What type of system is best for reducing radon levels in a building?

The sub-slab depressurization system is the most effective method for reducing radon levels in a building. This system works by creating a vacuum beneath the foundation of the structure, which prevents radon gas from entering the building. It involves installing a fan that draws air from beneath the foundation and vents it outside. By reducing the air pressure in the sub-slab area, the system effectively mitigates the natural flow of radon gas from the soil into the living space above.

The reason for the superiority of this system lies in its targeted approach to addressing the specific dynamics of how radon enters buildings. Since radon typically emanates from the soil, controlling the pressure differential can significantly lower concentrations of radon before it has a chance to disperse into indoor air.

In contrast, other systems such as air purifying, ventilation, and air ionization focus on altering indoor air quality but do not directly address or mitigate the entry of radon from the ground. These methods might improve overall air quality or reduce particulate matter but lack the specific design needed to effectively reduce radon concentrations.