Extractor grille - what type?

[Clive Arthur]

I need a grille on an exterior wall for a 150mm cooker hood extractor.

The choice is louvred, gravity or cowled.

Which is best?

Cheers

[Huge]

IME, gravity. Otherwise you get a howling gale back through the hood when it's switched off.

[Clive Arthur]

'IME' is just want I wanted to hear, thank you. Grille ordered, case closed.

Cheers

[The Natural Philosopher]

Beware that gravity ones will clack and flap in a howling gale....

[Huge]

You're most welcome.

[Harry Bloomfield]

Huge brought next idea :

I have had a gravity type installed for some 20 years and still working well. It uses an above centre pivot point, so if the wind blows on it, it tends to close even tighter.

[Tim Lamb]

Hmm.. they also clatter on gusty days:-(

[JoeJoe]

Best one I installed was a fan that has a grill that opened when the fan was turned on, and closed when turned off.

Wasn't particularly expensive, but required fitting directly to the wall

- i.e. no ducting.

[Huge]

I'm afraid they do, yes. I used to have a superb Ventaxia extractor fan with solenoid operated louvres, but I've never seen anything similar for cooker hoods.

[Chris J Dixon]

I had a draught problem with my ducted kitchen extractor fan, which faces west, and fitted a cowl BM424W:

It seems, subjectively, to reduce the effects when high winds are blowing against it.

Chris

[Brian Gaff]

Also somewhere an insect trap grille might be an idea. Wasps can get in and nest. Brian

[PeterC]

I fitted one over the backdraught shutter on an extractor. The outlet is in the SW wall, so I did it mainly to keep out the weather. There's still some clattering, but a kitchen extractor probably has heavier louvres and is lower down. For fewer beer tokens:

Brown or white.

[Max Demian]

I had an extractor with a chunk of glass wool or similar behind the inside grill, which collected dust so I removed it. Most of the (gravity) louvres on the outside grill had fallen off. I expect it was to stop insects, but there was a 15' duct so I don't suppose many would have been so adventurous. Wasps might have made a nest /inside/ the duct I suppose.