Delta Fan Duct for Prusa Mini MK3S Bear: Sherpa Mini + Revo Voron
You should print the fan duct in a temperature resistant filament such as ASA/ABS, etc.
PETG might also work.
Update: Added v1.1 which should remove airflow restrictions from v1 - although I don't see any difference in overhangs.
The author remixed this model.