Lack stack printer enclosure exhaust

This was designed to be a quiet exhaust for a typical Lack Stack type enclosure, using a high static pressure 120mm fan (e.g. Noctua NF-P12) with carbon filtration to cut down on plastic odors. 

I had originally planned to use a 4" (100mm) canister filter, but found that to be annoyingly heavy and large to have sitting on my enclosure, so made a different adapter that accepts activated carbon sheet filter (readily available from Amazon, etc.). The canister filter did a somewhat better job of odor elimination, but the sheet filter does quite well with two 1/8" layers for me. In either case, the reduction in odor is substantial and well worth adding the exhaust, in my opinion.

I've included a template ring for you to build any other exhaust adapters, should you wish to adapt this to standard HVAC components, etc.

A velocity stack on the intake side improves airflow as well as the sound, and is optional but recommended.

Upper/lower in these descriptions assumes you will mount this exhaust on the top of your enclosure. You will need to cut a rather large hole (use your printed parts to mark the hole) in your Lack table; for me, drilling corner holes and using a fine-toothed wood blade in a handheld jigsaw worked well to cut through the whole table top at once, but you could use a utility knife to cut the top/bottom holes easily enough. These parts have a substantial flange to hide any messy cuts.

This could be easily adapted for use in enclosure temperature management, and you may see such parts show up here in time.

OpenSCAD source is included, feel free to remix with attribution (and I'd love to see what you do with it). 

• ExhaustBase: Upper half of the main unit, this screws into the top of the table and accepts filter adapters.
• FanAdapter-120mm: Lower half of the main unit, this screws into the bottom of the table. Printing with support is recommended for this piece.
• IntakeVelocityStack-120mm: Velocity stack that should screw onto your standard 120mm fan; has a cord passage that fits a Noctua NF-P12 and probably most others.
• FilterAdapter-4x1Sheet-Holder: Holds 4"x4" (102x102mm) sections of carbon sheet filter, up to 1" (26mm) thick
  FilterAdapter-4x1Sheet-Cover: Simple perforated cover for above.
• FilterAdapter-100mm: A round 97mm O.D. to fit _inside_ the 4" carbon filter I sourced (G Hydro brand).
• ExhaustAdapter-Template: Base ring you can design from for a custom filter/exhaust adapter.