How does an air barrier affect the flow of heat, air, and moisture?

An air barrier plays a crucial role in controlling the flow of air, heat, and moisture in a building. By limiting the movement of air, an air barrier effectively reduces unwanted drafts and infiltrations, which can lead to energy loss and increased heating or cooling demands. This containment helps maintain a stable indoor environment and maximizes energy efficiency.

In addition to controlling air flow, an air barrier also slows down heat transfer. By restricting the passage of air, it helps minimize convective heat loss in winter and reduces heat gain in summer, maintaining comfortable indoor temperatures without excessive reliance on HVAC systems.

Moisture management is another critical function of an air barrier. By controlling the air movement, it prevents moist air from entering the building envelope, which can lead to condensation, mold growth, and structural damage. As a result, the integrity of the building is preserved while promoting overall energy performance.

The other options misunderstand the primary purpose of an air barrier. Some suggest that it enhances air and moisture movement or only manages heat, which misrepresents the comprehensive function of an air barrier as a critical component for building performance and sustainability.