This experiment evaluated the efficiency of mechanical ventilation, one of the measures to reduce indoor radon concentration in residential spaces. In the most popular ventilation rates of the air conditioning system, the most efficient air conditioning system was confirmed by checking the time when the radon concentration reached the lowest level, the radon reduction rate, and the radon concentration that could be lowered as much as possible. The results showed a reduction rate of up to 80% or more as a result of conducting the experiment by blocking the inflow of outside air. It was confirmed that the time to reach the lowest concentration after starting the mechanical ventilation was about 6 hours to a maximum of 7 hours. Therefore, this study verified that indoor radon concentrations can be efficiently reduced by using a mechanical ventilation system.

Abstract
1. 서 론
2. 실험방법
    2.1 실내공간 라돈 방출율 실험 체계 구축
    2.2 건축자재 라돈 방출율 측정 및 계산
3. 결 과
    3.1 Open test, 미풍(0.3회/h) 실험
    3.2 Close test, 미풍(0.3회/h) 실험
4. 결 론
References

• 김민준(연세대학교 환경공학과) | Min-Jun Kim (Department of Environmental Engineering, Yonsei University)
• 조승연(연세대학교 환경공학과) | Seung-Yeon Cho (Department of Environmental Engineering, Yonsei University) Corresponding author