bathroom extractor fan questions

[xyz321]

Hi, just couple of questions on backdraught shutter. My fan is a 4inch vent axia which just extracts out of side of bathroom wall in open (on a semi detached house). There is an air brick fitted on the outside but no ducting or backdraught shuttter. I am replacing this fan with new one as its on its last legs. New one will be same size as current one.

1. Do I need any ducting? The fan outlet has to go through the to thickness of wall only. If so will flexible ducting work.

2. Is there any good backdraught shutters with springs to Minimise noise due to wind when not in use?

3. Do the ducting and backdraught should there simply attach at back of fan or do I need to use any adapters or duct tape etc.

Ta

 

[jj4091]

Buy a fan with built in backdraft shutters. You won't need ducting if the cavity is sealed around the vent.

 

[xyz321]

Buy a fan with built in backdraft shutters. You won't need ducting if the cavity is sealed around the vent.

Thanks. I bought a fan (envirovent silent 100t) with said shutter but their definition of shutter is a thin, transparent plastic film..

 

[JohnW2]

Thanks. I bought a fan (envirovent silent 100t) with said shutter but their definition of shutter is a thin, transparent plastic film..

It might actually work and, if it did, it would be a lot quieter than the clattery (in the wind, when fan off) shutters.

You asked about sprung shutters to minimise that noise, but I rather doubt (but may be wrong!) that the average 4" fan would be able to open the shutters if they were held closed with springs strong enough to prevent clattering in the wind.

Kind Regards, John

 

[jj4091]

A cowl over the outside of the air brick would help prevent backdraughts.

 

[JohnD]

I find cowl vents pretty good. They have a single large gravity flap vent under the cover. The cover protects the flap from most wind. You can buy extractors with their own electrically or mechanically operated backdraught shutter, or a gravity flap duct.

colours and sizes vary

http://www.screwfix.com/p/manrose-cowl-vent-brown-125mm/72422

 

[Iggifer]

Or this, quite expensive in terms of fans, but also pretty decent. Backdraft shutter is second to none.

https://www.airflow.com/Product-Detail/pg_IC15/iCON-15-Fans/72683501/iCON-15-