The Verasys system uses a low pressure duct design. To reduce noise problems, duct pressures must not exceed 1 in. W.C.
Avoid undersizing primary trunk ducts, especially for pressure-dependent systems. Pressure-dependent systems are zone damper assemblies without the airflow sensor. You can maintain relatively constant pressure to each zone when you have larger truck ducts. Keep duct runs as short as possible, and the trunk duct system as symmetrical as possible to facilitate system balancing. Wherever possible, run the trunk ducts above corridors and locate the zone dampers above corridors to reduce noise and facilitate unit service. Size trunk ducts no more than 0.1 in. W.C. drop per 100 feet, and a maximum duct velocity of 2,000 feet per minute (FPM).