Lufttætter

Lufttætter, often translated as airtightness or air barrier, refers to the measure of how well a building prevents uncontrolled air leakage. This uncontrolled leakage can occur through cracks, gaps, and openings in the building envelope, which includes the walls, roof, and foundation. Achieving good lufttætter is crucial for several reasons related to energy efficiency, indoor air quality, and the durability of the building structure.

In terms of energy efficiency, air leakage leads to significant heat loss during colder months and heat gain during warmer months. This forces heating and cooling systems to work harder, consuming more energy and increasing utility costs. A well-sealed building minimizes this unwanted exchange of air between the interior and exterior.

Regarding indoor air quality, uncontrolled air leakage can draw in pollutants from outside, such as dust, pollen, and exhaust fumes, or allow moisture to penetrate the building structure. Conversely, it can lead to the escape of conditioned air. By controlling air movement, building designers and occupants can better manage ventilation and ensure healthier indoor environments.

Furthermore, lufttætter contributes to the longevity of a building. Moisture that infiltrates through air leaks can condense within building materials, leading to mold growth, rot, and structural damage over time. A continuous air barrier helps to prevent such moisture-related problems. Building codes in many regions now specify requirements for air leakage rates, and testing methods like blower door tests are used to assess a building's performance.