Fan Direction

racerboy59 · 6 Mar 2009 at 20:23

Does this sound alright, or am I doing something stupidly wrong? I've got an Antec Sonata III case and a 120mm fan attached to the rear of the case by standard. This pulls air out of the case. I also have a Noctua NH-U12P with two fans connected to it. One is pushing air into the heatsink, and on the other side is the other fan pulling air out of the heatsink. Directly in front of this is the Antec case fan, which is about 5 cm apart. I have excellent airflow for the rest of the case by the way, but I just wanted to know if there is a more efficient way to place my fans.

Diggsy · 6 Mar 2009 at 20:43

So long as the airflow is all moving towards the exhaust fan, then it's fine. Although the 2 fans on the NH-U12P is probably a little overkill, but since when did that matter

racerboy59 · 6 Mar 2009 at 23:21

Thank you for your reply Diggsy

All I was worried about was that if two fans are close to each other and both spinning in the same direction, there might be some unneccessary resistance caused. Obviously physics is not my strong point.

cje · 6 Mar 2009 at 23:27

Put your hand alongside then noctua fan and the antec case fan. If you feel air is deflected against your hand, then there might be a little turbulence caused, but I wouldn't bother. I've got 2 Noctua's, and even replaced the case fan in an Antec 1200 with another identical Noctua. It got me 1 degree temp difference.

The benefit of the 3rd Noctua is that its spinning at the same speed, and cfm, therefore blowing out all the air that the cpu heatsink expels. (in theory anyway).

Not worth the effort.

Diggsy · 6 Mar 2009 at 23:34

racerboy59 said:
Thank you for your reply Diggsy

All I was worried about was that if two fans are close to each other and both spinning in the same direction, there might be some unneccessary resistance caused. Obviously physics is not my strong point.

No worries. You would only really encouter resistance if they were very close to each other, or the last fan in the chain was a lot slower spinning than the others.

Adam123 · 6 Mar 2009 at 23:35

front = 2 intake
back = 1 exhaust
side = 1 intake

(all antec 120mm tricools)

top = 200mm exhaust

Are mine, seem ok... Turbulence? its a pc case lol, not a plane? what diff does "turbulence make" ?

cje · 6 Mar 2009 at 23:42

My 2nd Noctua and the Antec case fan were only 2 inches away from each other. The problem I had that the Noctua was running faster than the Antec one, some hot air from the cpu was "bouncing" back into the case. So I increased the speed of the Antec one, but that made more noise, which I wouldn't allow. And they had different cfm at same speeds.

So I just replaced the Antec case fan with a Noctua one. All running same speed created a kind of wind tunnel in effect and the hot air just gets blasted straight out the back. And not some spilling back into the case. (Yes, I get quite bored sometimes.)

chiLLZ · 6 Mar 2009 at 23:43

I mounted my exhaust case fan outside the back of the case to create slightly more gap because it was about four inches from my thermalright 120 push pull setup. I did it because if anything the fans looked ugly so close together.