Show HN: I built an under-the-door fan duct to lower bedroom CO2

This is my attempt to fix groggy mornings by lowering my bedroom CO2 from 1700 ppm to ~900 ppm.

I designed a simple, 3D-printed fan duct that directs air under the door to improve air circulation.

A note on the design process: I used CadQuery, a Python library for creating parametric 3D models. I didn't know tools like this existed and highly recommend it if you can program; it turned out to be more convenient than manually iterating on prototypes in a GUI.

The project is open source and the post explains the full build. Happy to answer any questions.