After installing a sub-slab suction system, what is the best way to reduce radon levels further?

Sealing openings in the slab closest to the suction point is the most effective method to enhance the performance of a sub-slab suction system. By sealing these openings, you reduce the influx of radon from the surrounding soil into the building. This minimizes the pathways that radon can use to enter the indoor environment, allowing the suction system to operate more efficiently by concentrating its efforts on drawing radon from the sub-slab area rather than allowing it to leak in from unsealed entries.

Furthermore, sealing enhances the pressure differential created by the suction system, further increasing its effectiveness in drawing radon-laden air from beneath the foundation and expelling it safely above the home. This targeted sealing approach focuses on the problem area and directly contributes to a more significant reduction in indoor radon levels.

The other options do not address the core issue as directly. For instance, increasing fan power might help if the system is underpowered, but it does not solve the problem of leakages from the slab. Changing to a larger vent pipe could potentially help with airflow but doesn’t necessarily address the entries of radon into the home. Testing for alternative radon sources may provide insight into other mitigation needs, but it does not contribute directly to reducing radon levels from the