140 mm to 120 mm Fan Adapter

Description

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

This 140 mm to 120 mm fan adapter puts a 120 mm fan onto a 140 mm fan position. The chassis side carries the standard 140 mm bolt square, the outer face carries the standard 120 mm bolt square, and it is the mirror image of its sibling part — so read the direction twice before you add to cart. The machine you are fitting it to has 140 mm holes. The fan you are bolting on is the smaller one.

This is a logistics part more than an acoustics part. The 120 mm fan market is enormous: every speed, every bearing type, every static-pressure rating, on a shelf somewhere near you. The 140 mm market is a fraction of that. When a 140 mm fan dies on a Friday and the replacement is three weeks out, this adapter and a 120 mm fan from the local supplier have the machine hashing again by Saturday.

The second reason is specification. Some of the strongest high-static-pressure industrial fans are made only in 120 mm, and a hashboard stack is exactly the kind of restricted path those fans exist for. This part is how you get one onto a 140 mm face.

What it fits

Standard 140 mm fan mounting against the chassis, standard 120 mm fan mounting on the outer face, joined by a shaped transition rather than a flat blanking plate. That covers Whatsminer-class hardware and anything else built around a 140 mm fan position: large-fan enclosures, 140 mm workshop rigs, custom ducted builds.

The footprint is 140 × 140 × 28 mm, so budget that depth plus your fan thickness at the fan face.

Going the other way — putting a 140 mm fan onto a machine with 120 mm holes, usually to run it slower and quieter — is the 120 mm to 140 mm Fan Adapter. The two parts are not interchangeable, so pick the one that matches the holes already in your chassis.

How it is used

1. Remove the failed or unwanted 140 mm fan.
2. Bolt the adapter to the 140 mm fan position, wide aperture against the chassis.
3. Bolt the 120 mm fan to the outer face.
4. Connect it to the machine’s fan header and set a curve that matches the airflow the machine expects.
5. Expect to run the smaller fan faster than the 140 mm it replaced, and check chip temperatures once it settles.

Why the transition is shaped, not flat

Reducing a 140 mm opening to a 120 mm fan with a flat plate creates a sudden step in the airflow path, and a sudden step is where air separates from the wall, recirculates and starts making noise. The adapter instead carries a continuous curved wall between the two apertures, so the column of air narrows gradually into the smaller fan rather than slamming into a face.

It also matters that the whole thing is one piece of PETG. There is no bonded joint to creep in the warm air at a running miner’s fan face, and no bolted seam to buzz at blade-pass frequency. PETG stays stiff at temperatures that make PLA go soft, which is why the entire line is made from it.

• Fits a 120 mm fan to a 140 mm fan position with no chassis modification
• Turns a repair from a three-week wait into a same-week fix using stock 120 mm fans
• Unlocks high-static-pressure 120 mm fans that have no 140 mm counterpart
• Guides the airflow on a curved wall instead of stepping it down at a flat plate
• Single continuous PETG body — no assembly, no fasteners, no glued joints
• Known 140 × 140 × 28 mm footprint for clearance planning

Specifications

Open source — print it yourself, or buy it finished

The geometry behind this adapter is D-Central Technologies’ own work — we drew it, we measured it, we published it — released under CC BY-SA 4.0 at the 3D models download center, with its own card at the 140 mm to 120 mm fan adapter entry. Modify it, scale it to a fan face this line does not cover, run a batch and sell them — that is what the licence is for. Open hardware got this industry its repair culture; we are not going to be the ones who stop passing it on.

Go straight to the 140-to-120 adapter bundle: one download carrying the STL, the CC BY-SA 4.0 licence and the installation and safety guide.

Buying here gets you the part finished: made to order in PETG, black or orange, shipped from Montreal, Quebec, on a machine that is already down and waiting for a fan. The drawing costs nothing and stays that way — a purchase, or a direct gift at D-Central’s fund page, is simply what funds the next mirrored geometry in the range.

Works with

• 120 mm to 140 mm Fan Adapter
• 120 mm Intake Filter Ring
• Whatsminer 140 mm Fan to 8″ Duct Shroud
• Universal Single 120 mm Fan to 6″ Duct Shroud
• 140 mm Intake Filter Ring

Everything from the fan face to the window port lives in the D-Central shroud and ducting system.

Frequently asked questions