What is the airflow recommended per the standard at 12.5 Pa?

The correct recommended airflow at a pressure difference of 12.5 Pa is indeed specified as 0.070 m³/s (148 cfm). This value serves as the baseline for evaluating the airtightness of buildings. The standard emphasizes this level of airflow to provide a clear benchmark for assessing energy efficiency and air quality within buildings. Achieving or maintaining this airflow indicates that the building's envelope is relatively tight, which is crucial for reducing energy loss due to air leaks, controlling indoor moisture levels, and ensuring proper ventilation strategies.

By establishing this specific airflow rate at 12.5 Pa, the standard helps practitioners identify which buildings meet performance criteria and how effectively they manage air movement, which is a critical aspect of sustainable building design and operation. Other airflow values presented are higher, indicating that they would represent less airtight conditions, which may not align with the focus of the standards on enhancing overall building performance and energy efficiency.