Long Description:
The HVAC system is sophisticated with automation designed and installed to provide adequate exhaust flow for waste air elimination. The system is malfunctioning as inspection reveals strong odors on all floors and an overall negative internal building pressure. A pressure imbalance of this nature is an indicator that exhaust air volume is exceeding supply air volume. The design specifications call for positive envelope pressure as the OSA volume is specified to be greater than the exhaust volume by approximately 5%.
The laboratories and offices through out the building are separate zones, each with their own VAV supply air box and VAV exhaust air box. These zones have their own control system and are not connected to the AHU/Exhaust fan control system. The 100% outside VAV air handlers #1 and #3 are coupled via electronic controls to their respective exhaust fans in the penthouse. Through a control algorithm, AHU #2 OSA dampers are modulated to control the internal envelope pressure. Additionally, the inlet vanes within the exhaust fans are modulated to maintain a constant exhaust suction pressure. When operating properly, the AHU/Exhaust control system reacts to the requirements of the many zones it supplies.
The scope of this project is to rebalance the systems airflow and verify that the control system is operating within specification. Funds are included for repairs that may be found necessary.