Vízpáráteresztés

Vízpáráteresztés refers to the ability of a material to allow water vapor to pass through it. This property is crucial in various applications, particularly in construction and textiles. In buildings, materials with good water vapor permeability, often referred to as breathability, help manage moisture within the building envelope. This prevents the buildup of condensation, which can lead to mold growth, material degradation, and reduced thermal performance. Examples of water vapor permeable materials in construction include vapor-permeable membranes, certain types of insulation, and some types of plasters and paints.

In the context of textiles, water vapor permeability relates to how well a fabric allows moisture, such as sweat, to escape from the body. This is essential for comfort, especially during physical activity. Fabrics designed for sportswear or outdoor gear often incorporate technologies or specific fiber structures to enhance their water vapor permeability, keeping the wearer dry and comfortable. The measurement of water vapor permeability is typically expressed in terms of the rate at which water vapor can pass through a given area of material over time, under specific conditions. This property is distinct from waterproofing, which refers to a material's ability to prevent liquid water from passing through. A material can be both waterproof and water vapor permeable, allowing it to protect against rain while still allowing moisture vapor to escape.