I agree with ChasBean1
A steel mill environment isn't going to be the cleanest and if you are exhausting 13600 cfm and supplying 14600 cfm i would question the quality of the air being introduced not the pressurization of the room.
what level of filtration is being used? maybe an approach...
What is the reason for the 100% outside air? If it is due to the processes within the building, there might be a need for the dampers to adjust/regulate the airflow provided.
localized Building/space over pressurizing where medium to high efficiency filters are changed out is a concern if...
One thing to consider is the supply air temperature delivered to the duct system. If the temperature setpoint is governed by a room (in this case the shelf area)which does not need air as cold or hot as the room(s) with the thermafuser you may experience some problems.
an occupied office with...