120 mm turbo fan stator greatly increases air pressure diverting the thrown back/sides air to proper direction.
It does NOT have moving/rotating part - fins are static, just air deflectors!
It can be added before or after fan, or on both sides.
Many uses. Say, you can add it to computer CPU fan to improve cooling
I used it with my custom house heat exchanger.
Note: With added airflow it adds air noise
You can use it with reduced fan speed to achieve same airflow and lower power consumption.
New version with flat bottom added - 120_mm_Turbo_FanStator-_flat_bottom.stl
It does not require supports.
Other stl file requires support. I did not remove it because It has slightly more proper shape it terms of air dynamics. It is still negligible difference, probably
2 top/bottom layers and shell thickness are enough