Rackmount noiseless NAS + rig

[alryaz]

Hello, folks! I'm looking for a silent, perhaps almost noiseless cooling solution for a rackmount chassis.

I've been heavy into rack mount stuff recently, transitioning from having several full-blown tower cases (mostly AeroCool ones from 2013) to 4U rack mount systems. Didn't do much planning beforehand, but ended up with 2x 4U cases with misaligned server rails (mid-hole alignment, 3U rails for a 4U due to easy availability) and one 3U case which I'm most likely bound to throw away in the gutter (or sell on eBay).

All that is installed in a 12U cabinet designed for (here comes the first constraint) being wall-mounted. Tempered glass front, 2mm metal back side wall. Here are the specs (rigs go from top to bottom):

 

#1: Cabinet

• Manufacturer: Hyperline
• Model: TWB-1266-GP-RAL9004
• Cooling:
• 2 * 200mm intake AeroCool Silent Master (running at 12v) (modded into side panels using a dremel)
• Clearance (from adjacent wall-like objects):
• Top: 2cm
• Left: 20cm
• Right: 110cm
• Bottom: 3cm
• Back: 10cm

#2: Main rig (8 hours/day operation)

• Case: Procase B440-B-0
• Cooling:
• 1 * 120mm intake
• 1 * 80mm outtake fan
• Cooler Master Hyper 612 v.2
• Arctic MX4 Thermal Grease
• CPU: Intel i5-7600K
• GPU: NVIDIA GTX 780Ti
• Storage:
• Samsung NVMe 512GB PM981 SSD
• Crucial SATA 480GB M400 SSD
• Seagate 1TB SSHD
• Motherboard: ASUS Z270-P PRIME
• PSU: Corsair CX750M

#3: NAS

• Case: Procase EB400L
• Cooling:
• 2 * 80mm intake fans (from SATA backplanes)
• 2 * 80mm outtake fans
• Intel Stock Cooler
• Arctic MX4 Thermal Grease
• CPU: Intel G3900
• Motherboard: MSI H270-A PRO
• PSU: FSP Generic 450W PSU
• Storage:
• 6 * 3TB Seagate mixed Surveillance & NAS drives
• 2 * Chieftec 2131SAS backplanes
• 1 * NVMe M.2 drive (coming soon, 6x SATA didn't allow for a SATA M.2 installation, correct me if I'm wrong)

#4: UPS (3U probably, still coming)

 

Now, I think I would be much better off with something gigantic like a W200 tower case, which I would be much happy to get, except that it takes at least a $800 premium, and all the cases and fans I got for less than $200 (including SATA bays, rails, cabinet itself), so that leaves me with additional $600 of difference + $400 for DIY/AIO cooling solutions.

So far, my 200mm fans case made a noticable 6°C difference in overall temperature, however my CPU idles at 50° (without overclocking) and is able to turbo without thermal throttling for around 3 to 4 minutes; and then it throttles hard, dropping down almost to 2.8GHz.

 

I'm considering the following options so far:

• Water-cooling radiator for 1U with QD3 and a custom loop for both rigs (separate pumps probably)
• Replacing CPU cooler (612 didn't fit into my 4U case, so I had to cut off four topmost blades as well as trim down copper tubing; maybe it's useless now)
• Delidding CPU, replacing TIM with liquid metal, as well as putting a copper IHS afterwards
• Drilling backside holes for 4*200mm outtake fans
• Replacing tempered glass with acrylic and putting intake fans on the front of the cabinet
• Adding a 120mm AIO for the CPU in my main rig
• Soundproof foam all over the cabinet as well as cases
• Changing PSUs to low-noise ones (like FSP Hydro G series)

Does anybody have ideas regarding available options?

 

Pics of the setup provided. Cable management is a mess right now, but the setup is still in progress.