Red Seal Sheet Metal Worker Practice Exam

How is duct leakage typically tested?

1. Using a thermal imaging camera

2. Using a blower door test

3. Using pressure sensors

4. Using visual inspection

The correct answer is: Using a blower door test

Duct leakage testing is primarily conducted using a blower door test, which is designed to measure the air-tightness of a building's envelope, including its duct system. This method involves the installation of a powerful fan in an exterior door frame to induce air flow through the building. When the fan is turned on, it creates a pressure difference between the inside of the building and the outside environment. This pressure difference allows for the detection of air leaks within the ductwork. The results of the blower door test can indicate how much air is escaping from the ducts and help identify specific areas that require sealing or other improvements. This test is comprehensive and effective in quantifying duct leakage, making it a preferred method among professionals in the field. While other methods like thermal imaging, pressure sensors, and visual inspection can provide insights into duct performance or detect specific leaks, they are not as effective or quantitative in measuring overall duct leakage when compared to the blower door test.