Certified Energy Auditor Practice Exam

Which of the following is not a way moisture enters a building?

1. Capillary action

2. Air leakage

3. Vapor diffusion

4. Surface tension

The correct answer is: Surface tension

Moisture can enter a building through several physical processes, and understanding these processes is important for energy auditing and building performance evaluation. The correct choice indicates that surface tension is not a mechanism through which moisture enters a building. Capillary action refers to the ability of water to move through small spaces, such as those found in porous materials. This process allows moisture to be drawn into building materials, potentially leading to structural issues or mold growth. Air leakage is another significant pathway for moisture infiltration. Through cracks, gaps, and openings in a building envelope, moist air from outside can enter a building. This not only affects energy efficiency but can also introduce humidity, leading to condensation issues. Vapor diffusion is the movement of water vapor through materials due to differences in vapor pressure. This process occurs when water vapor moves from areas of high concentration to areas of lower concentration, allowing moisture to penetrate walls and ceilings. In contrast, surface tension is a property of liquids that allows them to resist an external force, seen in phenomena like droplets forming on a surface. However, it does not function as a mechanism for moisture entering a building. Hence, recognizing the distinct mechanisms for moisture movement helps in managing and preventing moisture-related issues in buildings.