What would the radon level be if a home has a long-term radon level of 10 pCi/L and the air exchange rate is increased from 65 cfm to 120 cfm?

To determine the new radon level when the air exchange rate is increased, it's important to understand the relationship between air exchange rate and radon concentration. Increasing the air exchange rate reduces the concentration of radon within the home by diluting the radon gas with fresh air.

The initial long-term radon level is given as 10 pCi/L. Increasing the air exchange rate from 65 cfm to 120 cfm represents a significant increase in ventilation, which affects the accumulation of radon in the indoor air.

The formula to calculate the new radon level based on the change in air exchange rate involves understanding how the dilution process works. The increase in air exchange rate will proportionally lower the radon concentration, moving it closer to the baseline concentration determined by the ventilation rate. As a rule of thumb, a doubling of the air exchange rate can lead to significant reductions in radon levels.

In this case, an increase from 65 cfm to 120 cfm (which is roughly an 85% increase) would not double the ventilation but notably enhance the ventilation effect. Using the rule of thumb and calculations typically yields a new radon concentration around 5.4 pCi/L, which reflects the reduced levels due to the