Open Source

ASIC Shrouds & Duct Adapters

A complete system for getting mining heat out of the room it is in — shrouds, silencers, ducting and fittings. Every design is open source and free to download. If you would rather buy the finished part than make it, we sell it here.

47 Parts

100% Open source

1 Piece each — no assembly

Find your shroud Download the files

What a shroud actually does

A mining machine is a heater that happens to do arithmetic. Left alone, it dumps that heat in every direction at once, into whatever room it is standing in, and radiates fan noise the same way. A shroud captures the exhaust and hands it to a duct — which turns an uncontrolled heat source into a single, steerable output you can point at a window, a workshop, a greenhouse, or a heat-recovery loop.

That one change is what separates a machine you tolerate from one you can place deliberately. It is also the precondition for almost everything else people want to do with mining heat: heating a garage, warming a greenhouse, running a machine in a house without losing a room to it.

Every part in this system is designed and produced by D-Central, released as an open file, and made as a single continuous body — no glued joints, no fasteners, nothing to come apart after a few thousand heat cycles.

Find your shroud

Start with your machine. The 6-inch column is the compact choice for short, direct duct runs; the 8-inch column is the one to take whenever the run is long, has several bends, feeds an inline booster fan, or is shared with another machine.

Machine	Exhaust fans	6″ duct	8″ duct	Quieter option
Antminer S9 / S9i / S9j / S9k / S9 SE The classic home-mining machine. Dedicated S9 body wraps the exhaust end rather than sitting flat on the fan.	1 × 120 mm	Antminer S9 Single 120 mm to 6" Duct Shroud $24.99	Universal Single 120 mm Fan to 8" Duct Shroud $24.99	Single 120 mm to 6" Expansion-Chamber Shroud Silencer $43.99
Antminer S17 / S17 Pro / S17+ / T17 / T17+ Runs hot with thin thermal margin. Full-wrap capture and the largest duct you can fit are both worth it here.	2 × 120 mm (rear pair)	Antminer S17 Full-Wrap Dual 120 mm to 6" Shroud $57.99	Antminer S17 Full-Wrap Dual 120 mm to 8" Shroud $60.99	Antminer S19 / S21 Dual 120 mm to 6" Expansion-Chamber Shroud Silencer $57.99
Antminer S19 series The most shrouded machine in mining. Fan-face, full-wrap and PSU spill-lip options all exist for it.	2 × 120 mm (rear pair)	Antminer S19 Full-Wrap Dual 120 mm to 6" Shroud $57.99	Antminer S19 Full-Wrap Dual 120 mm to 8" Shroud $60.99	Antminer S19 / S21 Dual 120 mm to 6" Expansion-Chamber Shroud Silencer $57.99
Antminer S21 (standard) Shares the dual-120 arrangement with the S19. Not the same as the S21 Pro — check your fan size.	2 × 120 mm (rear pair)	Antminer S19 / S21 Dual 120 mm to 6" Duct Shroud $35.99	Antminer S19 / S21 Dual 120 mm to 8" Duct Shroud $41.99	Antminer S19 / S21 Dual 120 mm to 6" Shroud Silencer v2 — λ/4 Side-Branch $65.99
Antminer S21 Pro Moved to 140 mm fans, which makes every dual-120 shroud useless for it. Not the S21 XP — that machine is not covered.	2 × 140 mm (rear pair)	Antminer S21 Pro Dual 140 mm to 6" Duct Shroud $57.99	Antminer S21 Pro Dual 140 mm to 8" Duct Shroud $63.99	—
Whatsminer M-series (M20 / M30 / M50 / M60) Dimensioned to the bare M-series fan flange, so it carries across generations better than a chassis-specific part.	1 × 140 mm	Whatsminer 140 mm Fan to 6" Duct Shroud $30.99	Whatsminer 140 mm Fan to 8" Duct Shroud $35.99	Whatsminer 140 mm to 8" Expansion-Chamber Shroud Silencer $52.99
Any single 120 mm fan (custom / bench / enclosure) References the fan flange only. The fallback for anything without a dedicated part.	1 × 120 mm	Universal Single 120 mm Fan to 6" Duct Shroud $21.99	Universal Single 120 mm Fan to 8" Duct Shroud $24.99	Single 120 mm to 6" Expansion-Chamber Shroud Silencer $43.99
Any dual 140 mm fan pair (custom / rebuild / converted) Fits by fan pattern rather than chassis. Also the part for machines converted to 140 mm fans.	2 × 140 mm	Universal Dual 140 mm to 6" Duct Shroud $49.99	Universal Dual 140 mm to 8" Duct Shroud $54.99	—
Bitmain APW PSU (APW3 / APW7 / APW9) The heat everyone forgets. 4-inch is correctly matched to PSU-level airflow.	PSU exhaust face	APW PSU Exhaust to 4" Duct Shroud $19.99	—	—

