What is the recommended timeframe for keeping a closed house condition during radon testing?

The recommended timeframe for maintaining a closed house condition during radon testing is typically at least 4 days. This duration is important because it allows the radon concentrations within the home to stabilize, leading to a more accurate measurement.

By ensuring that the house remains closed during this period—meaning windows, doors, and vents are kept shut, while avoiding activities that could introduce outside air—any influences from external air flow or changes in pressure are minimized. This is crucial because radon levels can fluctuate based on these variables.

Keeping the house closed for at least 4 days aligns with guidelines set forth by health agencies and radon measurement protocols, reflecting a balance between practical considerations and the need for reliable data. Shorter durations may not adequately capture the typical radon levels, while longer periods, while theoretically allowing for steadier results, can be impractical for homeowners.