PSU fan direction

[mjrtoo]

I'm using a Thermaltake ToughPower 750w in a Lian Li PC-A10. The power supply mounts at the bottom of the case with the exhaust fan blowing directly at the case side. The problem is, the heat from the PSU gathers at this location and it seems that the thermal sensor kicks the fan into high almost all the time. As soon as I remove the case side, I can hear the RPM of the fan instantly drop to 'normal' levels.

If you were me, would you consider reversing the flow of air in the PSU so that it exhausts out the back of the PSU rather than into the case as is currently happening? I would assume that with the design of the case you would want to exhaust the PSU heat out the back...

Have any of you done this with a Thermaltake PSU?

TIA

 

[PurdueRy]

http://img45.imageshack.us/img45/46/psuinstallif2.jpg

Seems like if you mount it this way it should have plenty of room.

 

[John]

The TT TP750 140mm fan is sucking air from within the case and exhausting it out the back. Reverse the entire psu per the link in PurdueRy's post.

 

[mjrtoo]

I'll, give that a shot, but if I ever decide to go with two power supplies it will be an issue.

 

[JEDIYoda]

The fan is that way in the PSU for a reason....also you will void the warranty if you reverse the fan!!

 

[mjrtoo]

Nothing seems to line up when trying to mount it that way....The power switch is in the wrong location for the slot and none of the mounting holes line up.

I'll take a look at it again, but I'm not sure that I can simply 'reverse' the power supply...

So, the air I'm feeling coming out of the bottom of the thermaltake PSU is just turbulence from the fan or something?

 

[John]

Originally posted by: mjrtoo
Nothing seems to line up when trying to mount it that way....The power switch is in the wrong location for the slot and none of the mounting holes line up.

I'll take a look at it again, but I'm not sure that I can simply 'reverse' the power supply...

Please look at the pic PurdueRy posted and reverse the mounting plate.

So, the air I'm feeling coming out of the bottom of the thermaltake PSU is just turbulence from the fan or something?

Hold a Kleenex up to the fan and see which way it moves.

 

[mjrtoo]

Yeah, reversing the mounting plate...that's what I've done. There's a reason that picture is not showing the plate attached...because it won't...

The flame from my lighter gets blown out from under the big fan, and also from the back of the PSU.....

 

[John]

Is the fan in your TP750 mounted the same direction as this pic? If it is then it should be sucking in and exhausting out the back through the honeycomb grill.

 

[GalvanizedYankee]

If the fan were reversed to suck air, none of the caps or coils on the pcb would get much cooling air. The fan needs to be blowing down onto the pcb.
On average a PSU with a 120 fan will offer about 80+cfm@12V, while a PSU with an 80mm fan will only need to drive 55cfm@12V at most.

 

[mjrtoo]

I'm confused, who's right?

To me, it would make more sense to pull air from the case through the PSU evacuating to the exterior...especially in my situation with the PC-A10 case...

I'll check out the fan direction tomorrow.

 

[John]

Originally posted by: mjrtoo
I'm confused, who's right?

To me, it would make more sense to pull air from the case through the PSU evacuating to the exterior...especially in my situation with the PC-A10 case...

I'll check out the fan direction tomorrow.

Essentially that is what all three of us are saying.

 

[mjrtoo]

Perhaps I read Yankee's post incorrectly...but at any rate, looks like it's time for a side panel mod.

 

[Zepper]

Yes, all PC PSUs are designed to pull air from inside the case and blow it out the back (or whatever side the exhoust opening is on these days - not always the back any more esp. when talking Lian Li...) regardless of the arrangement of fans. Lian Lis often have reversible or interchangeable PSU mounting plates. You should have at least an inch of clearance on the fan side of your PSU for it to intake air - the more the merrier. Rotate the PSU or plate or interchange the mounting plates until you do. If you get a second PSU, it should NOT have a side fan like the ToughPower unless you are sure of adequate clearance for intake air - get one with a straight thru air flow like most PC Power & Cooling, Zippy and many Seasonic PSUs.

When buying exotic cases, always examine them carefully before choosing components for them. You may need specific types of mobos, PSUs, HSFs, etc. to match with the peculiarities of the cases - again especially L-Ls. <sigh> . It comes from the case designers not really understanding (or even caring much about - check some recent LL cases for examples) the functional requirements of the major components. L-L seems to do it because they can... <sigh again>

.bh.

 

[mjrtoo]

Yes Zepper, Lian Li does prove to be challenging when trying to make a system work in their cases. But, that's part of the fun of it as well I suppose. But there are some glaring errors of judgement, like the top mounted fan that hangs over the motherboard, I mean come on!!!

Luckily I noticed that before I bought the case and purchased a cooler that would fit on the CPU and the case (although that's another story).

Thanks for the tip(s).

 

[Zepper]

And some cases pretty much require a side-fan PSU. As they put a vent in the case right next to where the side fan should be located. Has the added benefit of isolating the PSU cooling air circuit so the PSU should never get warm and have to ramp its fan up. Good for super low noise rigs.

.bh.