They may be installed while in the HVAC ductwork and therefore are induced to close after they perception smoke. Smoke dampers usually are fabricated from aluminum and have a motorized actuator that closes the damper. Backdraft dampers are either gravity or motorized. Gravity backdraft dampers make use of the force https://marcovnbre.blog-a-story.com/17799776/an-unbiased-view-of-air-control-dampers-for-hot-climates