What must be done before a leakage test can be performed?

Before conducting a leakage test, it's essential to ensure that several specific conditions are met to obtain accurate and reliable results.

Having all dampers open ensures that there are no restrictions in the airflow, which might interfere with the test results. This condition allows for a clear flow of air that can be monitored for leaks accurately.

The requirement for sealant to be dry is critical because if the sealant is still wet, it may not provide a proper seal, leading to false readings. A fully cured or dry sealant ensures that the joints are securely sealed, allowing for an accurate assessment of the system's integrity.

Blanking off the test section is another necessary step that prevents air from escaping through unintended openings outside of the test area. This isolation helps focus only on the section being tested, ensuring that any leaks detected are indeed from that specific portion of the system instead of other areas.

By adhering to all these prerequisites, the leakage test can provide a valid assessment of the air-tightness of the duct system, ensuring that it is installed properly and functions efficiently.