What two conditions are necessary for air leakage to occur?

For air leakage to occur, two primary conditions must be present: a pressure difference and an opening. A pressure difference is crucial because it creates the driving force that moves air from an area of higher pressure to an area of lower pressure. This movement results in air leaking through any available openings.

An opening, which can be described as a hole or other form of breach in the barrier between the two pressure areas, allows the air to flow through. This opening does not have to be large; even small cracks, gaps, or holes can facilitate air leakage if coupled with a sufficient pressure difference.

In contrast, other options may include conditions that do not directly contribute to air leakage. For instance, an open window and a temperature variance may influence airflow but do not directly guarantee leakage without the requisite pressure difference. Similarly, a sealed area contradicts the premise of ‘leakage,’ as air must have a way to penetrate a seal.

Thus, the correct understanding of air leakage focuses on the interplay between pressure differences and openings, validating that option indicating a pressure difference and a hole is the most accurate.