That's the best setup i've tryed so far and works preety well.

    Let´s see if i find some pic with my temps before my mobo dies...
     
  7. Zeratul_uy

    Zeratul_uy New Member

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    Found it, Everest Temps right there, and Shitty BG with my name xD
    [​IMG]

    Black = HD
    Blue = GPU
    Brown = CPU
    Green = Mobo

    And those aren't my best temps :p coz that ones was after running the bench xD
    Best Idle were 25 HD, 20 GPU, 26 CPU and 19 Mobo...
    Believe it or not :D

    See'yas!
     
  8. kwchang007

    kwchang007 New Member

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    i believe you. my friend is running his e6600 with stock cooling and thermal paste, and it idles around 28 when it was ~65 F. he has one intake on the front, one intake (cpu sleeve thing) one side, one exhust on side, one exhust on back, and the psu. very cool system, you can feel the room heat up (i guess that's not a good thing, lol) sounds kinda like a turbine when it's running though....in a good sort of way.
     
  9. Kursah

    Kursah

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    From my experience and a few of my IT buddies, they find a close match to a 1:1 ratio serves well, you have your exhausts up high and rear, intakes low and front, it helps replenish the exuasted hot air faster with cooler air than negative, since you have fans pumping air in. Posotive I believe would be more intake than exhaust, which is the least effecient method, it will not be able to remove the heat as quickly, which is the goal with OC'd PCs. If you have more air moving in the case, but not exhuasting hot air efficiently, you're trying to cool your components with hot air, doesn't make much sense, but posotive is supposedly the best way to keep dust to a minimum. I'd rather clean my PC more often and get more effective cooling. I may be backwards on those, but that's how I understood it.

    Also, IRA, you gonna fill out your system specs in your User CP so we can see whatcha got running? I'm kind of curious, because it seems like you have some OC experience. Let's see what you have.
     
  10. [I.R.A]_FBi

    [I.R.A]_FBi

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    pc is currently down .. waiting on a vid card .. got a E6400 ... 2 gigs o ram, ABit AB9Pro, stock intel cooler for now
     
  11. Kursah

    Kursah

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    Nice, keep us posted on how it turns out!
     
  12. Zeratul_uy

    Zeratul_uy New Member

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    Hahaha, mine is not sooo noisy, tested just all the fans, with the case empty :)cry: there is nothing in there) at 5 am, when the house is ultra silent and the only fan that made a noise, was lubricated and now is not noisy xD Ultra Silent Zera Cooling lol \o/
     
  13. kwchang007

    kwchang007 New Member

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    lucky you, his sounds like a turbine when he starts it up pheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeewwwwwww but it does a good job at keeping it cool. and if he bought a fan controler, im sure he could leave them all at low and still get really good idle temps.
     
  14. Zeratul_uy

    Zeratul_uy New Member

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    Hahahaha, he need limits on those rotations xD hahaha the "phewww" thing was really funny hahaha
     
  15. kwchang007

    kwchang007 New Member

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    lol thank you. he sort of does....i mean he's usally blasting music, or playing his guitar really loud....so the pheww isn't noticable. actually now that i try and remember, once it's running, you don't really notice it, it's just when you start it and it goes phewww, here's the case
     
  16. Zeratul_uy

    Zeratul_uy New Member

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    Looks really sexy, mine is self-made hehe i cutted, drilled and tweaked myself... I'll upload some pics :D

    And for the noise thing, my Heatsink used to do tons of noise too lol it wasn't "phewww" it was like "hhhhhhhhhhhhheeeeeeeeee" and was really annoying coz I couldn't hear at low volume xD and when the night is silent, arround 3~5 hs am, it was really unbearable... So I've reduced the RPM's of it and it worked still at good temps and ofc with much less noise... :D
    (Taken with a webcam, my digicam is broken)
    Before painting and mounting of the side Metacrylate (dun remember if it is spelled right) panel
    [​IMG]

    After painting and mounting of the side Metacrylate pannel and before the lights and side 120 mm x 120 mm fans \o/
    Front
    [​IMG]

    Rear
    [​IMG]

    Metacrylate side
    [​IMG]

    And the other side (nothing special on it at the pic, made an AMD logo with vinyl on it)
    [​IMG]

    When I got my digicam working I'll post it on rate my case, now it's finished xD
     
  17. kwchang007

    kwchang007 New Member

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    yeah, it's sexy, just no side panel, and i don't think he wants to mod it (he's not even overclocking :wtf:). you have no idea how many cases we had to go through....it'd be like ....too blue....not blue enough....not enough fans.....to white (some weird stuff) but now....sexiness. wow, nice case. id defiantly give you a good rating (as long as you have good cable mangment, etc, the case is nice though)
     
  18. Zeratul_uy

    Zeratul_uy New Member

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    Pics are way crappy, the cables were tied and moved away to let space for airflow, but now (before I taked all off) they were covered with a green (dunno how to say it lol) hmm thing xD and some green lights... It was nice... :D
     
  19. kwchang007

    kwchang007 New Member

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    green!!! :D a much different color than the normal blue.....i think i like green.....hmmm...actually, i think i like no lights and a slient computer so i can sleep with it on, of course since slient is not possible....LIGHT IT UP!
     
  20. Zeratul_uy

    Zeratul_uy New Member

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    It was everything black (Mate? it's ok?) but painted the inside of fluo green, and with the lights it rox ^^
    Personally, I love black mate and fluo green \o/
     
  21. kwchang007

    kwchang007 New Member

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    lol i meant lights when i said green. just cause...well....idk maybe it's because our grass is dying. i think it'd be intresting to see something with a UV light, are there any case mods here that have a UV lighting?
     
  22. Zeratul_uy

    Zeratul_uy New Member

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    I could change the green lights by UV lights... If you rate me 10/10!! haha
    Already though it but preffered green ones, I can give a try :D
     
  23. [I.R.A]_FBi

    [I.R.A]_FBi

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    from the Ideal Gas Law , pV=nRT. Rearranging we get n=(pV)/(RT), so increasing the pressure increases the number of air molecules to conduct away heat.

    im just theorizing still ...

    Bless
     
  24. Kursah

    Kursah

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    I tested the positive air induction method, my temps increased by quite a few degrees C. The Ideal Gas Law makes sense, but at least in my application using More CFM Out than In (not by too much, based on est. fan airflow from specs) was the coolest airflow based solution. But if a few people try removing their case exhaust fan and only using PSU fan for exhaust, leaving intake installed and running, compare to current temps. That's the best way to verify is to try it out and see results with your own eyes.

    IRA, you have any goals set for OC-ing that 6400?
     
  25. [I.R.A]_FBi

    [I.R.A]_FBi

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    yeah, i dont want to burn it up, lol. i live ina tropical country so 2.8 - 3.0 will do ... or 3.2 when im going to go crazy. i got a freezer 7 on the way still
     

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