3D Printer Enclosure Air Filter – Tool-Free Slide-Out Cartridge (Carbon/HEPA)

A compact air filter for 3D printer enclosures, with a filter cartridge you can swap without tools. It's built for gentle, continuous cleaning: enough airflow to scrub the fumes, not so much that it warps prints or disturbs filament stored inside the enclosure.

Why I made it

I keep my filament inside the printer enclosure and mostly print TPU, PETG, ASA and PC. I needed a way to clean the air without creating strong drafts. I run it in the enclosure of my Prusa MK3S+.

How it works

• A 120 × 32 mm blower in the fan case pulls air in through the inlet grille.

• The air is pushed through the filter cartridge and out the other side.

• The cartridge slides in and out on printed rails. No tools needed to change the filter.

Filter media

The cartridge takes any filter material up to 28 mm thick. I use activated carbon sheets cut from a household air purifier filter. HEPA, cut pieces of HVAC furnace filter, or a combination also work.

Loose activated carbon pellets work too. Hold them between two thin sheets of filter material, or put them in a fine mesh bag, so the granules stay in the cartridge. Use acid-free (not acid-washed) 3–4 mm pellets, like the carbon sold for Nevermore filters. Acid-washed carbon can corrode metal parts inside the enclosure.

Mounting

Screw the fan case to the inside of the enclosure, or stick it on with strong double-sided tape. Mount it as high as you can, on the ceiling or near the top of a wall: warm air from the bed and hotend rises and carries the fumes with it, so they collect at the top. Used this way, it recirculates and cleans the air inside the enclosure. You can also duct it through the enclosure wall for single-pass exhaust.

Bill of materials

• Blower fan 120 × 120 × 32 mm, 12 V or 24 V: AliExpress, or this Amazon kit that comes with a wall adapter and a speed control dial.

• Speed control: recommended, to keep the airflow gentle. The Amazon kit includes it. With a bare fan, use a PWM speed controller and a power supply that matches the fan voltage.

• Filter media up to 28 mm thick

• M4 screws and nuts for the fan

• M3 screws and nuts for the rails

Print settings

• Material: PETG (I used Polymaker PolyMax PETG). ASA or ABS are better if your enclosure runs warm.

• Nozzle: 0.4 mm

• Layer height: 0.2 mm

• Walls: 3–4 perimeters

• Infill: 20–30%

• Supports: only for the fan case. All other parts print without supports.

Assembly note

The rails are directional. Check their orientation in the photos before you assemble.

About this description: I design, print and test everything myself. I'm a hands-on maker, not a writer, so I use AI (Claude, by Anthropic) to help me organize and polish the text.