I had an animal die in a wall cavity and the stink is incredible. Reading around the best solution to minimize odor inside the house is to pressurize the rooms you can smell it in to push the smell back the way it is coming in rather than trying to suck the smell out. I had some MDF lying around, some ducting and an inline fan - just need to print this flange to tie it altogether. The sleeve is what I'd call just long enough if you have a circular clamp, but if you want to duct tape it on, extend the sleeve to about 10cm.
duct_flange_150mm_v1.stl | 204.6KB |