Where must radon detectors be positioned in relation to the floor?

Radon detectors are ideally positioned above 20 inches from the floor to ensure accurate measurements of radon levels in a living space. This height allows the detector to be placed in an area where it can effectively assess the air quality that occupants are breathing, as most human activity occurs at this elevation.

Placing detectors too close to the floor could lead to inaccurate readings due to potential interference from household items or fluctuations in air currents near the ground. Additionally, positioning detectors higher than 20 inches optimizes their ability to capture the movement of radon gas, which can accumulate in various parts of a room but is particularly critical to monitor within the breathing zone of occupants, generally defined as the area between approximately 20 inches and 72 inches off the ground.

Understanding the reasoning behind the placement guidelines helps ensure that radon testing reflects the actual exposure risk, facilitating proper mitigation if necessary.