Optimal fan orientation

Damo667 · 23 Apr 2014 at 02:16

Hi guys, I've just finished my fractal design arc midi r2 build and I need a bit of advice on fans. I currently have a 240 rad in the front with 2x120mm sp120 performance ed in taking mounted between the case and the rad, same setup in the roof, a 140mm silent fractal fan in the front of the roof above the optical bay also an intake and a sp120 quiet edition exhausting at the rear. My psu is upside down so also removing hot air.

My question is as my temps are high for my liking could that be because there's not enough fans removing hot air from the case? And would the best setup be as follows: leave the psu, have the rear and 3 roof fans as intakes and the 2 front fans as exhaust? I know heat rises and all but with fan speeds inside the case convection doesn't get a chance to take effect does it? What would be your optimal intake/exhaust choice with the fans I have installed?

I should also add that I have a 6ch fan controller on order with the ability to turn them down to 0rpm so each fan speed is fully adjustable (the sp120 perf ed are like jet engines at take off kinda loud).

Many thanks in advance, Damien.

Rroff · 23 Apr 2014 at 03:11

I've usually gone with slight negative pressure without any bad results cooling wise and helps to keep dust down a bit inside the case.

Top fans/rads should always be exhausts IMO - pretty much all mine have had 2x140mm intake fans on the front w/ dust filter, 1x 140mm exhuast at the read + 2x top exhaust and PSU exhausting.

Damo667 · 23 Apr 2014 at 03:29

Thats interesting as everywhere ive read have said positive case pressure to keep dust out. My other option is to make it more conventional and flip the psu the right way, leave the front fans as intakes and switch everything else to exhaust. ive also got the foam filters everywhere apart from the rear. in a week i can see dust collecting in the roof filter already!

Rroff · 23 Apr 2014 at 03:40

Depends whether you've got lots of other unfiltered vents/gaps, etc. or not in the case.

Damo667 · 23 Apr 2014 at 04:05

The fractal seems to generally be well built with the seams looking pretty tight. I have both optical drive bays occupied so no gaps there. The only unfiltered part is the rear fan. There's a foam filter tray on the bottom of the case like the others.

So in my case setup you'd go for the fronts as intake and the rear and 3 in the roof as exhaust? That's what I think I'm leaning towards.