Fan Shrouds

A fan shroud is a 3D-printed adapter that bolts over the fan of your ASIC miner and gives it a round port for a ducting hose or an inline fan — essentially a funnel that bundles the airflow instead of letting it blow freely into the room. That gets you three things: you route the waste heat exactly where you want it (outside, into an adjacent room, or into your heating), you feed the miner cooler air from outside, and you can convert it to external cooling — the most effective lever against the noise.

The shroud is mounted over the existing fan, or in its place when you convert to external cooling. Screws and a hose clamp are included.

Fan size and case decide. Antminer S19, S19 Pro, S19j, S19j Pro, S19k Pro, S19 XP, S19a and S19a Pro use 2× 120 mm fans — and so do the base S21 and the T21. They are covered by Antminer S19 / S21. The S21+, S21 Pro and S21 XP use 2× 140 mm fans and need the shrouds from Antminer S21+ / XP / PRO. The Antminer S9 and the Whatsminer range M20 to M70 each have their own subcategory.

And if you do not run an Antminer at all: the plain shrouds sit on the frame of the hashboard fan, so they fit many other machines as well. The hoods that also enclose the power supply exist for Bitmain miners only — there the PSU sits as a separate block next to the case, and other manufacturers build that differently.

A miner has an intake side and an exhaust side, and each side needs its own shroud. Start with the exhaust: that is where the hot air leaves, and a hose takes it outside or into the next room — biggest effect for the least effort. A second shroud on the intake side pays off when you want to draw in cooler air from outside or when you box the miner in; sets for both sides are available.

Two things to check first: if you draw in unfiltered room air, a dust filter keeps dust off the hashboards. And not every model has a fan on both sides — on the Antminer Z15 Pro, for example, both fans sit on the intake side and the exhaust side is a plain grille that a shroud cannot attach to.

On Bitmain miners the power supply sits as a separate block next to the hashboards and releases its heat into the room on its own. A shroud with a PSU adapter bridges the gap between hashboard fan and power supply and encloses both areas: on the exhaust side all of the heat — hashboards and PSU — goes into the hose, on the intake side the power supply gets fresh air as well.

That is worth it wherever the heat has to leave the room completely: living space, box, cabinet. On the S19 line you pick the PSU distance that matches your model; on the S21+ models the adapters are included.

The diameter of the shroud sets the hose. 4 inch (100 mm) exists for the Antminer S9 only. 6 inch (150 mm) is compact and enough for short, straight runs. 8 inch (200 mm) is the common size for standard setups and matches most inline fans. 10 inch (250 mm) has the lowest air resistance.

The larger the cross-section, the less the fan has to work against back pressure — it spins slower and therefore runs quieter. That pays off above all with hose runs longer than two meters, with bends, and in continuous operation. Matching aluminium flex ducts are in ducting hoses; shroud and hose have to match in diameter.

A shroud with a hose already takes away a good part of the noise, because the exhaust no longer blows freely into the room. It gets substantially quieter only without the stock fans: an intake adapter takes their place, and an inline fan is plugged straight into it — moving the same amount of air at a much lower speed. This combination of shroud, inline fan and spoofer is exactly what people mean by a silent kit or an S19k Pro silent conversion.

So the miner does not report a fan error and throttle, you need a fan spoofer under Bitmain stock firmware; under Braiins OS or another alternative firmware you can switch off fan monitoring in software instead. If you additionally put the miner in a box or in the cellar, you route intake and exhaust air outside through one hose each — the shrouds are the connection point for that. One rule applies: as much air has to be able to flow in as flows out.

PETG is temperature-resistant and keeps its shape where the exhaust of an ASIC miner gets warm in continuous operation — which is why it is the material for all of our shrouds. They are printed as solid material, not as a thin shell: the shroud holds the attached hose and its clamp without warping. Designed and manufactured in our own production in Germany; mounting hardware is included with every shroud, and you need nothing more than a screwdriver.