2. Active sub-slab or sub-membrane depressurization system
Consists of the following components:
Same system as the passive with the addition of an in-line fan – this is used to facilitate movement of soil gas through the pipe. Virtually all homes with an active system have radon levels below the 4 pCi/L level
The vent pipe must not be routed through an outside wall in colder climates. Running the pipe through the warmer part of the house will help to encourage the natural draft upward of air. This also provides more room for the installation of a fan should that be necessary.
Install the vent pipe in a vertical run with minimal bends and elbows.