What defines vapor diffusion?

Vapor diffusion is defined as the transfer of water vapor through a material due to differences in vapor pressure. This process occurs when there is a higher concentration of water vapor in one area compared to another, leading to the movement of moisture from the area of higher vapor pressure to one of lower vapor pressure. This principle is crucial in understanding how moisture migrates within different building materials during drying processes.

This understanding is fundamental for professionals in the field, as it affects how drying strategies are implemented. For instance, if a material is exposed to a humid environment, moisture will migrate into it via vapor diffusion, whereas if that material is placed in a drier condition, moisture will migrate out. Recognizing the driving forces of vapor diffusion aids in planning effective drying methods and managing moisture retention in materials.