A duct system having all transverse joints and longitudinal seams sealed is a:

A duct system having all transverse joints and longitudinal seams sealed is a:

• A. Class B
• B. Class A
• C. Class C
• D. Class D

Answer: (A)

The main idea is duct leakage classification based on how well joints are sealed. When every transverse joint between duct sections and every longitudinal seam along the length of the duct is sealed, the system becomes the tightest possible, which is described as Class A. Sealing both types of joints eliminates leakage paths around the circumference and along the length, so nearly all the designed air is delivered to its destination rather than escaping through joints. This level of sealing represents the highest standard for low leakage and energy efficiency. If joints aren’t fully sealed, air can escape at the joints, and the system would be categorized as a lower leakage class, reflecting more leakage and less efficiency.

The main idea is duct leakage classification based on how well joints are sealed. When every transverse joint between duct sections and every longitudinal seam along the length of the duct is sealed, the system becomes the tightest possible, which is described as Class A. Sealing both types of joints eliminates leakage paths around the circumference and along the length, so nearly all the designed air is delivered to its destination rather than escaping through joints. This level of sealing represents the highest standard for low leakage and energy efficiency. If joints aren’t fully sealed, air can escape at the joints, and the system would be categorized as a lower leakage class, reflecting more leakage and less efficiency.