Active Soil Depressurization (ASD) System

A Sub-slab Active Soil Depressurization System usually has one suction point and is installed in the basement to mitigate radon in air.  Schedule 40 PVC piping is used to vent the radon gas out of the house.  A RadonAway series fan draws out the radon gas venting it to the air above the home. The radon gas will quickly dilute into the atmosphere.  A pressure sensing device, located in a place visible to the homeowner, is installed to monitor the performance of the system. System performance is dependent upon air space and soil conditions located under the slab.  If inadequate suction is obtained under the slab, then additional suction points may be needed.

Active Soil Depressurization (ASD) Fans

RadonAway® RP/ GP series radon mitigation fans are intended for use as a component of an active soil depressurization (ASD) system for reducing radon, other soil gases and moisture. The popular RP series provides high air flow and is one of the most energy-efficient radon mitigation fans available. The GP series provide versatility and a broad performance range focusing on drawing pressure in moderate to tight soils when less air movement is necessary and are ideal for use when multiple suction points are necessary.


Energy efficient; Ultra-quiet operation; Meets all electrical code requirements; Water-hardened motorized impeller; Seams sealed under negative pressure to inhibit radon leakage; ETL Listed - for indoor or outdoor use; Thermally protected motor; Rated for commercial and residential use

Active Soil Depressurization (ASD) System

What is Radon?

Radon occurs naturally in the air both inside and outside your home. It is the concentration level present in your home that will determine if action should be taken to reduce the level to the EPA guidelines. Testing is the only way to accurately measure the radon level in the water and air. Radon testing is relatively inexpensive and can be done quickly.

A Citizen’s Guide to Radon