6″ to 4″ Duct Reducer

Description

Overview

The small end of the reducer family. Tapers 6-inch duct down to 4-inch, which is the size that PSU exhausts, small enclosure fans and tight wall penetrations actually want.

What it fits

Standard 6-inch duct on the wide end, standard 4-inch on the narrow end. The 4-inch side matches the collar on our PSU exhaust shroud and the branches of the 6″ to dual 4″ Y-splitter.

Measure before you order. Fit dimensions in this line are derived from published fan and chassis geometry and are not yet validated against measured production hardware. Check your flange size and the clearance around your machine against the footprint in the specifications below. If something does not fit, tell us — that is how the next revision gets better.

How it is used

Use it to bring a 6-inch line down to a 4-inch dryer-vent-sized wall penetration, to feed a small inline fan, or to join a PSU line into a main run. It is also the fitting that lets an existing 4-inch house vent serve a mining exhaust without cutting new holes in the building.

Why it helps

Buildings are already full of 4-inch penetrations — dryer vents, bathroom fans, old range hoods. Being able to step down to that size cleanly means you can often reuse a hole that already exists instead of making a new one, which is frequently the difference between a project that happens and one that does not.

• Gradual taper from 6-inch to 4-inch
• Matches the 4-inch collar on the PSU shroud and Y-splitter branches
• Lets a mining exhaust reuse an existing 4-inch building penetration
• Single continuous body, no assembly

Specifications

Open source — print it yourself, or buy it finished

Every shroud D-Central designs is released as an open file. The geometry for this part is free to download from our 3D models download center: use it, modify it, remix it, run it in your own shop, sell what you make from it. There is no licence to buy and no design gated behind a purchase. Shared knowledge is the whole reason this industry has open hardware at all, and we are not going to be the ones who stop passing it on.

This listing is for the finished part: made to order in PETG and shipped from Montreal, Quebec. If you would rather have it in your hands than spend an evening making one, buy it here — that is what pays for the next design in the line. You can also support the open-source work directly through D-Central’s fund page.

Works with

• APW PSU Exhaust to 4″ Duct Shroud
• 6″ to Dual 4″ Y-Splitter
• 8″ to 6″ Duct Reducer
• 6″ Duct Coupler

See the full D-Central shroud and ducting system for the compatibility matrix and sizing guide.

Frequently asked questions