At what pressure does ASTM E1258 specify airflow of 0.760 m^3/s?

The correct answer is based on the guidelines set forth in ASTM E1258, which defines the conditions under which airflow measurements are to be taken for the purpose of whole-building airtightness testing. The standard specifies certain pressure levels at which airflow rates are to be reported, and in this case, it indicates that an airflow of 0.760 m³/s corresponds to a pressure of 75 Pa.

This pressure level is significant as it allows for consistent measurements across different buildings and testing environments, ensuring that results are comparable. Therefore, knowing the airflow rate at this specific pressure aids in assessing a building's airtightness performance effectively. The reference to 75 Pa in ASTM E1258 suggests that most standard tests are conducted at this pressure to evaluate how well a structure resists air leakage, which is a key factor in energy efficiency and overall building performance. Understanding airflow at this pressure is essential for professionals involved in building science, energy auditing, and code compliance.