Case Airflow Config

[AJ Kenway]

Hi, I have a Cooler Master N200 case and I have 2 Corsair AF120s (one exhaust and one intake) and a SP120 on my rad as an exhaust. I'm planning to buy another AF120 so that I can have 2 intake fans. Which config will yield better intake?

A
Intake: 2 AF120 1100 RPM
Exhaust: 1 AF120 760 RPM, 1 SP120 760-2000 RPM (variable, radiator fan)

B
Intake: 1 AF120 1100 RPM, 1 AF120 1650 RPM
Exhaust: 1 AF120 760 RPM, 1 SP120 760-2000 RPM (variable, radiator fan)

 

[i7Baby]

A - it allows you to run the two fans off one mobo header with a splitter cable.

 

[AJ Kenway]

A - it allows you to run the two fans off one mobo header with a splitter cable.

I'm not planning to run the intakes on the header. My mobo only has 2 of them and they are already occupied by the 2 exhaust fans. I was wondering if running 2 fans side by side at different rpms would be better or not

 

[i7Baby]

Then I'd split the 2 exhausts off one header and the 2 inlets off the other.

I was wondering if running 2 fans side by side at different rpms would be better or not doesn't matter much.

 

[holyprof]

Running 2 fans at different RPM will give you average airflow with higher noise so definitely solution A. It's better to have them both run at the same speed. I totally agree with i7Baby on using 2 splitters but if you don't want to buy or install splitters the only solution would be buying molex-to-3pin connector(s) with series resistor to lower the RPM. Most of them are direct connection adapters that supply full 12V to the fan. Others supply only 5V which will make the fan whisper quiet but with uselessly low airflow. The best ones offer a 7V output which is the best compromise between airflow and noise. Some fans bring the adapters bundled, like this one:
http://www.quietpc.com/afdp-12025b
The fan i linked is expensive but there are others that are almost as good for around half that price.

 

[AJ Kenway]

Running 2 fans at different RPM will give you average airflow with higher noise so definitely solution A. It's better to have them both run at the same speed. I totally agree with i7Baby on using 2 splitters but if you don't want to buy or install splitters the only solution would be buying molex-to-3pin connector(s) with series resistor to lower the RPM. Most of them are direct connection adapters that supply full 12V to the fan. Others supply only 5V which will make the fan whisper quiet but with uselessly low airflow. The best ones offer a 7V output which is the best compromise between airflow and noise. Some fans bring the adapters bundled, like this one:
http://www.quietpc.com/afdp-12025b
The fan i linked is expensive but there are others that are almost as good for around half that price.

What are these "series resistors" you are talking about? What do they look like? Are they the same as low noise adapters?

 

[holyprof]

Yep, should be the same, just be sure the "low noise adapter" isn't a 5V one. In fact, if you're going to connect 2 fans, the best solution is to use an adapter that "makes" 7V out of 12V and 5V.

http://i00.i.aliimg.com/wsphoto/v0/32316058102/6-Inch-Black-Sleeved-PC-Fan-Cable-Distributor-3-Way-font-b-Molex-b-font-to.jpg
https://usb.brando.com/prod_img/zoom/UPCSF024100_01_L.jpg

 

[AJ Kenway]

Yep, should be the same, just be sure the "low noise adapter" isn't a 5V one. In fact, if you're going to connect 2 fans, the best solution is to use an adapter that "makes" 7V out of 12V and 5V.

http://i00.i.aliimg.com/wsphoto/v0/32316058102/6-Inch-Black-Sleeved-PC-Fan-Cable-Distributor-3-Way-font-b-Molex-b-font-to.jpg
https://usb.brando.com/prod_img/zoom/UPCSF024100_01_L.jpg

Many thanks! I'll try to get a hold off one if I can find them. In the meanwhile, I'll try to make do with the low noise adapter

 

[holyprof]

Glad i could help. To avoid those fan connecion problems, i chose a case with integrated fan controller. Keep that in mind for future builds.

 

[AJ Kenway]

Glad i could help. To avoid those fan connecion problems, i chose a case with integrated fan controller. Keep that in mind for future builds.

Will do. Though I might not get a chance to build another one because I'm aspiring to be a seafarer, currently taking Marine Transportation. So yeah that's a problem lol