psu fan position, airflow and possible noise

PSUs: The source of DC power for all components in the PC & often a big noise source.

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psu fan position, airflow and possible noise

Post by PatomaS » Fri Apr 22, 2011 3:10 am

Hi people

I'm about to build a new system, and as usual I'll try to make it as silent as possible, but since it has been some time since I built my last system, I have a few questions which I'm sure you can help me to clarify.

Almost any quality case nowadays has the power supply at the bottom, and almost every PSU has the fan at the bottom, but just a few cases have holes at the bottom, so the air for the PSU has to come from the front and exhaust at the rear. This disposition leaves just a small gap for the the air to circulate between the PSU and the bottom of the case. Isn't this a source for sound and suboptimal air flow?. Also, very few PSU's have fans in the front -> back direction, like the Antec CP series; Isn't this system better at letting the air flow, even with the fan at low speeds?.

For instance, if you use a case with chambers, like the Antec 183, the only real source of fresh air for the PSU is the lower front of the case. In normal configurations, with just one chamber, at least you have the whole space to suck air; may be not too fresh, but ideally not too hot.

There is always the option to put the PSU with the fan on top, but then, how good is this configuration in actual conditions, with very hot graphic cards and hot CPU's?

This question came to my mind thinking about the options for PSU in this next machine, which by the way will be with a 183 case if I can find it in Malaysia, if there is no luck, most probably will be a lian-li pc-b10 or pc-a71f or ... something else, there is not much to choose from here.



Bye the way, I was not sure about the subject of this post, if somebody suggest a better one, I'll change it, so it is more useful.

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Re: psu fan position, airflow and possible noise

Post by themaster1 » Sat Apr 23, 2011 9:15 pm

psu at the bottom/fan on top i've tried in a hot summer day with a GT220, result: it's a no-no, temps get high ~ 50°C .I have a PC-B10.

I have the fan at the bottom now the max temp inside the psu reach 40°C (37-38 is the norm) depending if i put the other fans on or not.

I use this pc daily to watch tv, HD sometimes on 2 monitors..

Now it depends what you have inside that PC-B10 i have 2 500GB seagate barracuda's currently (not counting the OS drive) and these two get insanely hot.If i put and SSD in there i'm sure it'll be fine with psu's fan on top
Hope that help

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Joined: Fri Apr 22, 2011 2:36 am

Re: psu fan position, airflow and possible noise

Post by PatomaS » Sun Apr 24, 2011 8:44 am


Sure it helps. :D

I didn't mention the rest of the pieces since I'm still not sure about all of them, and also because the question about the small gap is not affected by the other pieces. It only seems to be affected if I install a fan or not in the lower chamber.

By the way, I was checking the stores this weekend and it seems that the PSU is going to be a Corsair, no way to find an Antec PSU; about the case, The same lonely 183 box I found two months ago is still there, so I suppose no one likes it, I just hope she sits there quietly for one more month before I can go and get it.

Right now the question still applies, but my options seem to be short, so I will go with what I can find.

Thanks again for the time and help. Any other answer or idea will be very much appreciated.

Bye :D

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