Yes it’s 27 minutes, but the bits with coloured smoke are the best explanation of volume vs velocity that I’ve seen.
There are two things worth adding -
- having the dust collection outlet in the same room won’t save you from the micro dust that is the harmful stuff - all the rest is just inconvenience(!) therefore it’s best to duct from outside or at least from an enclosed cabinet that exhausts to the outside. This puts paid to the “flex and move the machine around is OK” argument.
- A fan capable of significant air movement exhausting to outside will also assist. “Significant” varies but somewhere between 10 and 20 changes per hour would be a nice starting point!
