$14 Fan Ventilator 3D model by ecati. Available on CGTrader with 25635 polys and 37687 vertices. Check it out on CGHub.
SKP (Sketchup, filesize: 1.83 MB), OBJ (OBJ, filesize: 1.59 MB), FBX (Autodesk FBX, filesize: 2.18 MB), 3DS (3D Studio, filesize: 907 KB), DAE (Collada, filesize: 928 KB)