Dual 140 mm Fan to 200 mm Metric Duct Shroud

Description

Dual 140 mm fan to 200 mm metric duct shroud

This is the largest metric collar D-Central puts on a dual 140 mm fan face, and it is the one to buy when the run matters more than the machine. A 200 mm duct is what the big metric inline fans mate with, what a shared plenum for several miners is built in, and what Avalon Q ducting uses.

200 mm is not 8 inches. Eight inches is 203.2 mm, which is why an imperial shroud and a metric hose never quite settle onto each other. This collar is drawn metric: 200.0 mm crest, 198.0 mm land.

The fan side takes both 140 mm fans on a 140.0 mm pitch with a 134.0 mm bore each and merges them inside a single PETG body before the transition begins.

What it fits: dual 140 mm exhaust on 200 mm metric duct

Miners with two 140 mm exhaust fans on a 140.0 mm pitch, exhausting into 200 mm metric duct. That is the S21 Pro and S21+ class and any other machine built with the same dual-140 face, with a 3.0 mm sealing land around each 134.0 mm bore.

For a flange drawn specifically to the S21 Pro chassis at the same outlet size, use the Antminer S21 Pro dual 140 mm to 200 mm metric duct shroud. On imperial ducting, use the universal dual 140 mm to 8-inch shroud at 203.2 mm. For a smaller metric run, step down to the dual 140 mm to 160 mm shroud.

How it installs

1. Set the flange over both 140 mm exhaust fans on the fan screw pattern.
2. Fix through the 5.0 mm holes and 5.424 mm slots with the miner’s large-head fan screws, or your own plus a 9 mm or larger flat washer under each head.
3. Slide 200 mm metric duct over the collar, past the 200.0 mm crest.
4. Clamp onto the 198.0 mm sealing land, support the duct close to the shroud, then continue to the inline fan, plenum or wall port.

Why the biggest collar in the line

Every part in a ducted exhaust has a pressure cost, and the sensible engineering aim is to make sure the cheap-to-fix parts are not the expensive ones. Duct length and bends are hard to avoid; collar diameter is not. Opening the exhaust to 200 mm at the machine means the transition is generous, the velocity through it is low, and whatever ends up limiting the run is somewhere you chose rather than a hole you were stuck with.

The transition is gradual rather than stepped. An abrupt expansion lets the flow separate from the wall and roll into a recirculating pocket at the corner, which costs pressure and adds noise; a body that opens progressively keeps the air attached to the wall through the change in section.

• Opens a dual-140 exhaust to 200 mm, the largest metric duct size in the range.
• Mates directly with 200 mm metric inline duct fans and Avalon Q ducting.
• Expands gradually so the flow stays attached rather than separating at a step.
• Cut for the dual-140 face: 140.0 mm pitch, 134.0 mm bore, 3.0 mm sealing land per fan.
• Clamps on a 198.0 mm land beneath a 200.0 mm crest, with no tape in the joint.
• Keeps 8.63 mm of driver clearance at the tightest fan screw across a 300 mm body.

Specifications

Open source: big parts, free files

A 300 by 200 mm shroud is a lot of plastic to send around the world, so D-Central Technologies publishes the design rather than hoarding it: our own drawing, ours end to end, released under CC BY-SA 4.0 at the 3D models download center, free to download, modify, print and sell. Its card is the dual 140 mm to 200 mm entry and the file is the dual-140 to 200 mm shroud bundle, with the STL, the CC BY-SA 4.0 licence and the installation and safety guide inside. If there is a printer near you, that is the sensible way to get one.

If not, this listing is the finished shroud, made to order in PETG in Montreal, Quebec, in black or the D-Central orange, and shipped from Canada. We do not charge for the drawing and never intend to; ordering the part, or funding us at the D-Central fund page, is what buys the bench time behind the next one.

Works with

• Antminer S21 Pro Dual 140 mm to 200 mm Metric Duct Shroud
• Dual 140 mm Fan to 160 mm Metric Duct Shroud
• Universal Dual 140 mm to 8″ Duct Shroud
• Antminer S19 / S21 Dual 120 mm to 200 mm Metric Duct Shroud
• 140 mm Intake Filter Ring

The full chain of parts is in the D-Central shroud and ducting system.

Frequently asked questions