Models are printed in PLA+ (eSun) at 200c. Duct doesn't seem affected by heat creep from nozzle proximity. Standard settings in Creality Print V5 seem to work well but feel free to play around.
Stock 4010 fan and fittings can be used to mount.
The author remixed this model.
The pieces have been modeled in Sketchup from scratch but are heavily influenced by the referenced models. I've just removed material to suit my aesthetic and provide hassle free print orientation.
I know nothing about duct design (besides the few videos I've watched), but the duct has been through a few iterations and tested and this one seems to perform the best. Air stream is directed to intersect the tip of the nozzle. Happy for feedback if you decide to use it.