What is the performance requirement for materials in an air barrier system?

The performance requirement for materials in an air barrier system is indeed specified as 0.004 cfm/ft² at 1.56 ft./lbs. or 75 Pa. This value indicates the maximum allowable airflow through the air barrier material at a specific pressure differential, which is critical for ensuring that the building envelope effectively controls air leakage.

Maintaining low levels of air infiltration is essential for energy efficiency, indoor air quality, and comfort within the building. The specified rate highlights the importance of high-performance materials that can withstand various environmental conditions while preventing excessive drafts and energy loss.

In essence, this precise measurement ensures that the materials used in the air barrier system are capable of performing their intended function, contributing to the overall effectiveness of the air barrier in a building. This accuracy in airflow measurement is essential for achieving the building performance standards set forth by various building codes and guidelines.