Clive Arthur wrote:

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

The choice is louvred, gravity or cowled.

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

https://www.amazon.co.uk/12-White-Ai.../dp/B00PJ8FNBY

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

Chris
--
Chris J Dixon Nottingham UK


Plant amazing Acers.