What is the function of a zone control system?

• A. To filter air entering the system
• B. To regulate refrigerant charge
• C. To control temperature in different areas or zones of a building with separate dampers or thermostats
• D. To schedule maintenance tasks

Answer: (C)

Zone control systems manage temperature in different areas of a building by using dampers in the ductwork and separate thermostats for each zone. The idea is to keep each area at its own preferred temperature by modulating airflow: when a zone needs heat or cooling, the controller opens the appropriate dampers and signals the HVAC equipment to respond, while dampers for other zones close or reduce airflow. This targeted control saves energy and avoids overshooting temperatures in unoccupied or less-habitable spaces, improving comfort and efficiency.

Air filtration, refrigerant charge, and maintenance scheduling are separate functions. Filtration handles air quality at the air handler, refrigerant charge relates to the refrigerant in the cooling cycle, and maintenance tasks are service activities rather than how comfort is distributed throughout the building.