extractor hood and capped chinney

[wildm]

I have a extarctor hood that currently vents into a chimney. There is no other use for this chimney.

I am having a loft conversion and need to do something with the chimney for the dormer. If this chimney was lowered and capped with air bricks added is this sufficient for the extractor hood. Is there a minimum requirement here?
What other chimney options do I have?

Thanks

 

[noseall]

If this chimney was lowered and capped with air bricks added is this sufficient for the extractor hood.

And where ultimately will all the extracted moist air end up?

What other chimney options do I have?

Vent the extractor to the nearest outside wall.