Prototype Updraft - 16.8L vertical chimney for large air coolers

dieaready

Cable Smoosher
Original poster
Jan 29, 2021
10
10
I'm relatively new to the SFF world and I've not been able to find a case to my preference so I decided to design my own. I prefer air coolers and am fairly obsessed with efficiency, so my focus is on a case that would fit the biggest air coolers with no thermal recirculation, especially between the CPU and GPU. I built a quick prototype from AL brackets and plates, which proved my concept (equivalent or better cooling compared to an open bench), and worked with a friend to put it in CAD for refinement.



Updraft MK1

Size: 275 (L) x 180 (W) x 340 (H)
Footprint: 49500 mm^2
Volume: 16.8L
Motherboard: M-ITX
CPU cooler clearance: 165mm
GPU clearance: 325mm long, 68mm thick
PSU: SFX, might fit SFX-L
Material: Steel frame, Aluminum panels, Tempered glass window
Fan mounting points:
  • Intake: one 120mm fan, two 40mm fans (or one 60mm fan if not using NH-D15)
  • Exhaust: two 80mm fans (main chamber), two 60mm fans (GPU top exhaust, if GPU is under 280mm)

Features:
  • Two orientations, vertical for normal desk mount, horizontal (GPU facing up, IO facing in) for enclosed shelf mount (hot air blows out)
  • Huge air cooling potential, open bench or better performance from the central updraft wind tunnel
    • Potential for low power fanless mode in vertical orientation
  • Separate sealed GPU chamber with no cross thermal flow (seals not pictured)
    • GPU front intake is sealed off from the rest of the chamber, allowing air to only flow through the intake and out through the top and side vents
    • Vented GPU chamber directs hot air up and to the back
    • Adjustable GPU mount allows GPU to be shifted around to seal to the grill at the front
  • Clean thermal flow - no dead zones or thermal recirculation for both CPU and GPU
  • Tempered glass window for main chamber
    • TG or solid panels are required to form the wind tunnel, mesh would reduce the effect
    • Possible mesh option for a 240mm AIO
  • Internal deflector to redirect CPU cooler exhaust away from PSU air intake
  • Cable duct: motherboard IO and power cable are located in optimal position for a cable duct/snake to keep things neat

Potential features under consideration:
  • Two 3.5" bays (facing out besides the TG panel) for more IO options or SSD/M2 mounts
    • Alternatively up to two 3.5" HDD or three 2.5" SSD internal mounts
  • 240mm AIO/radiator mount with mesh side panel
  • Extra buttons in different locations (alternative location for power button, restart, reset CMOS, etc)
  • Mechanical vents for GPU compartment
    • Potential for temperature controlled automatic venting, only opening under heavy loads
  • Filter slots for air intake points
  • Leg extensions to increase GPU clearance to 350mm
  • Thermal pads to sink heat from motherboard VRM/rear NVME to the exterior panel
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GPU vents on the right direct air up and to the back. Circle is cut out for a power button and 2 USB ports are available below it. Convenient position for peripherals to connect, and no headphones jack due to proximity to motherboard IO.


Note the deflector above the NH-D15 that deflects hot air from the PSU intake. PSU drops in from the top and can be mounted horizontally in various orientations. SFX-L PSU technically can fit, but would be extremely tight for the cables. 120mm slim fan fits when using the NH-D15, considering a drop down bracket to allow a 25mm thick fan to fit. Two 40mm fans, or a 60mm fan feeds fresh air to the PSU intake, while two 80mm airflow fans provide exhaust for the chamber. The empty space in front of the PCIE slot allows space for 3.5" bays, or HDD/SSD mounts.


Bottom panel design is still not yet finalized, will have space for IO shield, and mesh/grill will cover the fans. New panel will allow for a 60mm fan to replace the two 40mm fans. Above the fans is a slot for a PSU passthrough bracket with switch.


Slots for riser and power cables will be covered by rubber/silicone grommets to prevent hot air from entering the main chamber. The slot at the bottom for the HDMI/DP cables will also be similarly sealed off. The entire front of the GPU (intake) would be sealed off from the sides/back (exhaust) so no hot air can be recirculated, forcing all the air out through the vents at the side or through the top mesh. The GPU can be adjusted forwards/backwards and up/down from the mounting points in order to assist in sealing it off. The thickness of the GPU chamber allows for two slim 120mm or 140mm fans to be mounted onto the mesh if a 2 slot GPU is used. The vents along the sides are indented inwards, forming air scoops that works well with conventional axial fan GPUs which blows hot air out sideways.


Solid back panel, the large vents at the bottom 'skids' also doubles up as carrying handles for transportation. The angled rear provides a stable platform when you rock it backwards to access the bottom IO. Still not sure if I should keep it or revert to a standard base instead.


Interestingly, two 80mm fans provides roughly the same amount of airflow as a single 120mm. Airflow focused 80mms are recommended, as pressure wouldn't be a concern for the exhaust. The relatively high velocity from the mostly unobstructed exhaust fans coupled with the lack of side intakes should result in the hot air being jetted away from the case (forming very large vortexes) so there should be almost no hot air being recirculated externally into the case (even when in the horizontal orientation).

