What does the abbreviation "Pa" stand for in the context of air leakage testing?

The abbreviation "Pa" stands for Pascals, which is the SI unit of pressure. In the context of air leakage testing, Pascals are used to measure pressure differences across a building's envelope, which is crucial for determining the airtightness of the structure. This measurement is essential during tests like the blower door test to quantify how much air leaks through the building’s fabric. The value is expressed in Pascals, providing a clear and standardized way to represent and analyze the pressure exerted by air movement in and out of a building, thereby enabling effective comparisons and compliance with building performance standards.