Airflow management and AIO installation dilemma

[Alex Wong]

Hi Guys. I am a newbie to build a PC. I try to explain my situation about my AIO cooler and the airflow management of my PC. Hope you could understand.

Here is the link to see the first build of my PC:
https://drive.google.com/file/d/1NU5-fTbIQe0xlN4kBf5D1Ds0fA9uGePv/view?usp=sharing

To begin with, I mounted the AIO radiator which is NZXT Kraken X63 RGB with two 140mm fans on the top while there are three stock fans of my PC case that are preinstalled at the front to suck the fresh air. My PC case is Corsair ICUE 4000X RGB.

With reference to the AIO cooler and my PC case specification, the airflow to pull the air out from AIO fans are 30.39-91.19CFM but the maximum airflow of the three Corsair stock fans, which is Corsair SP120 RGB, has a maximum capacity of 52CFM.

Problem 1
By calculation, the maximum airflow of intake is 52x3= 156CFM, and the maximum airflow of the exhaust is 91.19x2= 182.38CFM. I am unhappy with the negative air pressure because I am afraid of dust accumulated at any holes of the sides and the back, and even the port of the back I/O and the HDMI ports of my display card. More importantly, I have not installed the exhaust fan at the back. The problem gets worse if I add it.

Problem 2
I placed the AIO pump at 3 o'clock orientation. The radiator is mounted at the top and the tubes are down. I will show you the video about my AIO operation.
Here it is https://youtu.be/9t6eytEBWa8
You can hear from the video. It seems there is noise from my PC but it's not severe. I am not sure it came from air bubbles inside the tube. Can I confirm? If my AIO pump is placed wrongly, Can I would re-install it at 6 o'clock orientation?

I have two solutions in my mind.

The first is to replace three stock fans with 2400RPM fans but I will be unhappy with no RGB effects. Also, positive air pressure can not be guaranteed once I install the exhaust fan at the back.

The second, which is my preferred choice, is to change to mount the AIO radiator at the front with tubes down. Three stock fans will be removed at the front and I mount two of them at the top and one of them at the back. That should be positive air pressure now. However, the temperature of the graphics card may be increased due to fresh air being sucked into my PC is warm as a result of the heat release from the CPU. If so, should I get an extra fan for my graphics card?

Please let me know your advice and thanks in advance.

 

[Grimley]

Hello
This video may give you an insight into AIO's.

My suggestion is to replace the fans on your AIO with Corsair ones. Like these:

My basket at Overclockers UK:

• 1 x Corsair LL140 RGB, 140mm Dual Light Loop RGB LED PWM Fan, 2 Fan Pack with Lighting Node PRO= £69.95

Total: £78.65 (includes shipping: £8.70)
​

Now I read the specs on the NZXT fans & I for the life of me can't find a power lead to spin the Fans, only the RGB controller.

Corsair = plug the fans RGB lead into the lighting node for the RGB. Fan power leads into the PWM fan headers on the board. Slow down the fan speed using the fan control in the Bios (if your board has this.)

 

[Tanin'iver]

I couldn't hear the noise in that video, but if you suspect air trapped, tilt the case, shake it around, turn it on it's side, whatever until it's sorted.

RE: The airflow figures, there is an error in your calculations - those numbers assume the fan is running at 100% speed, I guess you won't be doing that unless you love fan noise.

More importantly though, the figures they quote will be based upon an assumption of unobstructed airflow, since they are marketing information and bigger number wins. They won't advertise the figure taking into account the resistance of the radiator they are pushing the air against - and that will be significant.

Unfortunately I can't tell you exactly how much difference it will make. It would be almost impossible to simply calculate it, and pretty tricky even to measure it - you'd need to adapt the "black bin bag taped to the fan, measure the time to fill it" test and try both with and without the radiator in the way.