I designed a silencer for the noisy case/exhaust fan and auxiliary fan on the Centauri Carbon. The silencer redirects the air flow, allowing the sound to be absorbed and dampened as it travels along the long, winding path. 

With the lid and door closed, it achieves noise cancellation of ~4 dB without overloading the fans. 

I printed this out of PETG, mostly without supports, aligning the bridge infill direction perpendicular to the ribs to minimize the bridging distance. You only need support for the external inlet/outlet edge, not in the circular openings. 

You will need three M3 screws to attach it to the printer; you can use the ones that came with the printer. 

Please leave a like or review if you find my work useful, your support is much appreciated!