National Environmental Balancing Bureau (NEBB) Certified Professional (CP) Practice Exam

Balancing systems that include an economizer requires coordination between outside air control and the control logic so that airflow is accurate in every operating state. The outside air damper and the economizer logic change airflow as outdoor conditions and indoor conditions change, so you must verify that the outside air intake is correctly controlled, that the economizer responds to space conditions smoothly, and that the measured balances are valid across all modes (economizer enabled, disabled, and transitional states). That’s why the best approach is to check and verify the outside air control, observe how the economizer logic transitions with indoor conditions, and confirm that the balance remains correct as the system switches between modes. This ensures the design intent is met in real operation and that readings reflect true performance in every state. Disabling the economizer during balancing would remove the very variable you need to assess and could mask control or damper-calibration issues, giving a false sense of correctness. Measuring only supply air temperature ignores airflow quantities and damper positions, so it can’t confirm proper balancing or ventilation rates. Opening all dampers to maximize outdoor air during testing distorts normal operation and can lead to unsafe or non-representative results, preventing an accurate assessment of the system’s performance across its intended modes.