At which pressure must the air leakage rate be reported according to ASTM E1827 - 11?

The air leakage rate must be reported at a pressure of 50 Pa as specified by ASTM E1827 - 11. This standard is a key reference in the field of building airtightness testing, particularly as it establishes a consistent pressure level that allows for comparability across different tests and buildings.

Measuring the air leakage at 50 Pa helps to create a standardized approach for evaluating building envelope performance, ensuring that the results reflect the pressure conditions that are commonly experienced in typical operational scenarios. This pressure level represents a reasonable condition to simulate the air pressure differential that a building experiences under various weather conditions and wind pressures, making it a practical choice for testing.

By reporting the air leakage rate at this specified pressure, practitioners provide a reliable metric that can inform design, construction practices, and energy efficiency assessments, ultimately contributing to improved building performance and occupant comfort.