Fan orientation for optimal cooling

[v0lt_440]

Hi everyone,

I am building an EPYC Gen 2 based system on a Phanteks Enthoo 719 case.

I would like to get your opinion on the best layout and direction of fans to achieve the best possible cooling outcome.

I have 8 X Noctua 140mm fans, 3 at front, 3 at top, 1 at bottom and 1 at the back.

I have a be quite dark rock pro tr4 which can have fan orientation of top intake or bottom intake(not front to back).

Concerns:

- I will populate the shown HDD sleds and am worried I will be blowing too much hot air to the motherboard/CPU and components.

- I am worried the air might just 'swirl around' if I am not careful with the orientation of fans

- Will one fan be enough for exhaust? Maybe there is a better option.

How would you do it if you had my hardware?
[My case and fans](https://i.imgur.com/Hch9btO.jpg)

I have 1 X 120mm fan position available at the bottom, currently unpopulated.

My CPU TDP is 240W. The HDDs are mix of 14/18TB, they seem to run quite warm ~ 45-50C/113-122F.

On this case, I had a Noctua cooler which is front/back and made things simpler.
[Noctua](https://i.imgur.com/qFZ6iB0.jpg)

This bequiet! cooler is up/down and not front/back unfortunately.
With this in mind, if I want 'freh air' to the CPU cooler, logical thing for me is to get if from 'outside', and not the air that has already passed through warm HDDs at front.
So the option either seems from top, or from bottom.
[Be quiet cooler](https://i.imgur.com/yb81BIC.jpg)

Not sure if I am overthinking too much. How would you do it?

 

[alex_stief]

How would you do it if you had my hardware?
[My case and fans]

http://imgur.com/Hch9btO

Almost. You just need to change fans at the top to exhaust, and you are golden. Orientation of the CPU fan is also bottom-to-top.

- I am worried the air might just 'swirl around' if I am not careful with the orientation of fans

That's what we are preventing here by switching to top exhaust.

With this in mind, if I want 'freh air' to the CPU cooler, logical thing for me is to get if from 'outside', and not the air that has already passed through warm HDDs at front.

Common misconception: Just because components are hot, doesn't mean the air passing over them is heated to the same average temperature.
It would take very slow moving air and/or a very high surface area (i.e. proper heatsinks) to come close to that. Conditions that are not met by fans blowing over a few hard drives. The "warm" air might be heated up by 5°C at worst.

So yeah, turn the fans at the top around, and don't overthink it. There is more than enough airflow for the given hardware.

 

[v0lt_440]

Sweet, made the top 3 as exhaust.
Added extra 1 X 120mm at bottom to pull air.
Changed CPU cooler from down to up direction.
Thank you for the suggestions.

Will report back with thermals once everything is up and running.