120 mm to 140 mm Fan Adapter

Description

120 mm to 140 mm fan adapter — a bigger fan on a stock 120 mm mount

This 120 mm to 140 mm fan adapter bolts a 140 mm fan onto a 120 mm fan position on an ASIC miner. The chassis side carries the standard 120 mm bolt square; the outer face carries the standard 140 mm bolt square. The direction is worth stating flatly, because it is the one thing people get wrong when they order: your machine keeps its 120 mm holes, and the fan you add is the bigger one.

The reason to want that is noise. A 140 mm rotor sweeps roughly 36 percent more frontal area than a 120 mm rotor, so it can move the same volume of air while turning slower — and fan noise climbs steeply with tip speed. Fitting a larger fan and then running it lower is the most effective acoustic change available to a home miner who is not willing to build a sealed enclosure around the machine.

It is also how a mixed fleet gets standardised: put an adapter on each 120 mm machine and every shroud, filter ring and duct part you buy after that can be a 140 mm part, one size of spare on the shelf instead of two.

What it fits

Standard 120 mm fan mounting on the chassis face, standard 140 mm fan mounting on the outer face, with a shaped transition between the two apertures rather than a flat plate with a hole cut in it. It suits any machine or enclosure built around a 120 mm fan position: Antminer S9-class and S19-class chassis, single-fan cases, workshop rigs and ducted home builds.

The footprint is 140 × 140 × 28 mm. Plan for that depth plus the thickness of the fan you are adding when you lay out clearance behind the machine.

If you need the opposite direction — a 120 mm fan sitting on a 140 mm fan position — that is the 140 mm to 120 mm Fan Adapter: same construction, mirrored geometry. If you want to filter the 120 mm face instead of enlarging it, the 120 mm Intake Filter Ring is the part for that.

How it installs

1. Unbolt the existing 120 mm fan from the machine.
2. Bolt the adapter to the 120 mm fan position, small aperture against the chassis.
3. Bolt your 140 mm fan to the outer face.
4. Plug the fan into the machine’s fan header and set your speed curve.
5. Bring the speed down until the room is quieter, then watch chip temperatures for a day before you settle on a curve.

Why the shaped transition matters

A flat plate with a 120 mm hole and a 140 mm bolt square is easy to make and it wastes the fan you just bought. The outer third of a 140 mm rotor is where most of the air is being moved, and a flat plate throws that outer air straight at a step face where it separates, swirls and turns into noise instead of flow. This adapter carries a continuous curved wall from the 140 mm aperture down to the 120 mm one, so the air is turned rather than stopped.

The body comes out as one continuous piece of PETG: no glued seam to open up, no fasteners holding two halves together, nothing to rattle at fan frequency. PETG is the right material at a fan face because it keeps its stiffness in the warm air around a running miner, where PLA goes soft.

• Bolts a 140 mm fan to a stock 120 mm position with no chassis modification
• Turns the air on a curved transition wall instead of a flat plate step
• Opens up 140 mm fan choice, so the same airflow can arrive at a lower fan speed
• Standardises a mixed fleet onto one shroud size and one filter size
• Comes out as a single continuous PETG body — no assembly, no fasteners
• Adds a known 28 mm of depth, so clearance is simple to plan

Specifications

Open source — print it yourself, or buy it finished

D-Central Technologies designed this adapter, drew the 120 mm and 140 mm bolt squares and the wall that joins them, and open-sourced the result. Ours — not a remix, not somebody else’s file wearing our name. The geometry is published free under CC BY-SA 4.0 at our 3D models download center, and this part has its own card at the 120 mm to 140 mm fan adapter entry: print it, cut it about, fit it to a chassis we have never seen, sell what you make from it.

Take the file directly — the 120-to-140 adapter bundle holds the STL, the CC BY-SA 4.0 licence and the installation and safety guide, and nothing in it is gated behind a purchase.

What this listing buys is the finished part: made to order in PETG, black or D-Central orange, and shipped from Montreal, Quebec, so you can spend the evening mining instead of making. The STL stays free whatever you decide; buying the printed one, or backing the work at D-Central’s fund page, is what pays for the next adapter size we draw.

Works with

• 140 mm to 120 mm Fan Adapter
• 140 mm Intake Filter Ring
• Whatsminer 140 mm Fan to 6″ Duct Shroud
• Universal Dual 140 mm to 6″ Duct Shroud
• 120 mm Intake Filter Ring

The whole chain — fan face, shroud, coupler, elbow, window port — is laid out in the D-Central shroud and ducting system.

Frequently asked questions