Duct Flange - Fits 120mm PC Fan Profile and 4 inch AC Duct

Flange that can be mounted onto a 120mm PC fan and then interface with a 4in" AC duct in order to vent heat and fumes outside.

I am using thinkingalaud's original model  for the flange that faces outside, but needed to remix their model to properly interface with the 120mm fan I am using to create a negative pressure vaccuum in my printer enclosure. Otherwise, a good portion of the fan was blocked and air was escaping through the sides instead of into the AC duct.

Supports are needed only for the internal portion that interfaces the fan directly.

The fan I am using is a Noctua heavy duty fan, which creates enough static pressure to pull fumes through charcoal and HEPA filters.