What is the primary purpose of an air barrier in construction?

The primary purpose of an air barrier in construction is to help control heat and moisture flow within a building. By effectively sealing gaps and cracks in the building envelope, air barriers prevent the exchange of air between the inside and outside environments. This control is crucial for several reasons.

First, managing heat flow contributes to energy efficiency. An effective air barrier reduces unwanted heat loss in colder months and limits heat gain during warmer months, ultimately helping to maintain a comfortable indoor temperature and reduce HVAC energy consumption.

Second, controlling moisture flow is vital for preventing condensation, which can lead to mold growth, wood rot, and degradation of building materials over time. Proper air barrier installation helps protect the building’s structural integrity and indoor air quality by minimizing potential moisture issues.

While preventing pest intrusion, reducing noise pollution, and providing structural support are essential concerns in construction, they are not the primary functions of an air barrier. The key focus of an air barrier is on the management of heat and moisture flow, making option B the correct answer.