The Anycubic AirPure filters are cheap and quiet and have rechargeable batteries so you can move them between printers easily. However, the replacement activated carbon blocks are small and expensive (and not available in my country!) so I've made this to be able to use my carbon pellets. My first few iterations, which were conceptually based on the Bento Box, looked like little pizza ovens, so I went all the way pizza.

Features

• Prints as a single piece, no need for magnets and such.
• Pattern on bottom face makes the first layer go down cleanly.
• Grates inside the oven capture some of the carbon dust (hopefully).
• Fits in Bambu X1C/P1P rear right corner, as well as in many other printer enclosures.
• It's just cute.

Print settings

• Import both STLs together so that they're aligned to each other.
• Add supports, but block supports by painting support blockers on the “mesh" part (see pictures) make sure to check preview of mesh
• Modify the “mesh” part to have no walls, no top and no bottom, with an appropriate infill - such as 50% triangle or 40% grid. Don't use infill that can't be printed in mid-air such as honeycomb.
• Adjust the remaining settings as you see fit.
• Tested with PLA+, ABS+ and PETG-CF. The ABS+ version came out a little bit snug but still easy to fit (reduces chances of pellet spillage), the PLA+ and PETG+CF versions were perfect fit - consider doing a test print of just the top section that fits into the filter. Scale to your printer and material's needs. Using PLA is generally not advisable in an enclosure but probably good enough for light enclosures. PETG supports are a little difficult to remove. ABS is recommended.
• Check your preview again before printing!

Make sure your activated carbon isn't acid washed as that may damage your printer! I've opted to pay the premium for the Nevermore stuff myself for the peace of mind. See here for more information: https://github.com/nevermore3d/Nevermore_Micro#sourcing-the-proper-acid-free-carbon

The stock AirPure module blows air upwards, so, downwards when upside down. If you want air to blow upwards like a real chimney, you can open it up and flip the fan. Delete the internal grille while you're at it to reduce head loss.

These are potentially compatible with the Elegoo filters but I don't have any to test. Could work with some minor scaling if it's a different size, if you find that scaling is needed, please share with us.