These are set up inside the HVAC ductwork and are induced to close once they perception smoke. Smoke dampers are frequently manufactured from aluminum and possess a motorized actuator that closes the damper. Backdraft dampers are both gravity or motorized. Gravity backdraft dampers make use of the pressure of gravity https://air-control-dampers-for-h46778.blogripley.com/37512678/the-smart-trick-of-air-control-dampers-for-engine-sheds-that-no-one-is-discussing