Just been admiring a friend's new kitchen. He commented the extractor wasn't
very good and I suggested he gives some thought to how air is allowed to
enter the kitchen to replace the air that is being taken out.

We got to thinking about why the fan is in the hood - and why isn't it on
the outside at the end of the duct (he has quite a long duct - crossing the
kitchen above the ceiling to get to the outside wall). I guess it makes
things easy from a selling point of view to have everything in one unit -
but we could see advantages in moving the source of noise to the outside.

Any thoughts or experiences of an external extractor fan?