Questions about placing fans in an *air cooled* Corsair 300R case

[CRABBY GUY]

I have seen many pages of advice on placing fans in Corsair 300R cases with water cooling. However, I am seeking assistance on an air-cooled configuration. I would like a slightly positive air pressure and I will place dust screens wherever possible.

1. My case's main heat sources are:
- An overclocked i7-9700K (cooled by a Noctua NH-D15 with its two stock fans)
- 2X16GB 3333 MHz DDR4 sticks
- An EVGA 1060 (This build is for running Lightroom, not for gaming, and this GPU is reported to be sufficient for that purpose. It may still need additional cooling, IMO.)
- 3 SSDs and 2 HDD
- A Gigabyte Z390 Aorus Ultimate motherboard
- A Corsair RM750X PSU

2. The arrangement of the key components are (must be) as follows:
- Mobo edge (next to RAM) will be about 2" down from the inside top of case. It is also close to the inside of the case rear
- 150mm exhaust fan of Noctua air cooler goes right over the top of at least some RAM (with my mobo choice, there should be 5mm of clearance with low-profile memory, say the wizards in Austria) and ends roughly 4" down from the inside top of case
- CPU is, of course, about centered on NH-D15
- PSU is in its usual place, at bottom of case

3. 300R case's factory-provided fan holes are:
- Two side-by-side in the top, one nearly right above the exhaust fan of NH-15
- One fan hole in the back of case, a little down from case top
- Two fan holes in the front of case, toward its bottom

4. Additional venting includes:
- Vent holes, possibly for fans, in the case side cover. (These can be covered with dust filters or small fans. They can be elegantly eliminated with a solid case cover. What is best for my cooling?)
- Small side vents in the case front and rear.
- Ventilation for PSU.
- Misc.

I have initial plans to use exhaust fans blowing out on one of the top holes (a few inches from my Noctua NH-D15's output) and on the top-rear hole. At least one of the fan holes in the front of the case should likely blow in air. Other than that, I am not sure where to start in fan sizing and placement.

 

[Gam3r01]

The "best" config for that case would be 2x140mm intake fans in the front, a 140mm exhaust fan in the rear top, and a 120mm exhaust in the rear.

 

[CRABBY GUY]

-Should the exhaust fan in the rear top speed up (or partially speed up) with the air cooler? (The NH-D15 blows quite a bit of air.)
-Should all other openings in the case be left open including both in the case cover?
-Any method to set case fan speeds?

Thanks!

 

[Gam3r01]

I personally would run all the 140mm fans at full speed, given their size they should be quiet enough under load to do this.
The 120mm I would have the system control with processor/gpu temps.
More open vents the better, heat from the motherboard, etc, should naturally convect out the top of the case. (I personally wish the side panel was solid though)
You motherboard should have plenty of headers that allow for fan control in the BIOS, so you can experiment with what works best.

Essentially, getting as much air into the case is important, but so is getting the hot air out as fast as possible to avoid heating up the GPU.