What is the baseline pressure requirement according to ISO 9972:2015?

The baseline pressure requirement according to ISO 9972:2015 is established to ensure accuracy and consistency during airtightness testing. A baseline pressure of less than or equal to 5 Paschals (Pa) is essential because it represents a controlled environment that minimizes the effects of external wind pressures and thermal buoyancy. By adhering to this standard, testers can achieve reliable results that reflect the actual airtightness performance of the building under normal conditions.

This specific threshold supports the integrity of the testing process, as pressures above this level could introduce errors in measuring air leakage rates due to the influence of fluctuating external conditions. Maintaining the baseline pressure within established parameters is crucial for validating the airtightness performance of buildings and ensuring compliance with energy efficiency and building codes.