PSU Fan Setup

[Mr5oh]

So anyways I bought a generic 480 watt power supply last week to go with my GeForce 6800.

The fan setup seems weird. One large 92mm fan sucks air into the PSU (Normal), then there is a fan on the back of the power supply (inside the case) that blows the hot PSU air into the case. I don't understand this, since all the other PSU I have ever had, blow the hot air outside of the case.

Is this like this for a reason, or should I turn the fan around?

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[Cybercraig]

Turn the fan around. An obvious mistake at the factory. I would RMA that dog if you can. Who knows what other mistakes they made. Wrong resistors, wrong heatsink? Who knows!

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[Crashman]

Wow, you must have misread what he said! He said the power supply has an intake fan and an exhaust fan. I've seen those. The intake fan is inside the case and pulls hot air out of the case. The exhaust fan pulls hot air out of the power supply. As in, push-pull. I don't know why they do that, but both fans are blowing in the same direction: From inside the case to outside the case.

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[Crashman]

This is found on some power supplies, my only guess is that the doubling of fans makes them spin more freely increasing flow.

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[randy66]

there still should be an exhaust fan blowing out,
are you saying exhaust is blowing into the case ??
no exhaust blowing out from rear at all ??

 

[Mr5oh]

Thanks, I figured it was probably correct, but seems like blowing hot air inside the case is a DUMB idea. Anyways I put an exhaust fan in the top of my case to help get rid of the hot air.

Do you think I would disrupt airflow if, I turned the fan on the back around, and put another fan on the outside of the case. So basically I have two fans, one on each side blowing outside the case, plus the 92mm sucking air in?

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[Mr5oh]

are you saying exhaust is blowing into the case ??

Yeap, all that hot power supply air blows right inside my case.

The engineer who thought this up needs to be, (In the words of Ned_Flanders), shot, killed, raped.

That was just a great quote from Ned.

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[Crashman]

OOPS, looks like I also misread your post. So the intake on the PSU is on the outside, and the exhaust is on the inside? That's kind of stupid. Manfacturers used to do that on power supplies made for towers that had no cooling fan, to blow warm air across passive heatsinks (to remove the hotter air surrounding them) but it makes no sense on modern systems!

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[Mr5oh]

I was wondering, not really worried about the warranty on my $20 powmax anyways, so I am turning the fans around, and probably add another fan in the back.

Can't see why on earth they would make such a setup. Well thats what I get for $20.

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[Worf101]

My Antec Neopower 480 has one fan as well and it "blows" down into the case as well, or so I thought. This fan is quite large 120 mm., and it rarely goes above 1,200 rpm. I thought as you did "chite why is this thing blowing hot air INTO my case". But then I looked at the blades on the fan and their "pitch". I applied what I'd learned about "prop pitch" from dealing Flight Sims like "IL2 Surmovik" and decided to do a little testing.

Blowing smoke (no jokes now) across the PSU I found that the blades on the Neopower are pitched so as to draw air/smoke from the case, through the PSU and out it's back grates. I don't imagine this to be true, I watched it do it's work. So, although your PSU may be similarly designed do NOT assume it's blowing hot air "in".

My machine is running at 32* Celcius in mid summer at idle. 54* Celcius under full load. That's running "CoolnQuiet" of course. The temp drops about 18* in 2 minutes when I stop playing.

Da Worfster

If you don't stand for something, you'll fall for anything.

 

[Mr5oh]

I think you are referring to the fan on the bottom, mine has a 120mm fan there too which sucks hot air into the power supply, but then a fan on the back of the power supply most defaintly blows the hot air into the case, I did the same smoke test you did. I'm gonna flip the fan, its obvisuly not working the way it should.

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[Cybercraig]

You are asking for it with a POWMAX. It's gonna go "POW" on you sooner than later. NewEgg has the 420 TT Pure Power for $37.00 shipped. RMA that thing!

Abit IS7 - 2.8C @ 3.5ghz - Mushkin PC4000 (2 X 512) - Sapphire 9800Pro - TT 420 watt Pure Power
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