What happens in the area below the neutral pressure plane in a home?

In a home, the area below the neutral pressure plane typically draws air into the home. This phenomenon occurs due to the differences in air pressure within the structure. When the neutral pressure plane is considered, it is essentially a level within a home where the air pressure transitions.

In areas beneath this plane, the air tends to be at a lower pressure compared to the exterior environment. As a result, air from outside is drawn in to equalize pressure differences. This is significant for radon measurement and mitigation because it can influence the levels of radon gas entering the home, particularly if the home has a basement or crawl space located below the neutral pressure plane.

The principle at play here is based on basic fluid dynamics, where air will flow from areas of higher pressure to areas of lower pressure. This behavior is crucial for understanding how air quality and contaminant entry, including radon, can be affected by the structure's airflow dynamics.