Which component of a fireplace must be positioned not less than 8 inches above the fireplace opening?

The component of a fireplace that must be positioned not less than 8 inches above the fireplace opening is the damper. The damper plays a crucial role in controlling airflow in the chimney system. Its primary function is to open and close to allow smoke and gases to exit the fireplace when in use, while preventing cold air from entering the home when the fireplace is not in operation.

Placing the damper at least 8 inches above the fireplace opening helps ensure that it effectively manages airflow while also allowing for proper ventilation. This positioning is important for safety and efficiency, as it reduces the risk of smoke spilling back into the room and ensures that the chimney functions properly during the combustion process.

The other components serve different purposes: the firebox is the enclosure where the fire is built; the lintel is a structural support above the fireplace opening; and the cleanout is an access point for the removal of soot and debris from the flue. Each of these components has specific requirements, but none have the same airflow control function as the damper, nor do they share the same minimum height requirement above the fireplace opening.