Duct static pressure control is a method of controlling the airflow in an HVAC system by regulating the static pressure in the ductwork. This is typically achieved through the use of sensors, actuators, and control algorithms. The sensors measure the static pressure in the ductwork, and the actuators adjust the fan speed or damper position to maintain a setpoint pressure. This helps to ensure that the airflow is evenly distributed throughout the system and that the desired indoor air quality is maintained.