Ventilation Behaviour Changes by Employing Environmental Monitoring Systems in Schools in Japan

Measurements and questionnaires were conducted mainly at an old elementary school employing no mechanical ventilation equipment in Japan to evaluate the effects with use of environmental monitoring systems set in the classrooms on the occupants’ ventilation behaviour. Indoor carbon dioxide concentration, air temperature and relative humidity were obtained by using the monitoring systems. The monitoring system has LED lamps indicating the indoor carbon dioxide concentration levels, which are below 1,000 ppm, between 1,000 ppm to 1,500 ppm and larger than 1,500 ppm. The measurements were operated with and without using the LED lamp operation. Measurement and questionnaires result obtained during winter of 2021 to 2022 indicates that the LED lamp served as a criterion for decision-making on ventilation behaviour. At the same time, the carbon dioxide concentration exceeding frequency of the standard level of 1,000 ppm is decreased in many classrooms during the LED using periods. In some classrooms, ventilation activities of opening the windows were limited by watching the LED until the carbon dioxide concentration was just below 1,000 ppm. Therefore, the measurement result showed also that the thermal environments were improved to warmer conditions. Furthermore, the voluntary involvement of children in opening/closing windows for ventilation were increased.