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.
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 The classic home-mining machine. The dedicated S9 body wraps 150 mm of the exhaust end rather than sitting flat on the fan. S9 variants rehoused in a different enclosure are outside it. | 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 Runs hot with thin thermal margin, so this one gets a full-wrap body and the largest duct you can fit. The S17e and the S17+ sit outside it — different exhaust face. | 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 / S19 XP The most shrouded machine in mining. Both a fan-face body and a deeper full-wrap body are drawn for it, so you can pick how much of the chassis end you capture. | 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, air-cooled) Shares the dual-120 arrangement with the S19. Not the S21 Pro, the S21+, the S21 XP or the S21 Hydro — 120 mm fans here, 140 mm on the other three, no fan face at all on the Hydro. | 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 / S21+ / S21 XP These three moved to a 140 mm pair on one shared exhaust face, so the S21 Pro body is the part for all of them — and no dual-120 shroud fits any of them. Hydro and immersion variants have no fan face at all. | 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 M30S+ / M50 / M50S+ / M60 Drawn to the 140 mm fan flange these four share. Not the M10, M20, M31S or M32 — those use a different chassis face. | 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 |
| Canaan Avalon A15 / A15XP The A15 stacks its two 120 mm fans vertically at a 122.0 mm pitch — 1 mm per side beyond what a standard dual-120 shroud can absorb, so it gets dedicated parts drawn from the A15XP interface. Other Avalon families are not covered. The 200 mm version matches the Avalon kit’s own metric ducting. | 2 × 120 mm (vertically stacked) | Avalon A15 Vertical Dual 120 mm to 6-Inch Duct Shroud $35.99 | Avalon A15 Vertical Dual 120 mm to 8-Inch Duct Shroud $41.99 | — |
| 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 | — |
Picking the right one. Every shroud in this line is drawn around the machine's own exhaust geometry — fan size, screw pitch and chassis face — and each product page carries the full footprint and collar size. Match your machine, your fan size and your duct diameter and the matrix above lands you on the right part. If you are between two of them, tell us what you are running and we will point you at it.
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 $17.99. 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.
What the chamber does. A reactive expansion chamber works on a change in cross-section: part of the sound energy travelling down the air column meets the step and is reflected back toward the source instead of riding the duct into the next room. The v2 bodies add a quarter-wavelength side branch on top of that, tuned to the tonal blade-pass region a fan produces. Textbook duct acoustics, executed as a single printed piece — no lining, no fibre, nothing to shed into the airstream over time.
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.
- Universal Single 120 mm Fan to 6" Duct Shroud
- Universal Single 120 mm Fan to 8" Duct Shroud
- Antminer S9 Single 120 mm to 6" Duct Shroud
- Whatsminer 140 mm Fan to 6" Duct Shroud
- Whatsminer 140 mm Fan to 8" Duct Shroud
- Antminer S19 / S21 Dual 120 mm to 6" Duct Shroud
- Antminer S19 / S21 Dual 120 mm to 8" Duct Shroud
- Antminer S19 / S21 Venturi Shroud — Dual 120 mm to 6"
- Antminer S19 / S21 Offset Shroud — Dual 120 mm to 6"
- Antminer S19 / S21 Clamp-Groove Shroud — Dual 120 mm to 6"
- Antminer S19 / S21 Bayonet-Lock Shroud — Dual 120 mm to 6"
- Antminer S19 / S21 Threaded-Collar Shroud — Dual 120 mm to 6"
- Antminer S21 Pro Dual 140 mm to 6" Duct Shroud
- Antminer S21 Pro Dual 140 mm to 8" Duct Shroud
- Universal Dual 140 mm to 6" Duct Shroud
- Universal Dual 140 mm to 8" Duct Shroud
- Antminer S19 Full-Wrap Dual 120 mm to 6" Shroud
- Antminer S19 Full-Wrap Dual 120 mm to 8" Shroud
- Antminer S17 Full-Wrap Dual 120 mm to 6" Shroud
- Antminer S17 Full-Wrap Dual 120 mm to 8" Shroud
- Avalon A15 Vertical Dual 120 mm to 6-Inch Duct Shroud
- Avalon A15 Vertical Dual 120 mm to 8-Inch Duct Shroud
- Avalon A15 Vertical Dual 120 mm to 200 mm Metric Duct Shroud
- Antminer S19 / S21 Dual 120 mm to 150 mm Metric Duct Shroud
- Antminer S19 / S21 Dual 120 mm to 160 mm Metric Duct Shroud
- Antminer S19 / S21 Dual 120 mm to 160 mm Metric Duct Shroud (Wide Base)
- Antminer S19 / S21 Dual 120 mm to 200 mm Metric Duct Shroud
- Dual 140 mm Fan to 150 mm Metric Duct Shroud
- Dual 140 mm Fan to 160 mm Metric Duct Shroud
- Dual 140 mm Fan to 200 mm Metric Duct Shroud
- Antminer S21 Pro Dual 140 mm to 200 mm Metric Duct Shroud
- Whatsminer 140 mm Fan to 150 mm Metric Duct Shroud
- Whatsminer 140 mm Fan to 160 mm Metric Duct Shroud
- Whatsminer 140 mm Fan to 200 mm Metric Duct Shroud
- Antminer S19 / S21 Dual 120 mm to 6-Inch Shroud — Wide Base
- Antminer S19 / S21 Dual 120 mm to 6-Inch Venturi Shroud — Wide Base
- Antminer S19 / S21 Dual 120 mm to 6-Inch Offset Shroud — Wide Base
- Antminer S19 / S21 Dual 120 mm to 6-Inch Clamp-Groove Shroud — Wide Base
- Antminer S19 / S21 Dual 120 mm to 6-Inch Bayonet Quick-Release Shroud — Wide Base
- Antminer S19 / S21 Dual 120 mm to 6-Inch Threaded Shroud — Wide Base
- Antminer S19 / S21 Dual 120 mm to 8-Inch Shroud — Wide Base
Silencers Shrouds with a reactive acoustic chamber between the fans and the duct.
