What must be utilized if there is an obstruction or buildup in a duct?

In situations where there is an obstruction or buildup in a duct, the use of a test mandrel is essential. A test mandrel is a specialized tool designed specifically for assessing the internal diameter of ductwork and identifying any restrictions or blockages. When inserting the mandrel, it allows the technician to detect areas where the airflow may be compromised due to clogs, bends, or other obstructions. This ensures that the duct can maintain its intended airflow efficiency.

By utilizing a test mandrel, you can also gain insight into the overall health of the duct system and whether it adheres to the necessary specifications for optimal performance. The other options, while useful in different contexts, do not directly facilitate the identification or evaluation of obstructions in ductwork. An inspection camera can help visualize issues but doesn't address blockages quantitatively. A drainage system is unrelated to duct obstructions, and additional ducting simply expands the system without resolving existing blockage issues.