Kitchen Extractor Vents

[Spinny]

Any suggestions on the best type of external kitchen extractor vent to install for an integrated through the wall 150mm extractor ?

Needs to be installed on a cavity block wall which will have external cladding and is south facing.

 

Should I have a backdraft shutter or will this just compromise the extractor performance ?

Will the cladding get stained over time by the outflow ?

Will water condense and create water marks/drip marks on the cladding ?

 

Thinking about this...Bullnose vent ?

[Redbeard]

4 hours ago, Spinny said:

Thinking about this...Bullnose vent ?

I have one of these. Pretty enough but there's no back-draught prevention.

[Spinny]

48 minutes ago, Redbeard said:

I have one of these. Pretty enough but there's no back-draught prevention.

I guess the only back draft protection I am aware of are the backdraft flaps that open one way only. However these seem like they would obstruct the outward flow from the extractor even when open. Probably not an issue for low volume bathroom/utility extractors, but presumably not so desirable when trying to rapidly suck out cooking steam and smells ?

I have never had a proper extractor before so am a bit clueless.

[Redbeard]

Well... the louvred covers with loose flaps gives some back-draught protection but if the wind is in the wrong direction they flap and chatter like nobody's business.  I swapped them for cowls with a 100mm flap which, being 'sheltered from the wind', does not 'chatter'.