Auruläbilaskvuse

Auruläbilaskvuse, also known as vapor permeability, is a material property that describes its ability to allow water vapor to pass through it. This is a crucial characteristic for many building materials and products, influencing their performance and longevity. Materials with high auruläbilaskvuse are described as "auruläbilaskvad" or "aurutõkkega" in Estonian contexts, indicating they readily permit vapor to move. Conversely, materials with low auruläbilaskvuse are termed "aurutihedad" or "aurutõkkematerjalid," meaning they significantly impede vapor transfer.

The measurement of auruläbilaskvuse is typically expressed as a diffusion resistance factor (often denoted by the Greek letter mu, μ) or as a water vapor transmission rate (WVTR). A higher mu value indicates lower permeability. This property is particularly important in building construction to manage moisture within walls and other structures. For example, in cold climates, a well-designed building envelope will use materials with appropriate auruläbilaskvuse to prevent condensation from forming within insulation layers, which can degrade its thermal performance and lead to mold growth. Similarly, in packaging, controlling auruläbilaskvuse is essential for preserving the freshness and quality of food products by preventing moisture loss or gain.