I’m also an owner of this chasis. I’ve got mine full to the brim with 15 HDD’s. Recently I was not happy with the temps of my drives, so I switched from the air blowing in from the front (three 120mm fans), through the middle set of fans (3 120mm fans in the middle inside of the chasis), and out through the back (2 80mm fans), to out through the front, so in from the back starting with the 80mm fans, through the 120mm middle fans and out through the front.
Seems my results are better temps, but this seems counter intuitive. Everything I’ve known has always been the opposite.
I’m gonna offer my reasoning for why I tried this, and then why I think it might be providing better results. And my hope is to find an optimal solution as well as to share my results.
So, I decided to make the switch when I kept notice that the front of the chasis was warm. At first my thought was, I have the fans in reverse, so I checked them, and no, they are pulling in from the front and blowing into the case as expected, but I could feel a radiant heat. So I put some paper in front to see if it was sucking in, and it was. It hit me that what I think is happening is that the fan is blowing the air against the 3 filled drive cages and then just finding space out of the sides somehow, and space out of the front. Basically the fans seemed to only be hitting the very front of the drives and not making it through the gaps between the drives and cages and into the case. My guess is also that the middle fans were just pulling in air from other holes in the chasis, so the CPU never seemed to get hot, becasue air was finding a way in, just not over the drives.
That’s when I thought, maybe, if I can get the air to build up a little more speed, it’ll have a better chance of making over and through the gaps in the drives and cages. So, I flipped all the fans starting in the back, and then the middle and then the front. Now the back is pulling air in and shooting it in over the CPU (it’s unraid and the CPU is never a heat problem), and then it’s getting pulled and then pushed by the middle fans over the drives, where they have some suction because of the front.
To be honest… I have no idea what I’m talking about. I’m not case aerodynamics expert by any stretch. This is all just my guess because I was tired of getting the heat warnings from unRAID.
I’m currenlty in the middle of a rebuild of two drives after an erroneous failure because of not enough power, so that’s when I decided to undergo all this. And while rebuilding (which is disk I/O heavy), the drives are cooler than they have ever been before.
With that, I’m done. Here’s hoping this thread isn’t forgotten and someone else has a similar experience they want to share or help me adjust my thoughts because maybe I’m wrong.