Only __________ dampers and __________ dampers labeled for use in dynamic systems shall be installed in HVAC systems designed to operate with fans on during a fire.

In HVAC systems designed to operate with fans during a fire, it is critical to use the correct types of dampers to ensure the safety and functionality of the system. The correct choice emphasizes the importance of using fire dampers and ceiling radiation dampers, which are specifically engineered to handle the unique challenges posed by smoke and heat in such scenarios.

Fire dampers are designed to close automatically in the presence of heat, thereby preventing the spread of fire through ductwork. Ceiling radiation dampers serve a similar purpose by restricting the transfer of heat from smoke and flames in ceiling spaces, where ductwork may be present.

The ability to contain smoke and limit its spread is vital in ensuring the safety of both emergency responders and building occupants during a fire incident. Therefore, using both fire dampers and ceiling radiation dampers aligns with the best practices established in fire safety and HVAC design, ensuring that systems operate safely and comply with relevant regulations.