FIELD SURVEY ON THE ACTUAL CONDITIONS AND IMPROVEMENT OF INDOOR TEMPERATURE AND HUMIDITY IN KINDERGARTENS IN GIFU AREA DURING WINTER

Abstract

Kindergarten is one of the main living spaces for infants, and its indoor environment is important from the viewpoint of maintaining and promoting health. In this research, we conducted a survey of indoor temperature and humidity environment in winter in kindergartens located in the Gifu area, clarified its characteristics, and examined the relationship between the kindergarten teacher's awareness of indoor environment adjustment and actions. In addition, we proposed a method to improve the humidity environment based on the results, and aimed to clarify the relation between the influence on the humidity environment and the window opening ventilation. Firstly, in 2006 school year, we selected nine kindergartens and measured indoor temperature and relative humidity with the aim of grasping actual conditions of temperature and humidity environment during winter in the classroom which were usually used by children. Measurement objects were about two classrooms of each kindergarten, totaling 17 rooms. There was no humidifier and mechanical ventilation in these rooms. Next, in 2007 school year, we examined the influence on humidity environments by humidification and window-opening ventilation behavior by kindergarten teachers in seven classrooms in six kindergartens, for the purpose of improving the humidity environment without the building repair. Finally, in 2008 school year, in order to grasp the state of ventilation, we measured the concentration of carbon dioxide and recorded the opening and closing state of doors and windows in three rooms in two kindergartens. The time zone analyzed temperature, humidity and carbon dioxide concentration were from 8: 30 to 14: 30 on weekdays. The results of the survey in 2006 school year, the absolute humidity in the classroom tended to be low in January and February, and it was thought that the influence of the dry outdoor absolute humidity was greatly received. As one of the factors, it was thought that kindergarten teacher gives priority to ventilation. As a main factor, it was thought that kindergarten teacher gave priority to ventilation. Based on the results of the survey in 2007 school year, it was inferred that using humidifier was effective in raising the absolute humidity of the classroom, even if differences in outdoor temperature and humidity conditions and window opening ventilation conditions by teachers were taken into consideration. According to the survey results in 2008 school year, the average carbon dioxide concentration in each classroom was below 1500ppm. The number of air changes was estimated and the dairy average was 1.7 to 5.3 [1/h]. From the records of the opening area of the opening and the number of children in the classroom, it seems that the time when all the children stayed in the room was short and all the opening of the room was not closed for a long time. Consequently, there is a possibility that the amount of ventilation required in a kindergarten may be estimated more if assuming that everyone is always in the room. The absolute humidity of the classroom without the humidifier was less than 5.8 g/kg' which was proposed that infection of influenza spread easily. It was thought that this main factor is caused by intrusion of dry outdoor air by window opening ventilation. Therefore it is desirable to raise the absolute humidity in the classroom of kindergarten on taking outdoor environment and the states of ventilation into consideration.