Which of the following statements about air barriers is TRUE?

The statement regarding air barriers being continuous and well-sealed is true because proper air barrier systems are designed to minimize air leakage, thereby enhancing the overall energy efficiency of a building. Continuous air barriers ensure that there are no gaps or discontinuities through which air can flow, which can lead to unwanted energy loss, moisture problems, and reduced indoor air quality.

Well-sealed air barriers are crucial in controlling the flow of air in and out of the building. When air barriers are not continuous or well-sealed, potential leaks can occur, allowing outside air to infiltrate or conditioned air to escape. This can compromise the effectiveness of insulation, lead to increased energy costs, and potentially cause moisture accumulation within building assemblies, which can further lead to structural and health issues.

In contrast, the other statements do not accurately reflect the characteristics and functions of air barriers. Some air barriers do not permit air infiltration as part of their function, not all air barriers are designed to be waterproof, and smaller barriers may not necessarily be more effective than larger, continuous systems when it comes to overall air sealing.