They are really set up in the HVAC ductwork and therefore are activated to shut after they perception smoke. Smoke dampers are often product of aluminum and have a motorized actuator that closes the damper. THIS column provides specifics of the use of out of doors air dampers in hot https://air-control-dampers-for-h34456.blogdiloz.com/35472840/detailed-notes-on-air-control-dampers-for-hot-climates