What do I need to allow air intake into a bathroom?

[Lusi83]

I want to put a ventilation duct through an internal plasterboard wall (with cavity) in the bathroom to allow air intake/encourage flow through...

Started looking for what I (thought) needed and have managed to confuse myself...didn't realise there was so much choice...

It would be nice to be able to close the vent in the bathroom whilst in the bath if it is draughty...but need to leave it permanently open on the intake side (it will be out of easy reach)....

And some ducting to go through the wall and I guess everything has to line up ... do I fix the grills to the wall or to the duct?

Thinking either white or aluminium will be the most discreet - (pale green/blue walls on both sides and white ceilings and paint work) or maybe even paintable (if such a thing exists)?

Also am I right thinking the ones that are suitable for gas aren't for me because they can't be closed?

Any advice on what I should get?

Thanks

Sorry a quick edit - on a slightly different topic but still ducting just thought if you know about stuff like the above you will definitely know the answer to this ...flexible ducting (through cavity wall to outside)
Should it be stretched out and trimmed to length or squashed up?

 

[big-all]

basic answer you need to ventilate to the outside world via wall ceiling floor with a tube solid /pipe that will only vent to the outside world

 

[Lusi83]

Sorry I didn't make that very clear - there is a fan to the outside world in there (the squashed up flexible duct one) but it is next to the window/door at the opp side of the room from the bath...

I am looking to allow (warm) air from the landing into the bathroom to encourage flow through to the fan to the outside world...

 

[Richard C]

Normal method of encouraging through circulation without having the window open is to cut a 1/2 inch off the bottom of the door; no air in = no air out!

 

[foxhole]

I use small white circular 2inch vents thru plaster board , no need for internal ducting as the air is drawn from the house thru to shower room, mine happen to pass thru boxing containing LV lighting so also cool the lights while only allowing warm air into room.Placed at high level are unobtrusive.

 

[Lusi83]

Thanks...

Normal method of encouraging through circulation without having the window open is to cut a 1/2 inch off the bottom of the door; no air in = no air out!

Problem with this is the fan is near the door...so won't encourage the air to flow through and also next to the window...

I use small white circular 2inch vents thru plaster board

Do you have a link to these vents? They sound quite interesting - I will need some kind of ducting but that small I could probably make something (thinking could even use something like 40mm waste pipe... )

 

[foxhole]

http://www.sdslondon.co.uk/white-plastic-vents/soffit-vent-50-mm.html

 

[Lusi83]

Thank You - they look like they might be perfect ...I didn't know ones that small existed - I might add a couple to the top of the shower enclosure as well!