LAUSR

The public interest in indoor air quality has rapidly increased in Korean society, and ventilation systems can play an essential role in improving indoor air quality. This study aims to estimate the reduction in indoor CO2 and radon, which can be effectively mitigated by air exchange, according to the operation of mechanical ventilation in an apartment with the national standard housing size (85 m2) and shape in Korea. The time required to meet Korea’s mandatory indoor CO2 standard (1000 ppm) was 167, 98, 66, and 51 min under air change rates of 0.5, 1.0, 1.5, and 2.0 ACH (air change per hour), respectively. Regarding indoor radon, the removal rate increased with increased ventilation volume, and the minimum concentration level was low and sustained for a prolonged duration. Nonetheless, an air change rate of 0.5 ACH may not offer sufficient ventilation. Additionally, it is imperative to note that indoor radon concentrations tend to escalate swiftly when a mechanical ventilation system is deactivated. Thus, to enhance indoor air quality, it is necessary to reconsider strategies to augment the air change rate and guarantee uninterrupted ventilation.