How long after activating a mitigation system fan should a short-term test be conducted?

Conducting a short-term radon test after activating a mitigation system fan is an important step to ensure that the system is functioning properly and effectively lowering radon levels. The recommended timeframe for conducting this test is 24 hours after the activation of the fan.

This period allows sufficient time for the mitigation system to stabilize and for the air within the building to circulate and reach a new equilibrium state. Testing too soon, such as within 12 hours, may not provide an accurate measurement of the radon levels because the system may not have had enough time to influence the indoor environment fully. Conversely, waiting too long, like 36 or 48 hours, could delay the assessment of the mitigation system’s performance, potentially missing the opportunity to make timely decisions about any necessary adjustments to the system.

By following the 24-hour guideline, testing can yield results that truly reflect the effectiveness of the radon mitigation system, allowing homeowners and professionals to confidently gauge whether further action is needed.