psu fan replacement

[dasos]

I recently replaced a fanless psu with Corsair CX 430W, which has an 120mm fan (thermally controlled).

Because fan is noisy for my taste(its the only noise source in my system), I replaced it with a Scythe slipstream 500rpm, which is completely noiseless.

I guess that the new fan push less air than the original one. Could this be a problem? Could it harm the psu or affect its performance?

Another question is,
are there 'exhaust' and 'intake' fans by default, or fans work in any case according the position we mount them?

 

[wolfeking]

Okay, the first question is kind of complicated. RPM does not equate to cooling performance when comparing different designs to one another. You need to get the CFM rating of both fans to be sure.

A hot PSU will be less efficient, and will drop the amount of Amps/Watts that it can produce.

There are fans that work better for one or the other, but technically not. You can use any fan for either purpose. Just make sure that you are putting it in the right way round for the airflow direction you wish to have.

 

[FuryRosewood]

uh...maybe? if it is ran closer to its max output it may have issues. Though having opened it, the warranty is now out the window

 

[dasos]

Okay, the first question is kind of complicated. RPM does not equate to cooling performance when comparing different designs to one another. You need to get the CFM rating of both fans to be sure.

I m sure, I dont doubt for that, they are different fans and the one I installed pushes less air, just 24cfm.

The original is this [0.30A]
The one I installed is this [0.07A]

Scythe fan is completely noiseless because its only 500rpm.

A hot PSU will be less efficient, and will drop the amount of Amps/Watts that it can produce.

"Less efficient" you mean that pulls more power from the wall than use for the components?
My psu wont easily gets hot, I dont use to play 'heavy' games.
I have a x4 960T(TDP 95W) which most of the time run at 0.9V, a 9800gt green(no extra pin connector), a pci_xpress soundcard, two sticks of DDR3 and I connect just a dvd drive and an SSD.
If the damage is only some Watts dropping then I guess I'm ok, because I need less than 430W.

There are fans that work better for one or the other, but technically not. You can use any fan for either purpose.

That was not clear enough, if there are fans that work better as intake(or exhaust), then why not buy a fan with such indication?
But psu's fans are always intake?

 

[Virssagòn]

wrong section?

 

[jonnyp11]

That was not clear enough, if there are fans that work better as intake(or exhaust), then why not buy a fan with such indication?
But psu's fans are always intake?

Not sure about the first part, doubt it will be much of a difference, but the psu fan is always intake so it is pulling cool air through the power supply.

 

[dasos]

Not sure about the first part, doubt it will be much of a difference, but the psu fan is always intake so it is pulling cool air through the power supply.

That means its better psu be in the base with fan looking down, where holes exist?
So far I had fanless psu which was located up. So now u think its better to buy a case with psu located down?

 

[jonnyp11]

bottom is probably the best place so it can stay cool.

 

[wolfeking]

That was not clear enough, if there are fans that work better as intake(or exhaust), then why not buy a fan with such indication?
But psu's fans are always intake?

It is not as simple as intake or exhaust though. You have to take a look at the case to tell what it needs where. Exhaust fans are better with High CFM low static pressure fans. intake it depends on what the location of the fan is. if it is right on the Heatsink, a Radiator, or any component for that matter (HDDs, PSUs, etc.) then you need a High Static Pressure fan. If it is just an intake with no component within about 3" of the fan, then a regular fan is fine.

 

[StrangleHold]

Of course it wont cool as good. The OEM fan would put out 46 CFM at full load. The new one is only a 24.5 CFM.

 

[dasos]

Of course it wont cool as good. The OEM fan would put out 46 CFM at full load. The new one is only a 24.5 CFM.

Yes, thats what I said too. Point is what could be the effect of this change.
Can you read post#4 and give your opinion?
(link says that oem fan goes up to 54cfm)

 

[Okedokey]

Look as others have pointed out, efficiency doesn't mean reduction in the PSU's ability to provide power, it will just use more from the wall.

THe fan is lower rated, but the original is designed with cheap case and poor ventilation in mind. If you have a case that allows the PSU to draw air directly from outside the case, you'll be fine.

Just make sure you check the exhaust air when gaming etc. If it gets too hot, you're probably slowly killing the PSU.

 

[dasos]

Look as others have pointed out, efficiency doesn't mean reduction in the PSU's ability to provide power, it will just use more from the wall.

Only me said that, no any "others"
So, I ll have less psu effiency?
Bigger electricity bill?

THe fan is lower rated, but the original is designed with cheap case and poor ventilation in mind.

The original fan has poor ventilation?...
That sounds good, but the one I installed has only 24cfm, while the oem has a scale 24-54cfm.

I guess that the more rpm doesnt necessarily mean the more cfm. For examble this oem fan, as link says, gives in 860rpm the same cfm scythe fan gives in 500rpm.

The major question is, do I need psu fan work up to 54cfm? Looking to my system and my usage, I guess no. That means I can replace it with Scythe without any fallout?

If you have a case that allows the PSU to draw air directly from outside the case, you'll be fine
Just make sure you check the exhaust air when gaming etc. If it gets too hot, you're probably slowly killing the PSU.

So far I have psu located up. Cpu has a fanless Scythe Ninja 3 heatsink and with side open the temp of cpu is 20-35oC.
I guess that I need to buy a case with psu located down. But a case as I want it will cost me too much, can I just install another scythe fan in the cpu?

 

[StrangleHold]

The original fan has poor ventilation?...
That sounds good, but the one I installed has only 24cfm, while the oem has a scale 24-54cfm.

I guess that the more rpm doesnt necessarily mean the more cfm. For examble this oem fan, as link says, gives in 860rpm the same cfm scythe fan gives in 500rpm.

No, he meant the fan setup in the corsair can do well for cases that have poor ventilation. The fan you replaced it with only has around half the air flow.

 

[dasos]

No, he meant the fan setup in the corsair can do well for cases that have poor ventilation. The fan you replaced it with only has around half the air flow.

What means "The fan is lower rated" ?

The oem fan works in a scale 24-54cfm, or 21-46cfm according newer testings.
The fan I replaced has a steady airflow(24,5).
So point is, do I need the maximum airflow which oem fan gives?

I guess the oem fan is cheap quality (as usually happens) and cant be compared with the scythe one.
Looking the specs of them, the oem fan needs 860rpm to give 21cfm, while the scythe fan needs 500rpm to give 24cfm.

If a user mounts psu in the base of case, psu will receive fresh air form outside and there will be no matter of poor ventilation, right?
So I m afraid I have to get a new case with psu located down:/

 

[StrangleHold]

Your power supply has a thermally controlled fan. A low pull the fan doesn't not turn at all. With a little pull it runs at half speed. When its being fully loaded the fan runs at full speed. Its controlled by the power supply. The fan you replaced it with only has half the CFM that the fan took out. Your fan now will only have 24.5 CFM when the power supply is under full load, not all the time.

 

[dasos]

Your power supply has a thermally controlled fan. A low pull the fan doesn't not turn at all.

Yes I already said its thermally controlled but not 'not turn at all'. Its always on (there are some Corsair models with 'not turn at all' but I avoided them after I read some bad feedbacks).

Your fan now will only have 24.5 CFM when the power supply is under full load, not all the time.

Not exactly... My fan now is always 500rpm. I watch it real time with SpeedFan and AIDA64.
Fan now is not controlled by the psu, it is connected in mobo