D09 · Passive-to-active radon system conversion

ALT TEXT
Side-by-side diagram comparing a passive radon vent with an active system after adding a fan, pressure indicator, and testing requirement.

LONG DESCRIPTION
Two side-by-side schematics compare a passive new-construction vent with an activated system. The active side adds an in-line fan, pressure or warning indication, and post-mitigation radon testing. The drawing does not assert that every passive riser can be activated without evaluation. An Iowa note states that passive-to-active conversion requires a credentialed person under Chapter 44.

Source basis: Iowa Administrative Code 641—Chapter 44, effective 2026-07-01; ANSI/AARST CCAH listing for fan-ready new construction.
