What is Smoke exhaust ductwork?

Smoke exhaust ductwork, in Europe, is typically protected via passive fire protection means, subject to fire testing and listing and approval use and compliance. It is used to remove smoke from buildings, ships or offshore structures to enable emergency evacuation as well as improved firefighting. In North America, fireproofed ductwork may be used for the purpose of smoke exhaust, but it is more common to use unfireproofed return air ductwork, whereby no fire testing or listings are employed to qualify the ductwork for this use.