Backdraft Dampers

Backdraft Dampers for One-Way Laboratory Exhaust Flow A backdraft damper is a passive duct component that opens when airflow in the intended direction creates sufficient differential pressure and closes when flow stops or reverses. The PP/PVC backdraft damper is intended for compatible laboratory exhaust ductwork where reverse airflow needs to be reduced without an electric actuator.

Select It from the Installed Pressure Conditions Provide the duct size and orientation, normal and maximum airflow, available opening pressure, expected reverse pressure, air-stream chemistry, temperature, material, connection, mounting direction, and accessibility. Blade weight, friction, installation angle, duct velocity, and system pressure influence opening and closing behavior. Confirm that the fan and duct design can overcome the damper resistance under the required operating condition.

Define What the Damper Must and Must Not Do A backdraft damper helps prevent unwanted reverse flow; it is not automatically a bubble-tight isolation valve, shutoff valve, pressure regulator, fire damper, or smoke damper. It also does not provide active airflow modulation. Use Motorized Air Dampers when a controller must command the blade, and use manual balancing dampers when a fixed adjustable restriction is required.

Installation should preserve the specified flow direction, free blade movement, service access, and suitable support for the duct component. Submit the duct layout, fan duty, airflow and pressure values, mounting orientation, chemical list, temperature, connection details, quantity, and destination so the backdraft configuration can be reviewed against the actual exhaust system.