Active Soil Depressurization (ADS) This form of Radon mitigation is the most common type of system installed in the Northern Virginia area.
An ASD system is the preferred and typically the most effective method to reduce the Radon levels in homes that have a concrete floor in the basement or lowest level of the home. This method reduces radon gas entry by reversing the air pressure relationship between the indoors and the radon source beneath the concrete floor(the soil).
We start the process by performing a “pressure field communication test” to determine if the conditions underneath the concrete slab will be sufficient to draw the Radon gas through. (occasionally there is an adverse condition underneath the concrete floor that will not allow an ASD system to be effective. In these cases, the client will be informed and alternative options will be discussed).
After a successful communication test is achieved the installation of the ASD system will begin. The system consists of:
- A hole being drilled through the concrete floor (suction point), this is where the suction pipe will be installed.
- A PVC suction pipe will be run from the suction point to the exterior of the home.
- On the exterior of the home the in line Radon mitigation fan, electrical service disconnect (switch/ outlet) and discharge pipe will be installed.
- The system discharge pipe will extend to a minimum of 6” above the roof line.
- In some cases the system piping and fan may be installed in the attic of the home and discharging through the roof.