What feature must each volume damper used in air supply adjustment have?

Each volume damper used in air supply adjustment must have access. This is crucial because the ability to access the damper allows for proper adjustment and maintenance, ensuring the airflow can be balanced according to the requirements of the system. If a damper is not accessible, it can lead to difficulties in achieving optimal performance, making it hard to troubleshoot or adjust the airflow as conditions change or as the demands of the HVAC system evolve.

Access is essential for technicians to reach the damper easily, whether for adjustments, inspections, or repairs. This feature helps ensure that facilities maintain efficient airflow across different areas, improving overall system performance and comfort.

While sealing, covering, and locking may be important for other components, those features do not directly address the necessity for adjustment and maintenance like access does. The focus on ensuring that systems stay balanced and functional emphasizes why access is the most critical feature for volume dampers.