Measure before you order. Fit dimensions across this line are derived from published fan and chassis geometry, not yet from measured production hardware. Check your fan flange size and the clearance around the machine against the footprint listed on each product page. If something does not fit, tell us — that is how the next revision gets better, and the open file means you can adjust it yourself in the meantime.

6-inch or 8-inch?

Duct diameter is the cheapest airflow you will ever buy. Every elbow, reducer and metre of flexible duct takes static pressure away from the fan, and a machine running at full power has none to spare. The only real cost of oversizing duct is the space it takes up.

Take 6-inch when

The duct goes more or less straight out a nearby wall or window
The run is short and has at most one gentle bend
The machine has a single fan
Space behind the machine is genuinely tight

Take 8-inch when

The run has real length, or climbs, or turns more than once
An inline booster fan is doing part of the work
Two machines share a trunk line
The machine has a dual fan pair running hard
You are adding a silencer, which is a restriction of its own

Reduce late, not early. If the hole you have to exit through is smaller than your trunk, keep the trunk generous and step down at the very last fitting with a 8″ to 6″ reducer $13.99. Reducing at the shroud and then running ten metres of narrow duct is the layout to avoid.

Shroud, or shroud with a silencer?

A plain shroud changes where the noise goes. A silencer tries to reduce the noise itself, by passing the air through a reactive expansion chamber — a deliberate change in cross-section that reflects part of the sound energy back toward the source instead of letting it ride the air column down the duct. The v2 designs add a tuned quarter-wavelength side branch on top of that, aimed at the tonal blade-pass component that fans produce.

We publish no decibel figures, because we have not measured any. These designs have not been on an acoustic bench. What an idealised expansion chamber of this size predicts is a modest single-digit transmission loss — useful, not transformative — and the v2 side branch predicts a deeper notch around its tuned frequency. Those are model outputs, not measurements, and we would rather say so than put a number on a box. Anyone quoting you a large decibel figure for a printed plastic chamber is selling, not measuring.

Silencers are also physically much larger than plain shrouds and cost you some airflow. If your machine is thermally marginal or your duct run is already long, take the plain shroud and solve the noise with placement, distance and isolation instead.

Five ways to mount the same shroud

For the Antminer S19 and standard S21 dual-120 platform we ship five variants of the same airflow body. They move the same air from the same fans; what changes is how the shroud attaches and how the collar terminates. Real installs are constrained by architecture, not by symmetry.

Style	Pick it when	Part
Venturi	Contracting throat instead of a hard step to the collar. The airflow-first choice.	Antminer S19 / S21 Venturi Shroud — Dual 120 mm to 6" $41.99
Offset	Collar moved off centre to clear a shelf, wall or rack upright — often removes an elbow from the run.	Antminer S19 / S21 Offset Shroud — Dual 120 mm to 6" $35.99
Clamp-groove	Dedicated band-clamp seat with a reinforcing band. The strongest joint, for vertical runs and machines that get moved.	Antminer S19 / S21 Clamp-Groove Shroud — Dual 120 mm to 6" $38.99
Bayonet	Quarter-turn on and off, no tools. For installs where the duct comes off regularly.	Antminer S19 / S21 Bayonet-Lock Shroud — Dual 120 mm to 6" $38.99
Threaded	Screw-on collar that accepts a blanking cap. The base of a modular, reconfigurable exhaust stack.	Antminer S19 / S21 Threaded-Collar Shroud — Dual 120 mm to 6" $38.99

The full system

Every collar in the line uses the same standard duct sizes, so any shroud connects to any fitting. Build the exhaust path you actually need.

