BPI Building Analyst Practice Test

When more air enters the home through leaky ducts than is being expelled, it results in a scenario known as positive pressure. This is because the influx of air is greater than the outflow, creating an excess of air within the building's envelope. In structures with a positive pressure, air is forced out of the building through any openings, which can lead to issues such as increased energy costs and potential moisture problems, as conditioned air escapes while unconditioned air can enter. On the contrary, negative pressure occurs when there is more air exiting the home than is coming in, which can pull air from outside through any leaks, while neutral pressure indicates a balance of air entering and exiting. Equalized pressure suggests a situation where the pressures inside and outside the building are the same. In this context, since the dominant condition is that more air is flowing in than out, positive pressure is definitively the correct characterization of the pressure created.