SSV is an active engineering control employed to mitigate potential vapor intrusion (VI) for volatile organic compounds (VOCs) into buildings.

The author has participated in upgrading two ventilation systems that were originally designed to vent only radon at school sites but needed to also serve as vapor intrusion mitigation systems.

We provide tailored sub-slab ventilation systems for both new construction and retrofit applications. Our approach combines engineering expertise with field-tested installation practices to deliver …

H2K Sub Slab Blower systems are used to prevent intrusion of subsurface vapors such as radon, chlorinated, and petroleum (BTEX) vapors into inhabited buildings. These units are a very common …

Geiger builds sub-slab depressurization systems that use blower, fan, or vacuum pump-powered ventilation systems to lower sub-slab air pressure relative to indoor air pressure.

Oct 20, 2023 · Sub-membrane depressurization systems are installed at buildings with earthen or gravel crawl spaces or floors instead of slabs. A sub-slab depressurization system consists of PVC piping …

A sub-slab depressurization (SSD) active vapor collection system involves the use of a blower or electric fan. The installation of a suction pit or plenum in the sub-slab allows for contaminated vapors to rise …

SSD is the most common engineering control installed in buildings at or near vapor intrusion sites. The operational objective for SSD systems is to create a negative pressure below the building slab. …

EPA defines SSD technology as "a system designed to achieve lower sub-slab air pressure relative to indoor air pressure by use of a fan-powered vent drawing air from beneath the slab."

Dec 29, 2025 · A sub-slab ventilation system works by creating a controlled pressure differential beneath a building’s foundation, effectively drawing soil gases like radon or methane away from the structure …