What happens if a depressurization system fan is turned off?

When a depressurization system fan is turned off, it significantly impacts the system's operation and effectiveness in controlling radon levels in a building. The correct understanding of the implications of turning off the fan leads to the conclusion that the system will not function correctly in mitigating radon gas.

If the fan is off, the airflow that is designed to draw radon gas from beneath the building and vent it to the outside is halted. This lack of airflow means that the radon gas can accumulate within the living areas of the building, leading to potential exposure for the occupants. Thus, the system loses its effectiveness in reducing radon levels, and higher concentrations may lead to health risks.

The focus should be on how the fan's operation plays a critical role in maintaining air pressure differentials that facilitate the removal of radon. Therefore, the impact of the fan being turned off is that it can indeed allow radon levels to rise, creating a hazardous environment. This situation underscores the importance of ensuring that the depressurization system remains operational to effectively manage radon concentrations and protect health.