What is a necessary condition for radon testing after installation of a mitigation system?

For effective radon testing after the installation of a mitigation system, it is essential to perform the test in the nearest occupiable area. This is because the purpose of the test is to evaluate the functioning of the mitigation system in providing a safe living environment by reducing radon levels. By testing in the closest occupied space, you can quickly assess whether the system has successfully reduced radon concentrations where people are likely to spend significant amounts of time. Additionally, results from the nearest area will reflect the immediate effectiveness of the mitigation efforts.

Testing in the farthest room is less practical, as it may not accurately represent conditions in the areas where occupants spend most of their time. Immediate testing after installation may not properly evaluate the effectiveness of the system since it may require some time to stabilize the indoor air quality and radon levels. Testing too soon might yield misleading results about the system’s performance. Thus, focusing on the nearest occupiable area allows for a more relevant and accurate assessment of radon levels after mitigation efforts have been made.