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Positive Pressure? - Page 2

post #11 of 17
10/26/12 at 1:28am
I like the quote but your case will not get diarrhea or become constipated. rolleyes.gif

If your intake fans can trying to push more cfm than exhaust fans cfm can pull out, the intake fans will not be able to push as much air and the exhaust fans will end up flowing more then their rated cfm.. and air will leak any other places that can leak air out.... and if your exhaust fans are trying to pull out more cfm than intake fans are pushing in the exhaust cfm will be reduced and intake cfm will increase to equal the cfm flow.. and suck air into case from any other places that leak air in.

But I do like the diarrhea / constipation analogy. thumb.gif
Edited by doyll - 10/26/12 at 2:00am
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post #12 of 17
10/26/12 at 7:51am
i was going to use those terms, but some still may not know what those terms mean...

airdeano
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post #13 of 17
10/26/12 at 9:16am
I know.
And I know you know
And you know I know you know biggrin.gif
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post #14 of 17
10/26/12 at 11:39pm
i didn't know that?!?!

airdeano
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post #15 of 17
10/27/12 at 8:49pm
  • ehume
  • AirGoesWhere you push it

I believe in positive flow, not positive pressure. So I remove all rear slot covers. I also remove the rear grill. So I have only filtered intake fans, none used for exhaust. They all operate at low rpm, so I have a quiet case. Because there is no obstruction, no pressure can build up.

 

For some fun, look at item 2 in my sig. I had either removed or unplugged all case fans, just let the fans on the Megahalems run. With no outlet obstruction the Mega was able to suck in air through all the windows of the case. Even with a wide-open fan window right above the Mega, air was being sucked through the lower front front fan (the fan itself was unpowered). THAT is what you can get when you cut out your rear grill.

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post #16 of 17
10/28/12 at 8:51am
It's kinda a grey area. The paper staying against side vent is the result of more outside pressure than inside pressure. Not much, but enough to hold the paper against it. wink.gif I know it's just good airflow with no restriction on exhaust a causing it, but pressure differential is what is holding the paper in place. wink.gif

And I cut out my vents wherever possible too, same as you. thumb.gif
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post #17 of 17
11/2/12 at 1:00am
I'd say your plan is fine.

You can mount the second pull fan on the HSF but don't expect miracles, probably 1 - 2c.

I would remove one of the HDD caddies, if you can. Mount both SSD and HDD on the lower caddy cooled by the lower front fan.

The top front fan seem like it will help both GPU and CPU get some fresh air..

As for top fans there's the usual, mount intake front-top fan, block the other rear-top intakes.

I would also try something not very conventional. Mount the HSF facing downwards and top fans intake. This way the CPU will get fresh air from the top and blow some air over the top of the GPU. The GPU is always hotter so will still benefit from the "warm" HSF air flow and on top of the air pressure will help it cool further.
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