Shower Drain Silencer

We have been annoyed for quite some time by the absurd amount of noise emanating from our shower drain. The noise is enough to wake a person, even with the bathroom door closed. The noise is magnified by the tile floors and walls of the bathroom. The noise is similar to that of dropping coins into an empty coffee can, and can be heard throughout the downstairs of our home, even with the bathroom and bedroom doors closed!

When I investigated, I discovered the vertical drop from the shower floor to the P-trap water level is about 18 inches. I also found that there are two drain height extensions, indicating that the shower has been remodeled more than once. I trimmed away a bit of excess glue and gasket material from the joints, which helped reduce the noise a little by encouraging the draining water to run down the walls of the pipe. The noise was still very loud, so I decided to do something more about it.

The result of my tinkering in SolidWorks is the Drain Silencer. My goal was to direct the water to cling to the pipe walls (using what little surface tension there is in soapy water), and to eliminate any straight path for sound waves to escape the drain.

I printed the model on my new MK4 using a 0.6mm nozzle and Prusament PETG. I set the top AND bottom solid layers to zero, and used spiral vase with a 0.75mm external perimeter extrusion width. I also used a 2mm outer brim with a gap of 0.05mm to anchor the print to the sheet. I trimmed away the brim with scissors. The part is oriented on the print bed as it is when inserted in the drain.

The slight flare at the top is to provide a seal with the top of the drain. The rounded flare at the bottom is intended to direct water toward the pipe walls. I have no idea if this is effective.

The resulting part is a snug fit in the shower drain, and the noise is almost completely eliminated! The drain noise is now lower than the sound of the water from the shower head. Problem solved!