Moving from the top, the blue duct spreads air across the ceiling of the fabrication level. This filtered air flows downward over the equipment and out through the floor grates.
Below the fab level, supporting equipment is located (e.g. vacuum pumps) along with the fluid and gas plumbing.
On the floor of this support level, air is collected and sent to blowers where it is combined with fresh air (green duct). This air is then pushed up the vertical duct (at the right) back to the attic level, completing the cycle.
