Antminer S21 Pro Dual 140 mm to 6″ Duct Shroud

Description

Antminer S21 Pro shroud: dual 140 mm fans into one 6-inch duct

This Antminer S21 Pro shroud takes the machine’s rear 140 mm fan pair and merges both fan columns into a single 6-inch duct collar, so the exhaust leaves as one directed stream you can point at a window, a wall penetration or a heat-recovery run.

The S21 Pro moved to a 140 mm fan pair. Almost every ASIC shroud in circulation is dimensioned to a 120 mm flange on the 105 mm screw square, which is simply the wrong pattern for this machine — buyers land on a dual-120 part constantly and find the fan frames sitting proud of the mouth. This body is drawn in-house around the 140 mm exhaust face instead, so both frames land inside the plenum where they belong.

It comes out of the shop as one continuous PETG body: no seams to open up under heat, no fasteners to back out, nothing to assemble on the bench.

What it fits: the S21 Pro 140 mm fan pair

Built for the Antminer S21 Pro, S21+ and S21 XP rear 140 mm fan pair, terminating in a 6-inch duct collar. It is not for the standard S21 or the S19 family — those run 120 mm fans and take the Antminer S19 / S21 Dual 120 mm to 6″ Duct Shroud. The check takes ten seconds: put a tape across the rear fan flange. 140 mm is this part; 120 mm is the dual-120 part.

If your ducting is metric, the same fan-side geometry terminates in a 200 mm collar as the Antminer S21 Pro Dual 140 mm to 200 mm Metric Duct Shroud. If you want more cross-section in imperial, take the Antminer S21 Pro Dual 140 mm to 8″ Duct Shroud.

How it installs

1. Seat the shroud over the rear fan pair so both 140 mm frames sit inside the plenum mouth.
2. Clamp 6-inch flexible or rigid duct onto the collar with a worm clamp.
3. Allow for the 292 mm span behind the machine before you push the rack back against the wall.
4. Run the duct to a window port, a wall penetration or an inline fan, and clamp every joint.

Why the plenum shape earns its price

Two fans firing into one round outlet will interfere with each other if they meet the collar independently — each column arrives at an angle, they collide in the throat, and part of what the fans just did is spent stirring air instead of moving it. The plenum on this body gives both 140 mm columns a shared volume to settle in before the section narrows to the 152.4 mm of a 6-inch round. The transition is a continuous curve, not a flat plate with a hole in it, so the air changes direction gradually rather than slamming into a step.

Material matters as much as shape here. PETG holds its geometry in ASIC exhaust heat, where PLA goes soft and a shroud slowly droops off the fan face over a summer.

• Merges both 140 mm fan columns into one plenum before the transition to round
• Terminates in a standard 6-inch collar sized for worm-clamped flex duct
• Separates exhaust from intake so the machine stops re-breathing its own heat
• Printed in PETG, which keeps its shape in exhaust heat that softens PLA
• Ships as one continuous body — no fasteners, no glued seams, no assembly
• Feeds the same 6-inch fittings as the rest of the D-Central ducting line

Specifications

Open source: print it yourself, or buy it finished

D-Central draws these bodies in-house and gives the designs away. The S21 Pro shroud geometry is released open source under CC BY-SA 4.0 at our 3D models download center — free to download, modify, remix, print and sell. No licence to buy, nothing gated behind a purchase.

This body is D-Central Technologies’ drawing of the S21 Pro exhaust face — measured here, drawn here, not a remix of somebody else’s file. Its card in the download centre links the ZIP, which holds the STL, the CC BY-SA 4.0 licence and the installation and safety guide.

What you are buying on this page is the finished part: made to order in black or orange PETG and shipped from Montreal, Quebec. The file costs nothing and always will — buying the printed body, or backing D-Central’s fund page, is what funds the next body in the line.

Works with

• Antminer S21 Pro Dual 140 mm to 8″ Duct Shroud
• Antminer S21 Pro Dual 140 mm to 200 mm Metric Duct Shroud
• 140 mm Intake Filter Ring
• 6″ Duct Coupler
• 6″ Window Exhaust Port

The full D-Central shroud and ducting system has the compatibility matrix and the sizing guide for the whole run.

Frequently asked questions