Where should ASD fans not be installed?

ASD (Aeration System Design) fans should not be installed directly beneath occupiable space because doing so could potentially expose residents to any radon gas that may be present. The main purpose of an ASD system is to mitigate radon levels by venting it away from the living spaces of a home. If the fan is installed in a location that is directly below where people spend their time, it could inadvertently allow radon to enter the living area if there’s a failure in the system or if the fan malfunctions.

Installing ASD fans in areas like garages or crawl spaces is generally acceptable, since these are not typically occupied spaces and are located further away from where people live and work within the home. Attics can also be suitable for ASD fans depending on the overall design and ventilation of the mitigation system. Therefore, ensuring that fans are positioned away from occupiable areas is crucial for effective radon mitigation and maintaining a safe living environment.