luftbarrier

Luftbarrier is a German term that translates to "air barrier" in English. In the context of building science and construction, an air barrier is a continuous layer of material or a system of materials that prevents or controls the movement of air through the building envelope. This envelope comprises all the components that separate the conditioned interior of a building from the unconditioned exterior, including walls, roofs, foundations, and fenestrations.

The primary function of an air barrier is to reduce uncontrolled air leakage, also known as air infiltration and exfiltration. Air leakage can lead to several problems. It can cause significant heat loss or gain, increasing energy consumption for heating and cooling. It can also carry moisture into building assemblies, leading to condensation, mold growth, and material degradation. Furthermore, air leakage can compromise indoor air quality by allowing pollutants from the outside to enter the building or by drawing conditioned air out.

Effective air barrier systems are crucial for achieving energy efficiency, durability, and occupant comfort in buildings. They are typically comprised of specific materials like continuous membranes, sheathing, tapes, and sealants that are carefully installed and detailed to ensure continuity at all joints, penetrations, and transitions. The performance of an air barrier is often measured through air leakage tests, such as blower door tests. Building codes in many regions now mandate the implementation of air barrier systems to meet energy performance standards.