Office and warehouse in both Crystal River & New Port Richey ,FL
Rooms all need a ducted return or a return path to the equipment.
Return path can be under the door(often not large enough),transfer or jumper duct from the room to the area the ducted return is placed.
Air can't be supplied properly to a room,unless it can be returned from that room. Try blowing into a paper bag,that has no holes.
Failure to provide proper returns,will place positive pressure on rooms,causing exfiltration of conditioned air,at the same time the area where the return is,will be negative pressure, causing infiltration of unconditioned air,up goes the utility bill,down goes comfort and indoor air quality.