Looking for advice on fan placement

[kskerns]

Good afternoon, folks! Quick question today.

I am building a new rig in a Rosewill R5 case.

I will have a single graphics card and a cooler master evo HSF in there, hoping for a very mild overclock on an i5-3570k.

What I'm looking for is some advice on placement of my last fan(s). The case comes stock with two intake fans in the front bottom by the drive bays, I have left those there. I have replaced the top-rear exhaust fan with an aftermarket. That leaves me with one stock fan (if I choose to use it) and one 140mm Corsair that I'd like to use.

My original plan was to mount the 140mm in the top as a second exhaust fan, but now I'm having second thoughts. I can mount it right or left of the HSF, but it seems like that would interrupt the airflow of the heatsink fan pushing air across the fins and then out the back exhaust. I know an inexperienced user can do as much harm as good by messing up their airflow so I thought I'd pitch it here first.

Thoughts? Thanks!
kskerns

 

[ksham]

The EVO comes with one PWM fan and that is good enough, especially since you have an exhaust fan to the left of it. As for the other fans, I'd just leave them out, unless there are more intake options. You can mount it on top as intake, but it not a big deal. It'll probably just pull in more dust and hot air naturally rises, so more air pushing it down is not optimal. No need to fight mother nature.

 

[kskerns]

The EVO comes with one PWM fan and that is good enough, especially since you have an exhaust fan to the left of it. As for the other fans, I'd just leave them out, unless there are more intake options. You can mount it on top as intake, but it not a big deal. It'll probably just pull in more dust and hot air naturally rises, so more air pushing it down is not optimal. No need to fight mother nature.

Thanks for the quick response! I wonder about myself. I could probably mount the 140mm to the side panel as it is perforated, assuming that fits with the tall HSF and graphics. But in that location I would expect it to be a third intake for cool air to the GPU. 3 in, 1 out seems like bad balance.

I wonder why they designed the case with enough room to mount two upper fans if it is superfluous to use them?

 

[ksham]

It's not. You can speed up the cooling by mounting 2 exhaust. Of course, that creates negative internal air pressure. Some people prefer that. I prefer the opposite side -- positive internal air pressure.