PSU Orientation on Bottom of Case

[pafnooty]

I've built a few PCs in the past, but nothing for a few years. Now I am starting a build in a Corsair 650D case with the PSU on the bottom, which is new for me.

Some 650D reviews mention that you have a choice for orientation of the PSU at the bottom--fan on the bottom (to the outside) or on the top--but none I've read says any more about it. My quick analysis says that if the fan is at the bottom it will cool the PSU better because it's drawing in outside air, but the heat from the PSU will rise and warm up the rest of the components. But if the fan is on the top, it will be drawing warmer air into the PSU but helping with airflow of the case as a whole.

My guess is that the first scenario with the fan on the outside is probably better, in part because there are plenty of fans in the case, but I would really like to hear some expert opinions on this.

Thanks!

 

[scout_03]

i use a bottom psu and it pull air from below and send out back with fan did not have and issue with temp this way.

 

[pafnooty]

Thanks! I appreciate the information. I think I'll go ahead and install it that way.

Cheers!

 

[apache_lives]

NOOB

face it up so it pulls air out of the case (no heating problems either whatever your talking about)

otherwise you end up sucking all the dust from under the psu/case and blocking the filters they always put there and you can never see the problem till you kill the PSU, also limiting airflow to the psu (all of this is a fire hazard)

dont listen to scout_03

 

[Apropo]

I've built a few PCs in the past, but nothing for a few years. Now I am starting a build in a Corsair 650D case with the PSU on the bottom, which is new for me.

Some 650D reviews mention that you have a choice for orientation of the PSU at the bottom--fan on the bottom (to the outside) or on the top--but none I've read says any more about it. My quick analysis says that if the fan is at the bottom it will cool the PSU better because it's drawing in outside air, but the heat from the PSU will rise and warm up the rest of the components. But if the fan is on the top, it will be drawing warmer air into the PSU but helping with airflow of the case as a whole.

My guess is that the first scenario with the fan on the outside is probably better, in part because there are plenty of fans in the case, but I would really like to hear some expert opinions on this.

Thanks!

If you weren't supposed to mount the PSU with the fan facing down the case manufacturer would have never put a dust filter on the bottom. There is a filter under where the PSU sits: http://youtu.be/ETQ2KgqcfWY?t=4m28s

Unless you have really long shag carpet there is no good reason to mount the PSU with the fan sucking hot air from within the case. Though its not necesarily a problem to mount the PSU to suck the hot air out of the case, keeping in mind heat kills electronics so it doesn't make sense to add more heat to a component than needed.

 

[jemm]

^ bump +1

 

[pafnooty]

Thanks to all for advice. I went with the orientation the case is designed for (fan on bottom) and it works beautifully. I appreciate the warnings about dust and shag carpets!

Cheers!

 

[jonjonjon]

NOOB

face it up so it pulls air out of the case (no heating problems either whatever your talking about)

otherwise you end up sucking all the dust from under the psu/case and blocking the filters they always put there and you can never see the problem till you kill the PSU, also limiting airflow to the psu (all of this is a fire hazard)

dont listen to scout_03

before you call someone a noob you should probably have a clue what you are talking about.
http://www.tomshardware.com/reviews/cooling-airflow-heatsink,3053-4.html

 

[pafnooty]

Best answer selected by pafnooty.