What should be avoided when placing detectors around a fan or HVAC system?

When placing radon detectors, it is crucial to avoid situations where air movement can distort the readings. Placing detectors in a draft of moving air is problematic because the airflow can carry radon gas away from the detector, leading to inaccurate measurements. This is particularly important because radon is heavier than air and tends to accumulate in low areas, so airflow can disrupt this natural behavior and result in readings that do not truly represent radon levels in the space.

Successful radon testing necessitates that the detector is stationary and in a location where it can accumulate radon over time without interference from external air currents. This ensures that the measurements reflect the actual concentration of radon in the environment being tested.

In contrast, increasing airflow around the detector or making positional adjustments every hour might also contribute to variability, but they do not pose the same level of direct interference as placing a detector in a draft of moving air. Similarly, direct placement in front of the fan could potentially enhance detection sensitivity but could result in similar inaccuracies if the airflow disrupts the measurement environment. Therefore, avoiding drafts is essential for accurate radon detection.