Seems I've been over thinking this though. I wasn't looking at the fans as a branch and that was sending me in circles. Gonna bump up the plenum size just a bit to compensate for the rectangular duct losses and to keep the velocity and pressure down at the bottom.
Yea the inlet conditions are...
Yea the circle cutouts you see are fan locations and they are pulling from the plenum and blowing into the machine(away from you-into the page). What you can't see is that on the inside there a stack of products that are being stored and allowed to cure after a coating process. The fans are...
I've attached a screenshot of what I've detailing out for a project I'm working on. In short its just a plenum to allow the fans along the back to recirculate and keep airflow over product that's being cured in a buffer inside.
Fans are 4" axial fans @ 100cfm with .325" H20 max Pressure.
2...
