A Positive Pressure Test, also known as a pressurisation test, is a diagnostic procedure used to assess the airtightness and integrity of a building’s envelope. It involves pressurising the interior of the building with a blower door or other pressurisation equipment to create a positive pressure differential relative to the outside.
During a Positive Pressure Test, the blower door fan is set up to blow air into the building, increasing the pressure inside. By measuring the airflow required to maintain the desired pressure difference, the test can determine the level of air leakage and identify any areas of concern.
The primary purpose of a Positive Pressure Test is to assess the ability of the building envelope to resist the infiltration of outdoor air. By pressurising the interior, potential air leakage pathways, cracks, gaps, or openings in the building envelope are exposed, allowing for their detection and quantification.
The results of a Positive Pressure Test are typically reported as the air changes per hour (ACH) or the Leakage Rate Index (LRI), indicating the volume of air that enters or escapes the building per hour per unit of building envelope area.
Positive Pressure Testing is commonly used in airtightness assessments, energy audits, and building performance evaluations. It helps identify air leakage points, evaluate the effectiveness of air sealing measures, and guide improvements in energy efficiency and indoor comfort.