I plan to insert an in-line fan (e.g. Manrose MF125T) in the ducting:- https://www.flickr.com/x/t/0098009/photos/13629865@N03/33815362086/
The installation instructions state:- "INSTALLATION INSTRUCTIONS FOR MF FAN MODELS
This type of extractor fan is designed to work inserted into any stretch of air extraction conduit, whether positioned vertically or horizontally.
The easiest way to add the fan is by fixing it to the woodwork which is at an angle. Would this cause any extra noise or bearing wear?