Ventilation pipe on the outer wall Poroton T9

Hello,

I have my controlled residential ventilation planning, and the following:

Manufacturer/planner suggests interior walls supply air ducts (75 mm) on the upper floor with a wall thickness of only 10 cm??
My general contractor proposes to place the supply air ducts (flat channels 55 mm) in the exterior masonry (Poroton T9 36.5).

In my opinion, interior walls are out of the question, exterior walls... well, doesn’t that weaken the exterior wall (sound, insulation... etc)?

On the ground floor, I then get ceiling outlets, where I consider the ones in the living room corners (potential seating areas) still critical, but I see no alternatives here.

I would be very grateful for suggestions and ideas!

Thanks!

Hello,

Manufacturer/planner suggests interior walls for ventilation duct (75 mm) on the upper floor with a wall thickness of only 10 cm??

Excuse me? What do you mean? I suppose you're asking if it's possible to fit a 7.5 cm ventilation duct in an 11 cm wall.
Clear no, it's not possible!
According to my expert, no installations at all are allowed in 11 cm walls, except for electricity and sockets.

Regards,

Andreas

I and also my general contractor are surprised that this came as a proposal from a renowned manufacturer planner. How do you see it with the exterior walls as an alternative?