Radon Mitigation Company Serving the Greater Virginia Region
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Radon Mitigation Techniques
Active Soil Depressurization: ASD
ASD reduces radon gas entry by mechanically creating a suction beneath the foundation which is stronger than the vacuum applied to the soil by the house. (Must remove air from beneath home at a faster rate than what air is supplied to it.) • ASD collects radon gas prior to entry and exhausts it to a safe location outside of the house. • Its application depends upon the foundation type, not radon concentrations.
ASD type of systems:
1- Sub-Slab Depressurization (ASD) system
This active sub-slab depressurization (ASD) system is by far the most common type of radon gas reduction system installed today. A hole is cut in the basement slab, a cavity is excavated beneath the slab, and 3" or 4" diameter PVC pipe is run up from the slab, out the basement wall, and connects with an exterior mounted exhaust fan. From the fan, an exhaust pipe runs up at least 10 feet above ground level, 10 feet from or 2 feet above any windows.
2- Submembrane Depressurization (SMD) system.
SMD Air extracted from beneath a well sealed sheet of plastic (High density polyethylene sheet) laid on earthen areas such as crawlspaces. The air is exhausted from crawl space before radon gas in crawl space can enter living space above by installing a ventilation system through polymer sheeting in crawl space, up through interior or exterior of house/building to radon fan vented above the roof line.
There are several techniques that can be used to reduce radon gas levels inside in
• The most common system installed is known as a "sub-slab depressurization system". It is very effective. A vacuum
is created under the basement floor or slab and captures the radon gas before it enters the house space. The fan characteristics,
placement of suction points, and quantity of vacuum pits are unique to each property and must be designed accordingly.