Shrouds Fan or chassis capture, terminating in a standard duct collar.

Silencers Shrouds with a reactive acoustic chamber between the fans and the duct.

Ducting & fittings Reducers, couplers, elbows, splitters and wall or window terminations.

Accessories Fan adapters, intake filter rings and blanking caps.

In development Designed or specified, not yet finished. Each one is waiting on a real measurement or a solved mechanism rather than on effort — we would rather publish nothing than publish a fit dimension we have not verified.

All of it is open source

Every shroud, silencer and fitting in this system is released as an open file at our 3D models download center, under Creative Commons BY-SA 4.0. Download them, make them, modify them, remix them, run them in your own shop, sell what you make. There is no licence to buy, no signup, and no design held back behind a purchase.

That is not a marketing position, it is how this industry got anywhere. Open hardware and open firmware are the reason a person can build a miner on a bench at all, and we are not going to be the ones who stop passing it on. If you improve one of these designs, we would genuinely like to see it.

So why sell them? Because not everyone wants to spend an evening making a part they need today. This shop is for the people who would rather have the finished thing in their hands — made to order in PETG and shipped from Montreal, Quebec — and what they pay is what funds the next design in the line. If the open work is worth something to you and you are not buying a part, you can back it directly through the D-Central fund.

Download the files Fund the open-source work

Frequently asked questions

How much quieter will a shroud make my miner?

A plain shroud does not make a machine quieter so much as it changes where the noise goes — which, in practice, helps a great deal, because it lets you put the loud end somewhere other than where you are. The silencers add a reactive chamber that targets the noise itself, but we have not measured any of these designs on an acoustic bench and we publish no decibel figures. Expect modest, not miraculous.

Will a shroud make my miner run hotter?

A well-sized duct run should not. A badly sized one will. Every elbow, reducer and metre of flexible duct is a restriction the fan has to overcome, and if you stack enough of them — especially with a silencer in the path — you can push a machine into throttling. Size the duct generously, keep the bends gentle, and watch your chip temperatures for the first day after any change.

What is the difference between a 6-inch and an 8-inch shroud?

Only the outlet collar. The fan-side fit is identical. Take 6-inch for short, direct runs and 8-inch whenever the run is long, bendy, boosted or shared. If you have to exit through a smaller hole, keep the trunk large and reduce at the very last fitting.

Do these fit the Antminer S21 XP?

No. The S21 XP is not covered by this line. The standard S21 uses a 120 mm fan pair and takes the dual-120 shrouds; the S21 Pro uses a 140 mm pair and has its own part. Check the fan size on your machine before ordering — confusing the three is the most common mistake in the S21 range.

Is the fit guaranteed?

No, and we would rather say so plainly. Fit dimensions come from published fan and chassis geometry and have not yet been validated against measured production hardware. Measure your flange and your clearance against the footprint on each product page before ordering. If a part does not fit, tell us: that feedback drives the next revision, and because the file is open you can adjust it yourself immediately.

Can I really just download the files and make them myself?

Yes. All of them, free, at the 3D models download center, under CC BY-SA 4.0. You can modify them, share them, and sell what you make from them. Buying the finished part here is a convenience we offer, not a condition of getting the design.

What are they made of?

PETG, chosen for its tolerance of sustained warmth on the exhaust side of a machine. Every part is a single continuous body — no glued joints, no fasteners, nothing to work loose over thousands of heating and cooling cycles.

How long until my order ships?

Each part is made to order rather than pulled off a shelf, so there is a genuine lead time. That is the trade-off of a build-to-order shop: you get a part made properly rather than one that has been sitting in a warehouse, and you wait a little for it.

Can I duct the power supply too?

Yes, and most people forget to. A PSU is a meaningful fraction of your total room heat and usually sits somewhere with worse airflow than the miner. The APW PSU exhaust shroud $19.99 captures it, and a Y-splitter $38.99 merges it into your main duct so you only need one wall penetration.

Where do I send the heat?

Outside is the simple answer, but rarely the best one. A workshop, a garage, a greenhouse or a heat-recovery loop all turn a cost into something useful. Our miner heat reuse hub covers the practical options and the things worth knowing before you plumb mining exhaust into a space people occupy.