Ilmanpitävyys

Ilmanpitävyys refers to the ability of a building envelope to prevent uncontrolled air leakage. This airtightness is crucial for energy efficiency, occupant comfort, and the durability of the building structure. Uncontrolled air movement through cracks and gaps in the building envelope can lead to significant heat loss in winter and heat gain in summer, increasing energy consumption for heating and cooling.

Beyond energy, air leakage can also impact indoor air quality. Pollutants from the outside can infiltrate the building, and conditioned indoor air can escape, leading to drafts and uneven temperatures. In humid climates or during colder months, uncontrolled air movement can carry moisture into building cavities, potentially causing condensation and leading to mold growth and structural damage over time.

Achieving good ilmanpitävyys is typically done through careful design and construction practices. This involves using continuous air barriers, sealing all joints, penetrations, and interfaces within the building envelope. Common materials for air barriers include specialized membranes, tapes, sealants, and even certain types of sheathing and plaster. Testing for air leakage, often using a blower door test, is a standard method to assess the effectiveness of the air barrier system and identify areas that require improvement. A well-sealed building contributes to a more comfortable, healthy, and sustainable indoor environment.