I have tried to find the answer, but cannot. Maybe you know: is sand an acceptable medium under the slab? Or does it have to be stone? And if radon is heavier, why don't we vent underslabs to gravity, just like we do with water?
Sand could work too, you just may need a higher powered fan compared to gravel to get the same amount of communication for the furthest reaches under the slab from your suction point. The sand will be more densely packed than gravel. I hear they need pretty big fans in environments with clay for example. Airborne radon is intermingled within the working fluid (air) which is relatively "light" such that differential pressure between outside/inside your house or temperature based stack effect can "overpower" gravity's effect allowing radon to accumulate inside a house. In Bernoulli's equation the pressure terms in this example heavily outweigh the potential energy terms and are the leading cause of the airflow. The goal of sub slab radon mitigation is to provide a path of lesser resistance for the air under your home instead of going into your home!
I have tried to find the answer, but cannot. Maybe you know: is sand an acceptable medium under the slab? Or does it have to be stone? And if radon is heavier, why don't we vent underslabs to gravity, just like we do with water?
Sand could work too, you just may need a higher powered fan compared to gravel to get the same amount of communication for the furthest reaches under the slab from your suction point. The sand will be more densely packed than gravel. I hear they need pretty big fans in environments with clay for example.
Airborne radon is intermingled within the working fluid (air) which is relatively "light" such that differential pressure between outside/inside your house or temperature based stack effect can "overpower" gravity's effect allowing radon to accumulate inside a house. In Bernoulli's equation the pressure terms in this example heavily outweigh the potential energy terms and are the leading cause of the airflow.
The goal of sub slab radon mitigation is to provide a path of lesser resistance for the air under your home instead of going into your home!
@@goodvibezgarage3232 GREAT INFO!