# Manual on Antec 300 says to mount PS inverted if it has a bottom fan?



## lostxpuser (May 7, 2006)

I just got a antec 300 ( http://www.antec.com/pdf/manuals/300_EN manual.pdf ) and a corsair PS from the builder series (Corsair Builder Series Power Supply Units ) 

The manual clearly states that PSUs that have air intakes on the bottom should be mounted inverted on the 300. 



> Note: _Power supplies with fans on the bottom of the power
> supply will need to be mounted so that the fan is facing the top
> of the case._ Three Hundred provides mounting holes for power
> supplies with standard mounting layouts to be installed upside
> up or upside down.



So what is the rationale for this? 

There *IS* an airgap below the PSU slot so its not like the air-intake for the PSU is blocked. I guess it wouldn't make much difference as the air temp won't be drastically different in that area (at least for me).

But its still pretty confusing.

Pretty good pic that gives some idea of the airgap - probably about .25"


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## loda117 (Aug 6, 2010)

Some of the new cases are coming with this 
Mine has the same exact thing 
Purpose of it is so that your power supply is always sucking in cold air from under the case not like it used to be before when they could only get air from inside of the case which is already hot 
The only set back to this is that if you do not have the case sitting on flat surface or the area around the case is dusty it will suck in more dust 
If you are planning on doing it the way it shows it in manual i would suggest buy an outside air filter to be placed where the air gap is to reduce dust intake


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## lostxpuser (May 7, 2006)

Well, there is no air intake on the bottom of the 300, only the outlet on the top. With two 120mm front panel fans (which are filtered) - one of which is directly inline (and not likely to have any obstructions), that would limit the PSU from getting air directly routed to the air gap area, I would think it would be acceptable. Even if there is some reduction in the PSU fan to draw air in, it should be readily supplied to it from the lower fan.

I did put a question in to antec. It will be interesting to know if there was a case redesign and just no change of documentation or what.

Actually, I think mounting it with the fan down will likely get more cold air. It wouldn't be disrupted by any other airflow. I would think the lower fan would direct laminar air along the bottom of the case and would easily be picked up by the PSU intake.


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## Tyree (May 10, 2009)

I've done a bunch of builds with the 300, as well as other bottom mount cases (with and without venting below), and have mounted all of the PSU's with the fan facing up. None have had any issues at all.


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## lostxpuser (May 7, 2006)

So, would you completely recommend AGAINST doing a bottom mounted fan or would it be something you would consider (with the dual fans offered from the 300? )

I would actually prefer it be mounted right side up personally (and I will probably not even run a video card that requires external power - which I know, could make it somewhat of a wash with the inverted PS).


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## Tyree (May 10, 2009)

I would not suggest using the PSU with the fan facing down in any case that does not have venting below the PSU mount. You can't see it once the case side is on.


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## lostxpuser (May 7, 2006)

yeah, thats cool. Its not completely an aesthetics issue, but that was part of it. It seems the cables just laid out a little better that way. But I imagine its pretty moot.

I measured it at lunch, its about .5" of an airgap.

thanks - I will probably go inverted.. but it will be kind of an irritant.


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## Tyree (May 10, 2009)

You could make venting holes in the bottom or cut out a section and use a fan grill guard/filter to cover the hole.


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## lostxpuser (May 7, 2006)

Yeah, I went ahead and installed it inverted. Corsair obviously likes to have a little advertising bc they DID put a label on the otherside of the PS and inverted it relative to the other label. So it still appears as expected. 

Antec DID reply and say the PS could be installed either way. 



> Comment: Hello xyz,
> 
> Either way is fine - Our position is that the air flow would be better on the top.
> Thank you,
> ...


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