2 inline extractor fans joined to single ducting

[portuguesejohn]

I recently moved into a new house which has 2 upstairs bathrooms: A family bathroom + ensuite. Each bathroom has a dedicated inline extractor fan in the loft, but I just realised that the one for the ensuite just extracts to the loft space (a classic! ) ... The main bathroom one appears to be fine as it extracts to the outside via the soffit.

Both bathrooms are directly next to each other, so both extractors are very close. It would be possible to run the ensuite one to the nearby outside wall, but access to the outside is complicated due to a pitched roof extension - it would definitely need scaffolding in order to fit a grill.

My idea to remedy this is to join both ducts together via a Y piece, with 2 non return backdraft shutters - with the intention of stopping one bathroom from extracting to the other one.

So, effectively:

https://www.screwfix.com/p/manrose-circular-y-piece-connector-white-100mm/23574?tc=SC6&gclsrc=aw.ds&gad_source=1&gad_campaignid=22599666687&gbraid=0AAAAAD8IdPymksmnzyqFRWWak6RjV6ghY&gclid=Cj0KCQiArOvIBhDLARIsAPwJXOawDo-KwoAYOfLSrEuOxESO2EiTTjc9L5HPpaEuJBMLufRZK_eJksgaAjnnEALw_wcB

https://www.tlc-direct.co.uk/Produc...045&gbraid=0AAAAAD-6GhlQ4Cxn0gQ5ftr_-17buer-r

Would this be a suitable solution?

 

[Wayners]

With centrifugal fans which you will need you will get pressure loss with poor or no extraction imo.

I've seen that tried before and it failed