Fire dampers are not required at shaft penetrations if steel exhaust ducts extend vertically at least how many inches?

Fire dampers are an important component in HVAC systems, particularly when it comes to managing fire and smoke spread in buildings. The specific requirement for fire dampers at shaft penetrations depends on factors such as the type of duct and the distance it extends vertically.

In this case, if steel exhaust ducts extend vertically at least 22 inches, they may not require fire dampers at the shaft penetrations. This allowance is based on building codes and standards which often define the minimum vertical distance that ductwork must reach before the additional fire protection of dampers is deemed unnecessary. Thus, the 22-inch requirement serves to provide a level of safety while also allowing for practical installation and maintenance considerations.

Understanding this requirement helps HVAC professionals ensure compliance with local codes while effectively designing and implementing HVAC systems in a way that minimizes risks associated with fire and smoke.