Powerless ventilation fans for window ?

[MoonMan2]

Looking for a simple form of ventilation that does not involve a power supply. Seen them in pub toilet windows, some with a pull cord that are used to open and close the vent to outside air.

Basically they have a free moving rotor that rotates with wind (not electrical) and provides a very simple form of ventilation. Would be looking for one that is about 130mm in diameter.

Does anyone know what these rotor vents are actually called and where I can buy them, I have tried looking.

thanks

 

[JohnD]

it's just a hole. The plastic rotating part is driven by the air passing naturally through it, it's not a fan and serves no purpose except to entertain the homeowner.

Rather than make a hole in a piece of glass, IMO it is better to hire a core drill and make a 110mm hole through the wall, put a plastic duct liner in it, put a cowelled vent on the outside to prevent rain penetration or backdraught, and a simple grill on the inside. When, later, you realise you need a proper fan, it will fit easily to the duct.

 

[crank39]

If its for a wall then google 'passive dehumidifier'

 

[foxhole]

http://www.ncdoubleglazing.co.uk/ep...es112297_es121310152893/Categories/glassvents
Had one years ago in bathroom a stiff breeze would rip it out and have to be replaced.

 

[^woody^]

The rotor is actually intended to slow down the passage of air, and to prevent draughts and noise

Google for " Vent-a-matic " as they are very common

 

[big-all]

if its a bathroom/kitchen/shower room you need a powered fan to extract the moist damp air otherwise it will be blown into the house
the running costs will be no more a few pence a week assuming about 10 hours a week operation