- Single 120 mm to 6" Expansion-Chamber Shroud Silencer
- Whatsminer 140 mm to 8" Expansion-Chamber Shroud Silencer
- Antminer S19 / S21 Dual 120 mm to 6" Expansion-Chamber Shroud Silencer
- Antminer S19 / S21 Dual 120 mm to 8" Expansion-Chamber Shroud Silencer
- Antminer S19 / S21 Dual 120 mm to 6" Shroud Silencer v2 — λ/4 Side-Branch
- Antminer S19 / S21 Dual 120 mm to 8" Shroud Silencer v2 — λ/4 Side-Branch
Ducting & fittings Reducers, couplers, elbows, splitters and wall or window terminations.
- 8" to 6" Duct Reducer
- 6" to 4" Duct Reducer
- 6" Duct Coupler
- 8" Duct Coupler
- 6" 45° Duct Elbow
- 8" 45° Duct Elbow
- 6" 90° Duct Elbow (Compact)
- 8" 90° Duct Elbow (Compact)
- 6" Window Exhaust Port
- 8" Window Exhaust Port
- 6" to Dual 4" Y-Splitter
- 8" to Dual 6" Y-Splitter
- Bayonet Duct Receiver 6-Inch — Twist-Lock Duct Adapter
- Threaded Duct Receiver 6-Inch — Screw-On Duct Adapter
- 6-Inch Flex Duct Adapter — Rigid Socket to Flex Collar
- 8-Inch Flex Duct Adapter — Rigid Socket to Flex Collar
- 6-Inch Flex Duct Window Vent Port
- 8-Inch Flex Duct Window Vent Port
- 8-Inch Long-Radius 90° Airflow Duct Elbow
Accessories Fan adapters, intake filter rings and blanking caps.
What they are made of
The whole line is PETG, in black or D‑Central orange. Same geometry either way — the colour is yours to pick. Orange is our own colour, and a bright collar is easy to find behind a rack at arm's length in a dim room; black disappears into a living space. Every shroud, silencer, fitting and accessory in the system uses the same material, so a run you build out of several parts looks like one object rather than a collection.
Every part is a single continuous body — no glued joints, no fasteners, no bonded seam, nothing to assemble on the bench. That matters more than it sounds: a bonded shroud fails at the joint, and this line has no joint. It also means no gasket to perish and no fixing to back out at blade-pass frequency.
Made to order in Montreal, Quebec, and shipped worldwide.
All of it is open source
We drew every part in this system. All 72 of them are D‑Central's own work, and all 72 are released as open files under Creative Commons BY‑SA 4.0 at our 3D models download centre. 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, no email wall, and no design held back behind a purchase. Every card in the catalogue above links straight to its own file.
Four multi-model archives are there too, for people who want a whole machine family in one go: the Antminer full-wrap pack, the S21 pack, the Whatsminer 140 mm pack and the Avalon A15 pack.
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, black or orange, and shipped from Montreal, Quebec — and what they pay is what funds the next design in the line. The files stay free either way. If the open work is worth something to you and you are not buying a part, back it directly through the D-Central fund.
Airflow guides from the workshop
The shroud is one part of a system. These guides cover the rest of it — sizing the duct, getting it out of the building, and what a silencer adds.
- ASIC miner shrouds: the complete guide
- 6-inch vs 8-inch duct: the real sizing guide
- How to vent a miner out a window (properly)
- ASIC miner silencers: what the physics says
- The intake side: dust filters and fan swaps
- Whatsminer ducting: why 120 mm shrouds do not fit
- Avalon airflow: the 122 mm fan-pitch problem
Frequently asked questions
How much quieter will a shroud make my miner?
A plain shroud 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 go further: a reactive expansion chamber works on the sound itself, and the v2 bodies add a quarter-wave side branch tuned to the tonal blade-pass region a fan produces. Combine a shroud, a sensible duct run and some distance and you end up with a machine you can share a building with.
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.
Which S21 takes which shroud?
The standard air-cooled S21 carries a 120 mm fan pair and takes the dual-120 bodies. The S21 Pro, the S21+ and the S21 XP all moved to a 140 mm pair on one shared exhaust face, so all three take the S21 Pro dual-140 body. The Hydro has no fan face at all and no shroud applies to it. Fan size, not model badge, is what decides it.
How do I know which part is mine?
By geometry. Every product page states the fan pattern the body seats on, the screw pitch, the collar diameter and the full footprint in millimetres, and the compatibility matrix above names the machines each body is drawn for. Match the fan size and the duct diameter and you are on the right part. If your machine is not named, it is not covered — a family name is not a fitment claim, and we do not make one we did not draw. Tell us what you are running and we will point you at the right body.
Can I really just download the files and make them myself?
Yes. Every one of them, free, at the 3D models download centre, under CC BY-SA 4.0. You can modify them, share them, and sell what you make from them. Each model has its own archive, and there are four multi-model packs for whole machine families. Buying the finished part here is a convenience we offer, not a condition of getting the design.
What are they made of, and what colours?
PETG, in black or D-Central orange — the same part either way, so pick the one that suits where the machine lives. 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.
What about the power supply's own heat?
A PSU is a meaningful fraction of your total room heat, and this line does not have a part that mounts to one. There is no PSU shroud in the system today. What the system does give you is a Y-splitter $38.99, so a second airflow source can join the miner's trunk line and leave through one wall penetration instead of two.
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.