AIO Push/Pull fan configuration

[Loffel1994]

Dear LTT-Users,
is it advisable to use a pressure-oriented fan as a Pusher for an AIO-radiator and an airflow-oriented fan as a Puller?

In my case (pun intended) I'm planning to upgrade my fans, since I'm dissatisfied with their noise emission. I'm currently using a be quiet! Silent Loop 2 120mm in a push/pull configuration and two additional case fans (all of them being 120mm pwm). I intent to repalce my AIO-fans with a Noctua NF-F12 (93,4 m³/h; 2,61 mmH2O) as a Pusher and a NF-S12A (107,5 m³/h; 1,19 mmH2O) as a Puller. My reasoning behind of this is, that the Puller doesn't need a high static pressure since the Pusher is already taking over this task, but should rather focus on dispensing the hot air being pushed through the radiator. Also, being the actual exhaust of my case and thus the most noticeable fan due to its placement, I would benefit from the Pullers low noise emission of 17,8 dB at 1200 rpm. But this is just the reasoning in my head.

Am I possibly bottlenecking my airflow with this and/or even generating oscillations with those differently layed out fan blades? Is it better to use an NF-A12x25 (102,1 m³/h; 2,34 mmH2O) or the same NF-F12 as a Puller as well?
My goal is to get the best Cooling/Noise-Efficiency out of my system.

Thanks in advance!

[Tegneren]

The airflow fans are made for not having (much) resistance on either side of it. It cant move air that's not there, so it will mostly just move the air that the pusher provides on its own. Moving the air through the radiator at higher rate are the main objective with a push pull config, so if only one of them are moving the air through it, the gain from the other fan are minor. With two static pressure fans they will help each other.

 

But what I think will be more beneficial is getting a bilgger AIO, a bigger radiator area means more effective cooling at slower fan speeds, and therefor lower noise.

The 120mm AIOs are basically worthless. A much cheaper air cooler will do the same job, or even better, at lower cost and complexity.

 

[WoodenMarker]

NF-F12 push and NF-S12A pull works but I'm not sure if it would be as good as NF-A12X25's.

NF-F12 is designed for push and pull isn't advised without a spacer / grommet since the acoustics are worse.

[thrasher_565]

the cost of 2 fans is not worth the 1c drop unless moeny is not the problems or want it for looks i guess. thicker rads might need push and pull and might get a bit better then 1c drop but unless your maxed out of rad space it cheaper and better proformace to just add another rad. even if its a skiiny one.

[freeagent]

With my H100 running P/P it was 3-5c difference, but I was using thicc fans.

[Loffel1994]

First of all, thank you for your replies! Your feedback has definitely influenced my decision process.
I've been overthinking my plans and do agree that the NF-A12x25 are the best fans for both airflow and static pressure. Given Noctua's own flow/pressure-chart, which you see down below, they deliver the benefits of both the F12 and the S12A fans. So I bought 2x NF-A12x25 as Push/Pull for my 120mm radiator and additional 2x NF-A12x25 as case fans, since they're facing dust excluders and therefore require a bit of static pressure. I will also move the radiator from the exhaust to the intake of the case, running my CPU-temps even lower. Unfortunately my case together with my drives do not allow for a bigger radiator. This is something I may consider upgrading in the furutre. Currently I'm reaching 60°C during gaming while hitting 65°C as peaks (it's a R7 5800X btw). With Noctua fans and the new position, I'm sure they will bring an improvement. And since the exhaust fan now doesn't have a radiator mounted right to its front, I'm considering in buying a single NF-S12A to spill out the hot air around my motherboard. Still not sure though, if an NF-A12x25 is still better for this task 

[narrdarr]

Airflow optimized fan are pretty worthless in pcs. They don't handle resistance and there's always resistance somewhere. Second, push pull on 99% of aio's is also worthless. The fin density isnt high enough nor are they thick enough for there to be an advantage to using push/pull. Third, why spend more on the fans than the aio?