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Case fan and power supply

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Last response: in Components
March 8, 2012 4:55:40 PM

Hi every one

I have a couple question about case fan and power supply

the case fan power connection will connect to the power supply or on board power fan which way is better?

Power Supply OCZ 850W mounting in cooler master haf
I got a little confuse about power supply fan face up or face down?

Face Down at the bottom of the case for suck the cool air from out side to in side of the power supply to keep the power supply cooler. Is that right.

Face up at the bottom of the case for sucking the hot air in side of the case out ? is that correct.

which way is better.


More about : case fan power supply

a c 77 ) Power supply
March 8, 2012 5:06:28 PM

for the fan question; it depends on the on the case fan. some fans have 3 pin connectors that you can connect to the mobo. some fans have molex connectors, speed reduction connectors, or 3-pin to molex adapters. all of those can be connected to the PSU. as long as the fan spins then you connected it right.

for your PSU; it makes little difference. i've tested several PSU in a few cases both fan side up and down, i saw no difference. the real difference is dust. most cases have a filter on the bottom of the case or you can purchase a magnetic filter to place on top of the PSU. i would position your PSU so it can avoid getting dust inside of it.

Best solution

a c 1669 ) Power supply
March 8, 2012 5:22:26 PM

The power supply's job is not to cool your case.

The PSU's intake fan should be taking cooler air from outside of the case to cool itself and then exhausting it out the back. That is the reason why the case designer/manufacturer has put the vent on the bottom of the case underneath the PSU for that express purpose.
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March 9, 2012 2:58:09 AM

Best answer selected by jimmyt58.
March 9, 2012 2:58:53 AM

Thank you every one

I think the case fan connect to mainboard it will be control by motherboard tempeture if system got to hot the fan RPM will speed up is that right?
if you connect it to power supply, the fan will run full speed all time.
how can we control the fan at the speed we want it to run?
a c 77 ) Power supply
March 9, 2012 10:21:06 AM

jimmyt58 said:
Thank you every one

I think the case fan connect to mainboard it will be control by motherboard tempeture if system got to hot the fan RPM will speed up is that right?

only if it's a 4-pin PMW fan hooked up to a 4-pin fan connector will the mobo control fan speed. you can also control fan speed through fan controllers & connectors. otherwise it will run at full speed

Ko888 though is incorrect in his statement. PC cases have placed PSU on top of the case for years with the fan pulling air in and then out the case. antec had some of the coolest cases (temp wise) around, including the 902 and 1200, none gave you the option to run the PSU fan side down. the whole fan side down thing is more perception then reality when it comes to cooling. its best feature is to keep dust out of your PSU which does more for cooling then having a PSU fan up, down or the unit on top of the PC.

* in fact in the latest PC Gamer build magazine, they use a corsair TX850 v2 PSU and cooler master HAF X case for their gaming build. they state "ensure the PSU fan faces up" and display the image as such even though you have the option to place it fan side down. i don't agree or disagree with that option (as stated above) its up to the user and their personal taste.