classroom

PCM (phase change materials) is an innovative technology and an effective method for improving the thermal mass of buildings owing to it possesses the property of large thermal capacity within a limited temperature range, which is similar to an isothermal energy tank. However, most of the previous studies focused on the combination of PCM and walls that the utilization potential of rooftop is lack of concern though there is a significant amount of heat gains from rooftop.

Air quality in a classroom is very important. According to a study by Wargocki et al (2012) a shortage of ventilation in the classroom reduces the ability of students to concentrate and causes an increase in the number of errors during the elaboration of tasks. The aim of this study was to contribute to the optimization of acquisition and operating costs of HVAC equipment and to ensure hygienic requirements of air quality in the indoor environment for classrooms.

Most traditional elementary school classrooms here do not have air-conditioners and it often feel stuffy in classrooms located in the top floors. In addition, traditional classrooms widely have noise problem  so do the open educational classrooms. If the windows and doors are closed to reduce noise, it will result in the phenomenon of stuffiness, which largely prevents the external air entering the room.

This paper discusses on the indoor thermal environment controlled by the air-conditioners and the ceiling fans under the heating condition. An experiment which measured the temperature and the indoor wind velocity was conducted in the classroom with the ceiling fans. The preset temperature was 24oC, and the airflow direction of the ceiling fans was upward. The rotational speed of the ceiling fans were changed (90-300rpm). Questionnaires to the occupants were also conducted to figure out the problem when the ceiling fans were used in the classroom.

The winter thermal environment and indoor air quality in classrooms has been reported to be very poor in Japan. In this study, an air-conditioned, mechanically ventilated classroom was surveyed. Air temperature, globe temperature and the concentration of CO2 were monitored before, during and after the three-hour occupancy by 35 adults. Airtightness and airflow rates of the ventilation system were also measured.

To clarify the indoor climate in Japanese college classrooms, an air-conditioned, mechanically ventilated classroom of a university was surveyed. Temperatures, humidity and carbon dioxide (CO2) concentration in winter and summer were measured before, during and after lessons. The airtightness of the room and the airflow rate of the ventilation system were also measured. In winter, at an outdoor air temperature around 0 ºC and with the thermostat temperature of the air conditioners set to 30 ºC, the vertical difference in room air temperature exceeded 10 ºC.

19 university students were asked about their thermal comfort while attending ordinary lessons in a displacement ventilated test room of typical classroom size. Two different ceiling heights were tested. Both the general temperature level and the strength of the vertical temperature stratification in the room increased continuously during the lessons due to the presence of the students, however slower with the higher ceiling.