blowerdoortesti

Blowerdoor testing is a method used to measure the airtightness of a building. This involves depressurizing or over-pressurizing the building by using a powerful fan mounted in an exterior doorway. The fan draws air out of the building, creating a pressure difference between the inside and outside. This pressure difference forces outside air into the building through any leaks or cracks in the building envelope.

The amount of airflow required to maintain a specific pressure difference is measured. This airflow rate, often expressed in cubic feet per minute (CFM) or cubic meters per hour (m³/h), is then used to calculate the building's overall airtightness. A higher airflow rate indicates a leakier building, while a lower rate suggests a more airtight structure.

Blowerdoor testing is commonly performed during construction or renovation to identify and quantify air leakage. It is a crucial step in assessing a building's energy efficiency, as uncontrolled air leakage can lead to significant heat loss in colder climates and heat gain in warmer climates. This, in turn, increases heating and cooling energy consumption and costs.

The results of a blowerdoor test can help pinpoint specific areas of leakage, such as around windows, doors, electrical outlets, plumbing penetrations, and attic hatches. This information allows builders and homeowners to make targeted improvements to seal these leaks, thereby enhancing the building's thermal performance, improving indoor air quality by reducing drafts and uncontrolled air infiltration, and potentially preventing moisture-related issues like mold growth. Building codes in many regions now mandate blowerdoor testing to ensure a minimum level of airtightness.