True or False: All pressure taps should cross from inside to outside at the bottom of the building.

The assertion that all pressure taps should cross from inside to outside at the bottom of the building is true because it aligns with the best practices for measuring airtightness during a Whole-Building Airtightness Test (WBAT). Positioning the pressure taps at the bottom allows for more accurate readings of the pressure differentials that occur when the building is subjected to varying pressure conditions. This placement facilitates the proper assessment of air leakage; as the lower zones are typically where most air leaks can occur due to pressure differentials created by wind or stack effects.

Moreover, having the pressure taps positioned in this manner ensures that the readings reflect the conditions as experienced by the building itself, capturing the full airflow dynamics from inside to outside. This standard is crucial for achieving reliable and consistent test results.

While pressure tap placement might vary according to specific testing circumstances or designs, the general requirement for them to cross at the bottom is a fundamental aspect of maintaining the integrity and validity of the airtightness testing process.