I needed to practice with Autodesk Inventor, so I designed this. It uses a 90mm (120mm diagonal from screw hole to screw hole) (25mm thick) fan. I used a 11.5 x 19mm switch. For the power connector, I just cut the barrel jack off a cord I didn't need. The filter is a 10mm thick carbon filter.
In this model I have added some features to the front to hold the bottom of the filter in place. They should print okay, but I have tested it. For the first one I did, I just used hot glue. I had issues with the fan screw holes lining up, and had to drill them out some. I believe I have now fixed that in this model.
Toner Plastics PLA