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  1. #1
    Member Hitbox's Avatar
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    Internal Air Pressure

    Which do you think is better?

    Having a Positive internal air pressure (more air in).
    -or-
    Having a Negative internal air pressure (more air out).


    I bought a Rocketfish and I want to avoid dead-spots.
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  2. #2
    Member CGR's Avatar
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    Well, I like to keep as much dust/cat hair out of my machine as possible, so I try to maintain a slight positive pressure.

    If you are not worried about either, then negative pressure is ok
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  3. #3
    Trailer Chasing Senior Adragontattoo's Avatar
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    positive, my brain doesnt seem to work well in negative terms aka, I couldnt get the Stacker to cool well enough to my tastes without loading it down with High CFM fans.
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  4. #4
    Member VinnyTAMU's Avatar
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    Quote Originally Posted by CGR View Post
    Well, I like to keep as much dust/cat hair out of my machine as possible, so I try to maintain a slight positive pressure.

    If you are not worried about either, then negative pressure is ok
    I agree, I do not know the scientific answer as to why positive pressure in a computer case causes lower dust accumulation, but from my experience it does.

  5. #5
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    Dust accumulation is inevitable, when running fans. The primary function of fans is for cololing, so a slightly negative pressure would be better.
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  6. #6
    I think the official opinion is that low pressure in the case is better for cooling, as there is always air flowing through rather than stagnant air sitting in the case.

    The dust thing is interesting though, i never thought about that.

  7. #7
    Member Hitbox's Avatar
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    Regardless of dust. I'm obsessed enough about it to clean it out every couple of weeks.
    I'm mainly concerned about dead-spots in my case gathering pockets of heat.

    So it's better to have 3 fans pulling out and one pulling in?
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  8. #8
    Member netmask's Avatar
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    IMO it's better to have 3 fans pulling out and 1 pulling in so it creates negative pressure forcing air to move in to cover the empty space of the air that's moving out than sucking it inside along with dust.
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  9. #9
    Quote Originally Posted by Hitbox View Post
    Regardless of dust. I'm obsessed enough about it to clean it out every couple of weeks.
    I'm mainly concerned about dead-spots in my case gathering pockets of heat.

    So it's better to have 3 fans pulling out and one pulling in?
    Yeah, i'd say thats better.

  10. #10
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    If I remember correctly, you'd want negative air pressure for a couple of reasons. For starters, less air means less humidity, although I don't think that plays a drastic role in this case but I guess it plays a role nonetheless. Also, air itself is an insulator; negative air pressure ensures that the heat can radiate more freely and in effect be pulled from the system much quicker. This in part is also due to the fact that when you create a negative pressure environment, you not only lower the amount of air in the case but the amount of energy. Finally, when air does enter to try and balance the pressure differences, it will expand which in turn lowers the air intake's temperature.

    I wrote this up at 1 in the morning so if anything seems amiss or just flat out wrong, just call me on it and I'll be sure to correct myself lol.

  11. #11
    Actually, the temp drop from the lower pressure will be insignificant (unless youre running a vaccum chamber) However, airflow is more turbulent when it is blown in instead of sucked in through rivets and seams, and more parts get cooled off, though YMMV.
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  12. #12
    Member Hitbox's Avatar
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    ------------------------------------------------------------------
    Okay people, thanks for the advice. Negative it is!
    ------------------------------------------------------------------
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  13. #13
    Quote Originally Posted by Hitbox View Post
    ------------------------------------------------------------------
    Okay people, thanks for the advice. Negative it is!
    ------------------------------------------------------------------
    Actually, Id try both, and see what gets you the best results.
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  14. #14
    nightelph's Avatar
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    Quote Originally Posted by Diddyu View Post
    Actually, Id try both, and see what gets you the best results.
    Best advice yet, imo.
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  15. #15
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    Quote Originally Posted by Diddyu View Post
    Actually, Id try both, and see what gets you the best results.
    I've tried both ways & ended up going H2O.


    What ever works best for your situation. YMMV.
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  16. #16
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    I have all intakes (4) with the rad blowing out(3). This is good for two things:

    Dust: The intakes are all filtered, so there should be no dust in the case, as any small gaps in the case will blow air out which will prevent unfiltered air from entering the case.

    More pressure on rad: I'm not sure if this has any effect, but from a logical stand point it does. Basically due to the case's internal pressure, air will naturally try to be pushed through the rad. the added pressure might help in clearing air through the rad. This gets me thinking, because I might actually be able to turn off the rad fans just because I have a positive case pressure as air will flow through it due to the pressure.
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