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There is still a lot more tweaking and fine detail work left to do, and I'm still undecided about a fair number of features so I'd appreciate any advice/thoughts/comments on this. In theory, it should be able to run both a 5950X and a 3090 at max load without throttling. If I can get enough interest, I will be working to bring this to market (< $200 hopefully).
 
Last edited:

dieaready

Cable Smoosher
Original poster
Jan 29, 2021
10
10
Update 1


Second iteration of my first quick prototype, only missing the front and top mesh and a few other things. Built from AL brackets and 2mm AL plate using a dremel. Dimensions after construction are 271x182x342, which imo is quite impressive since I was measuring mostly by eye and tape measure. Next prototype will be done professionally as this is just a proof of concept for the thermal flow, to prove that it can perform as well as an open bench at the very least.

Specs
CPU: Ryzen 3600
MB: Gigabyte A520I AC
Ram: Crucial Ballistix 3200Mhz 2x8GB
GPU: Gigabyte Gaming 3060ti
PSU: Silverstone SX600-G
CPU Cooler: Noctua NH-D15 (LTT edition)
Riser: EZDIY-FAB 20cm gen 3 riser
Case Fans: 2 Arctic F8s

Max Temps under ~31C ambient, CPU running Prime95 Small FFT and GPU running Port Royale stress test together, all stock settings
CPU: 76.3C (88W)
GPU: 66C (239W)
Testing both outside and inside the chassis gave similar results (+-1C).




Everything fits into place just nicely. Roomy interior becomes tight with the NH-D15 taking up almost half the volume of the CPU chamber. Side vents for the GPU are just wide open for now, and the bottom intake fans are not ready yet (missing mount for the 120mm and still have to order the 40mms). Still very good thermal performance, giving similar results as an open bench when in testing due to how air can only flow through the case in one direction. Note the space above the power button, this was reserved for future additions for SSD mounts or 3.5" bays (for SSDs or IO). Side panels are just cut plastic sheet that serves to block airflow to create the wind tunnel. Just started to contact fabricators this week for cost estimates for the next prototype.
 

dieaready

Cable Smoosher
Original poster
Jan 29, 2021
10
10
This ideas is perfect. But one question, why only SFX PSUs?
Technically it could fit an SFX-L if the PSU is rotated 90 deg, but the clearance for the cables would be even less depending on the orientation so I've not tried it yet (also I don't have a SFX-L PSU). I probably could fit a normal sized PSU but I'd have to increase the dimensions slightly and the case is already larger than I originally intended it to be as I was originally designing for the fuma 2 instead of the NH-D15. Original specs would have kept it at 12.75L but with only a 280mm GPU and 155mm CPU cooler, which I felt wasn't suitable for most of the new GPUs that came out. I had half a mind to increase dimensions further, which would allow for a full 360mm 4 slot GPU but then it would be much closer to the 20L NR200 just to only accommodate 3 more cards (Suprim, HoF and Aorus Master). If this takes off I might eventually make Updraft in 3 sizes: S-13L, M-17L, L-20L
 

robojim

Cable-Tie Ninja
Jun 18, 2020
179
182
I would find a way to include exhaust fans for the GPU chamber. Hot air rises yes but it's not a very high velocity.
 

dieaready

Cable Smoosher
Original poster
Jan 29, 2021
10
10
I would find a way to include exhaust fans for the GPU chamber. Hot air rises yes but it's not a very high velocity.
You can fit two 60mm fans at the top for exhaust, but that reduces the max length for the GPU (perfect for an ASUS Dual 3070, or say a TUF 3080 with two 40x10mm fans). The whole front facing design will have silicone seals that will isolate the front of the GPU from the sides, which causes the fans to build up positive pressure after the GPU heatsink which then forces air out of the side vents and top, and the whole point of the design is as long as the hot air is not recirculating back into the GPU, you should get almost the same temps as an open bench. I'm still experimenting with the side vent dimensions to ensure that they allow for sufficient exhaust so the pressure would not build up too much in the GPU chamber and hinder the intake fans, but that will take quite a while more.
 
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robojim

Cable-Tie Ninja
Jun 18, 2020
179
182
Depending on GPU design, heat is exhausted from a combination of out through the IO shield like on the older FE designs or in the newer ones as well as out the sides of the card as in the case on a vast majority of AIB cards as well as the new AMD reference designs. Finally you have flow through designs that also throw heat behind/above the card. I think space for exhaust fans would overall encourage evacuation of this hot air from the latter 2 directions
 

dieaready

Cable Smoosher
Original poster
Jan 29, 2021
10
10
Yup, I had the FE models in mind, which was why I made the GPU chamber extra thick to allow for more airflow behind the card from the blowers, and the slots at the bottom and on the wall in between the chambers will also be sealed off as much as possible to prevent bleed through of hot air into the CPU chamber. The goal is to allow the GPU chamber to vent well enough from the sides and top for open bench performance, and also allow for fans for those who want to aim for better than open bench performance. Almost all 3070 cards and below should be perfectly fine, while most 3080 and 3090 cards would be fine (except for the absolute biggest sizes).