What tube vent size for wall bathroom extractor?

[JP_]

Have uncovered the old wall air vent and will be putting a wall mounted extractor here for bathroom.

What size tube /vent should i put in there? Want to put in now and insulate it in before plastering.

 

[foxhole]

Would need to know which wall fan you are buying , minimum is 100mm.But you could just insulate then cut through it when installing fan.

 

[JP_]

Probably something like
OOPPEN 4 Inch Pull Cord Extractor Fan Low Noise Standard Kitchen/Bathroom Extractor Exhaust Fan(ø100mm) https://www.amazon.co.uk/dp/B07RTXK1CR/ref=cm_sw_r_cp_apa_i_x8DUDbHX9V6AS

Needs a pull cord, rather than connected to light.

 

[JP_]

Just found this, comes with the venutt for wall. Does it look ok? Sounds good!

Xpelair DX100PS 4 inch (100mm) Simply Silent DX100 Bathroom Fan with Wall Kit-Pullcord Square, Cool White https://www.amazon.co.uk/dp/B00V4IMYV0/ref=cm_sw_r_cp_apa_i_uaEUDbVZJYAK3

 

[foxhole]

Ok, but low performance.Personally I would put vent over the existing and install fan to ceiling assuming it can be vented outside

 

[JP_]

New bathroom, was a box room, so no existing.

 

[foxhole]

New bathroom, was a box room, so no existing.

The vent exists?

 

[JP_]

No, just the old air brick hole.

What do I need to look for in a high performance fan?

Maybe something like this - I like the shutters

https://www.amazon.co.uk/Envirovent...tractor+fan+cord&qid=1572515715&s=diy&sr=1-10