소방방재대학원(석사과정)

부착 높이에 따른 광전식 연기감지기의 작동시간 비교·분석

Comparative Study on the Response Time of Photoelectric Smoke Detectors at Different Installation Heights

Abstract This study utilized the PyroSim simulation program to analyze the operating time of smoke detectors according to their installation height, and it is designed to supplement the existing area-based installation standards. A combustible material was placed at the center of a 150 m² space, and the activation times of photoelectric smoke detectors installed at different heights were measured during a simulated fire. The Type 1 detector activated at 36.6 seconds when installed at 2.5 m and at 50.2 seconds at 19 m, showing a delay of approximately 13.6 seconds. The Type 2 detector exhibited a similar pattern but generally had longer activation times than the Type 1 detector. This delay is attributed to the slower rise and dispersion of smoke in spaces with high ceilings or large volumes, with particularly significant differences observed above 10 m. According to NFPA 72, the allowable coverage area per detector decreases as ventilation rates increase. Therefore, smoke detector design should comprehensively consider installation height, ventilation, spatial structure, and airflow. In large spaces with high ceilings or strong ventilation, reducing detector spacing or using high-sensitivity detectors is recommended. Detector selection should consider the space’s use and fire risk. As installation height and ventilation increase, fire detection may be delayed; therefore, rational design and area calculations accounting for these factors are necessary. This approach enhances fire safety in large and high-rise buildings and supports efficient fire alarm systems tailored to different risk levels.