Refrigeration Plant Operator B Practice Test

Which of the following is NOT a function of modulating dampers?

1. To throttle the balance of total airflow

2. To control humidity levels

3. To modulate air volume through cooling coils

4. To regulate the mixture of air flows

The correct answer is: To control humidity levels

The function of modulating dampers primarily involves controlling the flow of air within HVAC systems. They are designed to adjust airflow based on various operational requirements, making them essential for maintaining system efficiency and optimizing performance. One key aspect of their operation is to throttle the balance of total airflow, ensuring that the desired amount of air reaches different parts of the system. Additionally, these dampers play a crucial role in modulating air volume through cooling coils, maintaining the appropriate temperature and improving energy efficiency. Another function involves regulating the mixture of air flows, particularly when different types of air—such as return air and fresh air—need to be blended to achieve specific air quality and temperature goals. Humidity control, however, is not a direct function of modulating dampers. While airflow impacts humidity levels indirectly, the actual regulation of humidity typically requires specialized systems such as humidifiers or dehumidifiers, rather than relying solely on dampers. Therefore, the correct answer highlights that modulating dampers do not serve the primary function of directly controlling humidity levels.