I need to install a 80mm fan to an good looking and high wife acceptance factor 3D printer enclosure. Because acoustic was a problem, i chose to use thick walls with the fan built in.
Instead of make a precise and exhaustive woodwork to built in the fan, i choose to design this housing. It's like an adaptator to fit a square 80 mm fan and the compatible square fan grid/filter in a circular hole made with a hole saw.
I print mine with wood filled PLA.