IRIS type round regulating damper, manually operated. The IRIS regulating damper has the following characteristics: low noise, central airflow, nozzles for air flow measurement. Full opening of the damper allows easy cleaning of the ventilation system.
Thanks to the way the blades are adjoined, the damper allows accurate determination of air flow. The differential pressure measured at the two nozzles can be used to determine the air flow, using the formula indicated on the damper plate.