What is the minimum requirement for the placement of the vent system exhaust point to prevent radon re-entrainment?

The minimum requirement for the placement of the vent system exhaust point to prevent radon re-entrainment is 20 feet. This distance is significant because it helps ensure that any radon gas being expelled from the exhaust does not re-enter the building through windows, ventilation systems, or other openings nearby.

Proper placement of the exhaust point at this distance minimizes the risk of the radon gas mixing back into the indoor air, thereby maintaining a safer environment within the home or building. This standard is based on guidelines that take into account typical wind patterns and the dispersal of gases. Maintaining a minimum distance of 20 feet helps reduce the impact of re-entrainment and is a crucial aspect of effective radon mitigation strategies.

In contrast, distances less than this could potentially allow for the reintroduction of radon into the premises, which is undesirable for safety and health reasons.