breathing vs. streaming

Enclosures and acoustic damping to help quiet them.

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Riptide
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breathing vs. streaming

Post by Riptide » Tue Nov 02, 2004 12:38 am

Hi

I would like to replace my aging CS601 case with a newer(/better) one. My future config will include some heat producing upgrades like Geforce 6800 or AthlonXP 3200+ but i still want a reasonably silent system.
Different cases seem to feature different ideologies. Looks like good breathing vs. streaming. Cases that breath well (LianLi V-series, CM stacker, ...) feature generous ventialtion openings/holes all over the case. On the other side are cases which seem to approve upon the streaming airflow (Antec 3700,..). They are quite enclosed and feature big intake/outtake fans to generate a distinct path for the air to flow through the case.

As far as I understand.... Good ventilation -> components running less hot -> fans running slower -> quiter ... is the key to a silent system. I'm just wondering which concept realize it more effectively (breathing vs. streaming)? On the 'recommended Cases' page the streaming approch seems to be the way to go. Are those new cases LialLi V-series, CM stacker and the like, just not usefull in terms of noise/cooling ratio?

Denorios
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Post by Denorios » Tue Nov 02, 2004 1:33 am

Hi Riptide, and Welcome to SPCR!

Streaming. Definitely. The trouble with having ventilation holes all over the case, is that it provides numerous paths for sound to get out. :( Not only that, but there is a tendency for multiple air paths to disrupt each other, increasing the case temperature. :x Have a read through this - http://www.short-media.com/review.php?r=230

Though there is still a lot of debate over optimal airflow design, for silencing purposes, the general concensus is that a sealed chassis with air flowing from front bottom to rear top is the most efficient means. Many silencers simply use a single low-speed 120mm fan at the rear, and tidy up their wiring, to prevent it from obstructing the airflow. A fair few of us also use a front 120mm intake fan, but this is more to directly cool suspended hard drives than to reduce the case temperature.

However, you have to remember that part of the price you pay for silence is higher operating temperatures. That is why many of us undervolt our CPU's, and use very large and elaborate heatsinks. :P
"Only a fool expects rational behavior from their fellow human beings. Why do they expect it from a machine that human beings have constructed?"

daba
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Post by daba » Tue Nov 02, 2004 2:41 am

Ehh. my V1000B is pretty silent :)

Ducky
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Post by Ducky » Tue Nov 02, 2004 6:31 am

It's actually slightly more complicated than that:

Streaming is the ideal way to cool things, yes -- but it's also harder, since one would need to actually pay close attention to how the air flows and make sure everything gets some air somewhere.

On the other hand, breathing cases tends to care less about the airflow path, since there is more than one way for air to get to various components. Of course, poorly designed breathing cases would also tend to just have all the air "short-circuit" and get out of the case much too early.

For the purposes of silencing, though, streaming cases would work better, as others have said, since sound is less likely to come out towards the person using the computer.

pangit
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Post by pangit » Tue Nov 02, 2004 8:44 pm

For silencing purposes definitely streaming, so you can direct the airflow exactly where you want it. Even cases like the BQE can be improved by judicial use of duct tape, sealing up around the optical/floppy drive slots etc behind the bezel.

As well as keeping the sound inside the case better, you can do things like cooling hard drives without an intake fan, since all the air flowing into the case can be directed over your hard drive(s). And fewer fans = less noise.

Also you can use intake filtering when you have a sealed case.
[size=75]pangit

[url=http://www.mypage.tsn.cc/pcsilencing]Pangit's PC silencing project "on the (not so) cheap"[/url]
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Zyzzyx
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Post by Zyzzyx » Thu Nov 04, 2004 8:18 pm

I still vote for the best of both worlds. My wallmount system has great breathing, and some decent streaming airflow as well. ;)
[b]Z[/b]
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