New ensuite vent options

[Niscars]

I live on the 5th floor of a block of flats and want to fit an ensuite to the main bedroom. I do have an outside wall but drilling to the outside will be really difficult because of the height and getting permission from the block management / scaffolding etc.
The bathroom in the flat below (which I have access to) has an extractor fan right under where I want to put the ensuite. I can see the galvanised vent trunking in the void below my floor (see pics).

IMG_3505

• Niscars
• 19 Nov 2020

Fan in the flat below.

IMG_3506

• Niscars
• 19 Nov 2020

Trunking visible from above.

Can anyone please comment on the feasibility of installing a wall mounted extractor upstairs and then run trunking down behind the stud work to join into the existing trunking under the floor between the downstairs fan and the outside wall (about 30cm beyond the fan)?

The fan has a non return flap but I want to make sure I don't put my ensuite water vapour into the downstairs bathroom.

 

[polesapart]

Drill and fit your fan from inside

e.g. www.screwfix.com/p/manrose-internal-fit-wall-kit-117mm/9514x

 

[HERTS P&D]

Good shout PP.

Andy

 

[Niscars]

Many thanks, that does look like a good bit of kit.
Looking on the negative side of this though, I will still need block management permission for the hole.
Could anyone comment on feasibility of the original proposal to join into the existing please?

 

[Hugh Jaleak]

I would be very wary of trying to connect into the downstairs ducting, always going to be a risk of condensation, which could result in water dripping from the downstairs fan when your fan is in use. Fit an independent setup for your flat and avoid any conflict.

 

[Niscars]

OK think you're right, thanks.