Exhaust issuses

[Bertho]

I have been reviewing the 900 x600 kit builds and I only see a general exhaust port at apparently random location. I have not noticed any comments about air intake. Since I am in the planning stages for a customize kit based unit that brings up the arrangement used on my Universal laser:
There is an air intake below the front door and the air then travels up the hollow door and exits in a long slot the full width of the cutting table, just above the table. In the back of the unit there is a similar exhaust slot, also the full width of the table. I forgot the blower rating but a very large one is required. The net result is a very strong air blast/ exhaust over the cutting area.

I have also built a vacuum hold-down/exhaust extraction table to use as required but all comments I have seen have been related to that. Has anyone set up a regular controlled airflow exhaust and how was it done?