Radon Mitigation Fan & Pipe Sizing Calculator
Calculate active sub-slab radon mitigation fan class, sub-slab static suction pressure (in. w.g.), airflow CFM, 3" vs 4" PVC pipe sizing, and EPA radon reduction.
Calculated Results
Frequently Asked Questions
What is the EPA action level for indoor radon gas?
The US Environmental Protection Agency (EPA) strongly recommends installing an active radon mitigation system if indoor radon levels test at or above 4.0 pCi/L (picocuries per liter). Radon is the #1 leading cause of lung cancer among non-smokers in America.
How does an active sub-slab depressurization radon system work?
A continuous inline fan draws air from a suction pit dug beneath the concrete basement slab, creating negative air pressure under the house. Radon gas is captured before entering the living space and safely exhausted above the roofline.
How does sub-slab soil type dictate radon fan selection?
Clean crushed gravel allows air to move freely, requiring a low-suction, high-airflow fan (e.g., RadonAway RP145). In contrast, tight dense clay or compacted earth restricts airflow, requiring a high-suction, high-static pressure fan (e.g., RadonAway GP501 or Festa Radon Eagle).
What does a U-tube manometer indicate on a radon pipe?
A U-tube oil manometer mounted on the PVC pipe displays the pressure differential between the pipe interior and the basement. Unequal liquid levels confirm the fan is actively drawing negative suction pressure; equal levels mean the fan has failed or lost electrical power.