"Front case fan" recirculates hot air?

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eddieck
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"Front case fan" recirculates hot air?

Post by eddieck » Sun Feb 28, 2010 11:04 am

I came across a bit on EndPCNoise's site (was looking for the Nexus fans since PTS is out of Yates) saying "front case fans" (presumably intake fans?) recirculate hot air rather than introduce new air. That seems strange to me since everyone here is using intake fans, and also, ECPN's own 22 dB gaming system has a fan in the hard drive vent which I assume would be an intake fan. What's the truth on this?

Das_Saunamies
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Post by Das_Saunamies » Sun Feb 28, 2010 1:40 pm

Sounds like bollocks. If the fans have access to cool, room-temperature air and are sufficiently cut off from the air inside the case, they'll draw in cool air. Wish this point about recirculation was elaborated a bit further - maybe it was some individual case (literally)?

I've tried an all-exhaust case fan setup with two Antec cases (Sonata II and P182), neither worked as well as a setup with both intake and exhaust fans. "Front" fans have most notably helped with RAM stability and HDD temperatures.

For example: my 3 HDDs got up to 60'C in this P182 and the oldest started having issues (increased access time due to errors, corruption). This was due to the Asus mobo cutting off power (stupid, stupid QFan, useless FanXpert) to the fan, leaving them to be cooled by what little negative pressure the Corsair PSU's exhaust would generate. With the 800 RPM fan going the HDDs are snappy and happy at 30-35'C - and this isn't even a proper intake fan!

eddieck
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Post by eddieck » Sun Feb 28, 2010 2:12 pm

I can't post links properly (not enough posts) but here's where I found that

endpcnoise dot com/cgi-bin/e/silentpc_cooling.html?id=kaHyFSx8

Das_Saunamies
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Post by Das_Saunamies » Sun Feb 28, 2010 2:21 pm

And on further analysis of their site, we find that they are quoting an external source, who are quoting "some extreme situations". This could translate to "in the 5% of cases that consisted of total idiots who had built their own cooling, a front fan recirculated hot air". The original source is really vague about it, EPCN makes it sound like firm fact and the way you quoted it made it sound like absolute truth. See how chain-quoting ruins the original study's perhaps-valid findings? :lol:

EndPCNoise should know better than go spouting something like "Don't Use a Front Case Fan". Guess it's up to the reader's healthy criticism again to figure the text's worth out.

Edit: For ultimate silence, less really is more, I agree to that - but it takes more than just stripping fans to achieve. And claiming a front intake fan doesn't do much is just utter bull.

xan_user
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Post by xan_user » Sun Feb 28, 2010 3:03 pm

If one blocks of the front half of the case from the back half with a wall of ribbon cables, then a front fan only circulates hot air...But we know better than that, dont we?

eddieck
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Post by eddieck » Sun Feb 28, 2010 3:54 pm

Yeah. I knew it didn't sound right, but EPCN's one of SPCR's system partners so I figured they might know a little something. Thanks guys :)

datapappan
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Post by datapappan » Tue Mar 23, 2010 10:41 pm

It's not just any external source, its AMD. It's an old PDF for Athlons (AMD Athlon System Cooling Guidelines).

Here's what it says:
A front cooling fan does not seem to be essential. In fact, in some extreme situations, testing showed these
fans to be recirculating hot air rather than introducing cool air.
(my italics)

So, the front case fan will in some, undefined, extreme cases recirculate hot air, hmmm.... (The PDF points to an in-depth analysis, but the link didn't work in my PDF reader)

Side note: the PDF also proposes dust filters, on intake AND outlets. Go figure.

/ d

Das_Saunamies
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Post by Das_Saunamies » Tue Mar 23, 2010 11:08 pm

I left out the precise source because it was irrelevant to my argument, and anyone interested could read up on it.

vortex222
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Post by vortex222 » Sun Mar 28, 2010 9:51 pm

im not big on front case fans myself, but i do make sure the case is going to path air properly when the lid is on. Putting my hand on the front vents of my 180 shows me there is allot of air being sucked in the front, but i have most of the extra vent holes on the back and top of the case sealed off so it has no choice but to come in the front.

a front case fan would perhaps help direct some airflow more across the video cards fan, but not really certain, nothing in my case really has problems staying cool enough, including my scsi drives

ronrem
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Post by ronrem » Tue Apr 20, 2010 1:47 am

vortex222 wrote:im not big on front case fans myself, but i do make sure the case is going to path air properly when the lid is on. Putting my hand on the front vents of my 180 shows me there is allot of air being sucked in the front, but i have most of the extra vent holes on the back and top of the case sealed off so it has no choice but to come in the front.

a front case fan would perhaps help direct some airflow more across the video cards fan, but not really certain, nothing in my case really has problems staying cool enough, including my scsi drives
A front fan is typically much closer to your EAR than a rear or BOTTOM fan.
If the EXHAUST pulls air out...air will ENTER....with or without a front fan. The trick is to THINK out the path and do a few mods so the air takes the path you want it to. Many cases really are not designed for the best of quiet operation,are aimed at the overclocked gamer with 4 fans at 2000 rpm each

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