Power supply fan, which direction should it face, up or down?

[garyhope]

I've done a new build with a Cooler Master HAF 912 case and an Antec BP 550 Power supply. The PS mounts on the bottom of the case and has a screened vent or air intake on the bottom of the case.

My question is should the Antec BP 550 be mounted with the PS fan facing downward over the case floor screened intake or should the PS fan be facing upwards into the case? It looks like the screw holes on the PS line up with the screw holes on the case with the fan facing upwards.

Does this really matter?

Thanks all.

 

[rolli59]

Fan down for better cooling of the PSU, that is the reason for the vent there!

 

[ko888]

The screw holes allow you to mount the PSU either way.

Fan facing down is my recommendation.

It's better to have the PSU's intake fan pull in cooler outside air than to pull in the pre-warmed case air. PSU's operate more efficiently with cooler air. Also the case's internal air flow doesn't get disrupted.

 

[fb39ca4]

^that, and otherwise the PSU fan and the GPU fan are competing for air.

 

[garyhope]

Thanks guys, I'm going to try it fan side down. I emailed the Antec site and they also suggested that the fan side be down next to the screened air intake on the bottom of the case. Makes sense. Thanks again everyone. It's always good to ask the advice and wisdom of the Tom's Hardware crew and experts.

 

[garyhope]

Well guys, I did it. I switched the PS so that the fan is facing down and right above the screened air vent opening on the bottom of the case. No problem with the screw holes. The PS is secure in the case and one other advantage is that the label and info panel on the PS is now facing outward so you can see it and all the info is right there.

So thanks again guys for all you help and expertise.

 

[garyhope]

Can there be such a thing as too much airflow in a case? Can there be conflicting airflow that might actually be counter productive or not cool enough?

Is it a bad idea to leave one side of the case off with the components exposed to the open air?

Can you get better airflow with the case closed properly so the airflow is more directed for a kind of venturi effect?

 

[rolli59]

Open case can disrupt an airflow path created by fans and leave dead pockets of air around components.

 

[ko888]

Leaving the side off prevents airflow containment (i.e. proper airflow is lost).

 

[garyhope]

Wow, thanks very much rolli59 and ko888. That's good to know. I thought something like that might happen. Thanks again.

 

[garyhope]

Best answer selected by garyhope.