In HVAC systems, which type of dampers are not approved for dynamic operations during a fire?

In HVAC systems, fire dampers are specifically designed to prevent the spread of fire within ductwork. They automatically close when a fire is detected, effectively compartmentalizing areas to inhibit fire movement. Non-labeled dampers are those that have not been tested or certified for fire resistance by a recognized testing agency, which means they do not meet the required standards for safety during dynamic operations associated with a fire scenario.

Using non-labeled dampers could compromise building safety since they might not function appropriately in a real fire situation, potentially allowing smoke and flames to propagate throughout the duct system.

On the contrary, other types of dampers, like smoke dampers or ceiling radiation dampers, are specifically designed with features that allow them to operate safely and effectively during dynamic operating conditions related to fire safety. Therefore, the use of non-labeled dampers in a fire scenario is not approved according to the building and mechanical codes, making them unsuitable for dynamic operations in cases of fire.