Radon Fan Below Habitable Room – DEFECT
If you see a radon system/fan that is below a habitable room the inspector should call this out as a defect. There could be radon gas that is getting sucked from the crawl space or from under a slab, and if there is a leak in the system after the fan you would be filling the home with radon gas. It is better for the fan to be located outside because when it is inside the home it is under negative pressure. Once again, if you see this while inspecting a home, make sure to call it out as a defect in your report.