What is NOT a method of protecting duct systems that penetrate non-fire rated floor assemblies?

The method of protecting duct systems that penetrate non-fire rated floor assemblies includes various techniques specified in building codes to ensure that fire does not spread through these openings.

An air pressure test is not a protective method for duct systems in this context. Instead, air pressure tests are generally conducted to ensure that duct systems are sealed properly and do not have leaks that could affect air quality or system efficiency. While important for system performance, they do not provide fire protection.

In contrast, options like a shaft enclosure, which creates a fire-resistive barrier around the ducts, and the installation of a fire damper, which automatically closes to block fire and smoke, are appropriate methods for safeguarding duct systems. Connecting to no more than two stories is another code requirement aimed at limiting the potential spread of fire.

Understanding these protective measures is essential for compliance with safety standards in building design and construction.