While planning ducting for dust control within the Dusty Area, the matter of fume extraction from the Laser Cutter (when it is moved to the space between the Dusty Area and the Metalwork Area) is also relevant.
The obvious route is from the laser, through the Dusty Area, to an opening in the end window over the street.
This would be achieved using 8" flexi hose (we have), and moving the window sash board with a hole to the end position, replacing the glazed one to the position behind the current location of the Laser Cutter.
Looking into prices for a better, long-term solution, it appears that rigid steel spiral ducting is rather cheap, almost (not quite) as cheap as the plastic flexi-stuff (not actually approved for commercial use).
It is suddenly apparent that the better way might be to run a rigid duct from the Laser Cutter, over the Metalwork area (to extract welding fumes as well, and then directly out of a hold in the upper pane of the windoe by the back door. This, with a cowl, would be less obtrusive, a more direct run (no need for flexi-duct), and solves two problems at once.
Looking to this option, I am going to buy a single 3m length of 8" ducting which will form the link from a fan over the new Laser Cutter location to the rear window in the Dusty area. The flexi-duct that we have can then form a temporary link to a hole in the window panel.
Expected expenditure: £25