sub-slab depressurization 2
https://radonsysteminstallationguide.hexaforgey.com/posts/understanding-radon-system-installation-cost-in-st.-louis
Sub-slab depressurization is a common method used to keep harmful soil gases like radon from entering homes by creating a vacuum beneath the concrete floor. A pipe is inserted through the slab, and a fan gently pulls air from the soil, which then vents safely outside. It's a quiet, low-maintenance system that protects indoor air quality without interfering with daily life.