Quiet 60mm fan guard / grill

thingiverse

UPDATE: I learned that proximity to the spinning fan blade is a major noise contributor. I have included a second STL file that provides standoffs for the fan grill . My goal was to design a fan grill that would add very little noise to a very quiet Noctua fan. The blades in the grill are aerodynamically shaped (upside down teardrop) and there are no sharp edges to minimize the additional noise created as the air passes through the grill. I am sure that more could be done to make it even quieter, but this was my 4th iteration, so I decided to stop there. Fewer spokes would be quieter; the tradeoff I made was for safety at minimal noise. If you are curious, you can see the designs (and make a copy of them and modify them, if you wish) at https://cad.onshape.com/documents/eef193552316c8be0ffcc015/w/36eaa62a8dbfc72f319a7366/e/7c10a82f55967dd5787f3588 . Please let me know, in the comment section, of any improvements you make!