Shop ASIC Shrouds for Bitcoin Mining

ASIC miner shrouds: a sealed hood from the fan face to a duct collar

An ASIC miner shroud is a one-piece hood that seals over a miner's exhaust fan face and hands everything those fans move to a round duct collar, so the heat leaves the room down a duct instead of pooling behind the rack. This category holds D-Central's 45 shroud bodies — single 120 mm, dual 120 mm, single and dual 140 mm, stacked-fan Avalon faces, full-chassis wraps and metric-collar variants — every one of them drawn in-house around a specific exhaust geometry and produced as a single continuous PETG body with no seams, no fasteners and nothing to assemble on the bench.

Buying the right one is three decisions, and they are all answerable in about a minute with a tape measure and the back of your machine. What fan face does the miner present? What duct size does the run want? What do you want the collar to do when the duct has to come off?

Decision one: what fan face is on the machine

Fitment in this line is keyed to the fan, not the badge on the front, because manufacturers change a chassis far more often than they change a fan size. Put a tape across one exhaust fan flange. A 120 mm frame carries its four screws on a 105 mm square. A 140 mm frame carries them on a 124.5 mm square. That single measurement decides half the catalogue.

Two millimetres decides the Avalon. Canaan stacks its pair on a 122.0 mm vertical pitch where every dual-120 Antminer body sits on 120.0 mm, and a millimetre per side is more than a mounting slot absorbs — which is why the Avalon bodies are drawn separately, to that face, with a 116.0 mm bore per fan and a 2.0 mm sealing land around each.

One family is excluded on principle: hydro, immersion and water-cooled chassis. Bitmain abbreviates them Hyd and Hydro, they have no fan face at all, and no shroud in this category or any other will mount to one.

Decision two: 6-inch or 8-inch, and what to do about metric duct

Six inch is 152.4 mm nominal. Eight inch is 203.2 mm. Because open area goes with the square of the bore, an 8-inch collar carries roughly 1.8 times the cross-section of a 6-inch one, and that extra area is headroom the duct run spends on length, bends and anything else standing between the fan and the outside air.

• Take 6-inch when one machine runs a short, reasonably direct route: through a nearby wall, out an adjacent window, into the next room. It is the size every hardware store stocks in flexible hose, dryer-vent hardware and window kits, and the size common inline fans are built around.
• Take 8-inch when the run climbs, turns more than once, joins a shared trunk, or has an inline booster on it. Oversizing costs you shelf space. Undersizing costs airflow you already paid for at the wall socket.
• Take a metric collar if you buy ventilation in millimetres. 150 mm is not 6-inch — the 2.4 mm gap is exactly what turns a clamped joint into a taped one. The dual 120 mm to 150 mm metric shroud and its 160 mm and 200 mm siblings are cut for the hose you already own, with the crest at duct nominal and the clamp land 2.0 mm behind it.

The 120 mm versus 140 mm question answers itself at the machine, but it is worth knowing why it matters. A 140 mm rotor sweeps a wider disc than a 120 mm one, and the extra area sits at the outside of the blade where tip speed is highest. Push that fan through a body drawn for a 120 mm face and you block precisely the ring doing the most work; the air recirculates behind the plate and comes back at the fan instead of going down the duct.

Decision three: body style and collar style

Once the fan face and the duct size are settled, the remaining choices are about the room the machine lives in and how often you take the duct off.

Body styles

• Plain plenum — the workhorse. Both fan columns merge in a shaped volume, then the section rounds down to the collar. Two fans dropped straight into a round hole collide at the step and separate off its shoulder; a plenum gives them somewhere to become one stream first.
• Venturi — a contracting throat instead of a step, so accelerating air stays pressed to the wall through the transition. The Antminer S19 / S21 Venturi Shroud is the one to fit when the duct downstream is already working hard.
• Offset collar — the outlet moves off centre so the duct clears a wall, a shelf edge or a rack upright without an elbow in the first 200 mm.
• Full wrap — encloses the entire chassis exhaust end rather than the fan flanges alone, closing the corner and edge paths a fan-face body leaves open. The S19 wrap and the S17 wrap are the containment answer, at 296 mm and 304 mm across respectively.
• Wide base — a 260 mm mounting plate against the standard 250 mm, putting material outboard of the fan screws so a hanging duct loads the chassis face rather than levering on four slots.

Collar styles

• Plain flex-over collar — retention bead crest at 152.4 mm, clamp land at 150.4 mm behind it. Flex slides on, a worm clamp closes on the land, the bead is the mechanical stop.
• Clamp groove — a circumferential seat so the band cannot walk along the barrel.
• Bayonet — quarter-turn twist-lock, for a machine that comes out of the run often.
• Threaded — a coarse printed thread that takes either a duct receiver or a blank-off cap, so an idle machine seals instead of bleeding flow out of a shared trunk.
• Polished — every interface identical to the plain wide-base body, with the visible faces worked to an even sheen for a machine that sits where people can see it.

How a shroud goes on

1. Shut the machine down and clear the space behind the exhaust face.
2. Seat the body over the fan face so every fan mouth opens into the plenum, and refit on the stock fan screws. The flange slots are 6.40 × 5.00 mm; reuse the miner's own large-head fan screws, or put a 9 mm or larger flat washer under an M4 head.
3. Slide duct over the collar past the retention bead and land a worm clamp on the sealing band behind it.
4. Route the run out and carry its weight at the wall or the first bend, never on the collar.

Nothing on the miner changes. No hole is drilled, no connector is unplugged, no firmware is touched, the stock fans stay fitted, and the body lifts off in one movement. On the dual-120 bodies the shell is cut back around the screw heads so a driver reaches all eight with the duct still attached — the difference between a fan swap taking five minutes and taking an afternoon.

Why these are made to order in Montreal, Quebec

Every shroud here is printed for the order it belongs to, in PETG — black or D-Central orange — and shipped worldwide from Canada. That is how one shop keeps this many bodies and collar sizes alive at a single tolerance standard instead of warehousing a guess at which variant sells. It is also why the geometry keeps improving: a wide-base plate, a venturi throat or a metric crest can enter the line the week it is drawn rather than waiting out a container of the old shape.

PETG is the material for every body in this catalogue, offered in black and in D-Central orange. A shroud is nothing but dimensions, and the way this line protects them is geometry rather than assembly: one continuous body per part, no bonded joint, no fastener, no gasket. The collar, the mounting plate and the transition between them are the same piece of plastic. And every design in this line is D-Central's own drawing, released open source under CC BY-SA 4.0 at the 3D models download center — free to download, modify, print and sell. What this category sells is the finished part; the geometry was never the price of admission. D-Central's fund page backs the open work directly.

Frequently asked questions