Optimal Dead-spot Elimination

[BonzaiDuck]

Does anyone have a confident or authoritative idea of the minimal but optimum distance separating a two-inch fan hub and cooler fins? That is, how far to separate the fan from the fins such that the dead-spot is effectively reduced to nothing?

 

[ClockHound]

From my crude experimentation, I've found a 1 inch (25mm) deep shroud is sufficient. Diminishing returns from there. Could also try experimenting with Venturi tube mounting. Here's an automotive fan shroud optimization paper - more diminishing returns of the day. ;-)

 

[BonzaiDuck]

Well, I absorb your experience -- like the Blob ate theater-customers! Like John Carpenter's "The Thing!"

An inch is about 25 mm, or the thickness of a 120mm fan shroud. So we're back to my easiest default design solution. Of course, one can buy a clear plexi shroud for about $9, which is more like 20mm thick.

It DOES make a difference: one of my air-cooled machines has a 120mm fan with a 25mm stand-off (old fan shroud) hanging on the cooler. Another member ducted an H80 AiO front and back with some beefier fans and got some good results on an i7-4790K.

 

[ClockHound]

I keep almost all my intake fans shrouded in secrecy too. Or at least 25mm of discretion.

 

[BonzaiDuck]

I built a Lexan and foamboard motherboard duct for a Stacker 830 fitted with its crossflow fan as exhaust.

The duct fits in the case so perfectly solid and snug that I think I can mount a CPU fan on it with a fan-shroud-duct or the 20mm "clear" unit maybe a millimeter from the cooler. And when I have to remove the duct-plate, I would only have to just . . . . slide it out of the case . . . after unplugging the fan wire, of course . . .

 

[ClockHound]

You've got the wireless fans on your Xmas wishlist, right? ;-)

Sounds like a slick mod - will you be posting some pics of the world's most modded Stacker? (Ok, probably on 20th most...but most shrouded, I'm sure)

 

[BonzaiDuck]

Here are duct parts, including the clear plastic door with 4x 140mm potential. I had to trim off some very thin pieces of plastic to allow a 159mm heatpipe cooler and fan to fit with no interference with the door. Some people chuck the spring-loaded door, boast side-panel modes with 1/4" Plexiglas or Lexan and holes drilled for 2x 120mm fan-mounts. This eliminates the ferrous perf-steel used on this otherwise-aluminum case, adding something to potential EMI or RFI interference -- not my field, but you understand I'm sure.

The stacker gives you two pairs of front USB2 ports, a firewire and a L-R 3.5mm audio pair. But there's no eSATA. So one would buy -- for $7 -- a two-port SATA-to-eSATA converter-plug with two screws, fit it to an old 3.5" floppy-port case-face-plate, and use it to build a nicely-fitting plug that fills the handle recess in the very top of the case. A picture of the amateur approach to wiring two LEDs (power and PCI-E SATA card) to the rear of the plastic recess holding the plug follows afterward:

The eSATA ports are dead-center between the LEDs. The Stacker's top vent is fitted with a Lexan and foam-board cover that blocks the vent.

Here is the rear view of my soldered-extended LED and the rear wiring behind the handle-recess:

The filter made of 3-ply foam-board, and old HAF filters -- to fit two 140mm fans separated by 1/2". I did this so I could use the 140's with the original drive cages. All fans are completely isolated from metal with Spire fan-corners and rubber mounts:

Here is the filter installed on the two Akasa Viper fans. It makes a precise interference fit with the two fans, and it can't come off the fans anyway with the Stacker door closed. They just hang on the fan frames and further contribute acoustically:

The motherboard duct installed. I think I can mate a fan vertically to it right on the edge where the memory ends and the cooler begins. I could do it with shock-absorbed screws, but the duct-plate is already isolated from case metal -- and barely touches the motherboard or pan. Forward between mobo and drive cage, there is a Crossflow barrel fan reversed from design-intention. it draws air from under the mobo-duct and ALSO from under the mobo, exhausting to the right case-panel:

Since the vented mobo pan becomes intake directed toward the barrel fan, it also gets a magnetic filter using same concept as DEMCiFlex [see the 2x140mm filter on the hinged door of the first picture]:

 

[BonzaiDuck]

By the way. No metal has been cut or removed from the stacker, and the hinged plastic door still functions the way it did out of the carton. It lost a few grams of plastic. Hardly noticeable.

 

[ClockHound]

Wow! You could be working as a 1/8 scale HVAC engineer. Oh, wait. You are. ;-)

Is this the rig your 6700k will be going into? If so, and it were me, afraid I would be cutting some metal. Those drive racks in front of the cpu cooler would be the first casualty. ;-)

 

[BonzaiDuck]

I have a logistics and warehousing problem. I only have so much available storage in this house. Things like extra computer cases could become a problem.

But I've committed to sell one of my systems to a friend -- and whenever I choose to cut it loose. He wants the whole enchilada, so subtract one HAF case.

On this project, I'd been looking at the Corsair Vengeance C70 for some time, and ordered it. But while waiting to pull the checkout string on the project, I used the Stacker to build a replacement for my server. And while I was doing that, I started working on these ducting possibilities you'd only bother with for a workstation or gaming system. Most of that work is done, but the duct will need modification for the LGM cooler.

It looks as though the server rebuild will go into the C70 for the time being. Another machine upstairs also could deserve a new case, and all this will shake out in a round-robin process.

I have to think about it. But with the Stacker, 80% of the work has been done to extend temperature improvements to one or two graphics cards. I actually chose "short" cards just so they'd fit with the Crossflow fan in the Stacker box. So the first dGPU that goes in there will be a Gigabyte GTX 1070 "mini"/ITX.

For what objective would you want to cut the drive-rack frame? Basically, that's just two flat pieces of aluminum with screw holes for cages and trays. All the cages and trays are isolated with rubber fittings. If you can fit a 140mm-wide radiator between the two sides, why cut it up?