A Backdraft Shutter is used with inline fans and duct, to stop air flowing in the “back” direction. It has “butterfly” wings and a very weak spring to minimise airflow reduction. The shutters are opened with the pressure generated by air stream and are closed by the spring.
The shutter housing is made of galvanized steel and the shutters are made of aluminium sheet.
Made of metal and various sizes available.
Bill –
Excellent product. Works perfectly.