At what height should short-term testing devices be placed off the floor?

Short-term radon testing devices should ideally be placed at a height of 20 inches off the floor to provide the most accurate and reliable measurements. This height is recommended because it typically reflects the breathing zone of most occupants. Measurements taken too close to the ground may not accurately represent the radon concentration that people are actually exposed to, as radon levels can vary significantly with height due to air circulation patterns within the room.

Placing testing devices at 20 inches allows for the collection of data that is more representative of occupant exposure, making the results more relevant for assessing the potential health risks associated with radon. In contrast, devices placed lower than this can be influenced by floor materials and construction differences, while those placed much higher may not adequately capture the radon levels at which people spend most of their time. Therefore, the height of 20 inches strikes a balance that optimizes the data quality for short-term radon testing.