Multiple-zone VAV systems with direct digital control of individual zone boxes reporting to a central control panel shall have automatic controls configured to reduce outdoor air intake flow below design rates in response to changes in system ventilation efficiency (Ev) as defined by the Florida Building Code, Mechanical.
Exceptions:
- VAV systems with zonal transfer fans that recirculate air from other zones without directly mixing it with outdoor air, dual-duct dual-fan VAV systems, and VAV systems with fan-powered terminal units.
- Systems having exhaust air energy recovery complying with Section C403.2.7.
- Systems where total design exhaust airflow is more than 70 percent of total design outdoor air intake flow requirements.