ᐅ Complete ventilation duct for upper floor through timber stud wall?

Hello everyone,

We have discussed an initial proposal for the routing of ventilation ducts for our central mechanical ventilation system with the requested plumbing company.
The ventilation unit will be located in the utility room, and the air distributors are planned to be suspended from the ceiling between two wooden beams. To supply the attic and the loft, the ventilation ducts are to be routed through the timber stud wall between the bathroom and the bedroom into the loft and then distributed to the respective rooms.

We are now wondering if a total of nine DN75 (3 inches) pipes (3 exhaust, 6 supply) can be installed without issue in a timber stud wall (studs 10cm wide (4 inches) with 8cm (3 inches) wood fiber insulation), clad with OSB and drywall on both sides. Our concern is that the wall might become very sound-transmitting without sufficient insulation, compromising the necessary soundproofing between the bathroom and the bedroom.

Does anyone have experience with this type of duct routing?

You could use flat ducts and have them insulated.

Hey, are you referring to having enough insulation on both sides within the wall?

We asked the same question, but we were advised against it because cleaning the oval ducts is reportedly more difficult.

This way, you will definitely have enough insulation in between to avoid sound bridges.

Of course, a thicker wall would also be an option.

How often do you plan to clean the ducts?