Indoor Air Quality and Thermal Environment of Elementary Schools in Winter

This study aims at investigating the actual conditions of indoor environment in schools in order toobtain fundamental information for proper ventilation design of buildings. Indoor environment of twonew elementary schools in Tohoku district of Japan was investigated for a week in the winter 2005.Temperature and humidity, concentrations of Carbon Dioxide (CO2), ventilation airflow rates,concentrations of chemical substances, and the opening condition of the windows and doors weremeasured in the three classrooms of each school. The CO2 concentration was higher than 1500 ppm in many hours due to the lack of ventilation. Exhaust airflow rate at the outlet was only 10 percent of the design values. This is due to no maintenance of the ventilation systems and no cleaning of filters.It was observed that meshes for protecting insect of the outlet of exhaust ducts. The CO2 concentration was higher than 1500 ppm in some classrooms because exhaust airflow rate at outletwas very low. In winter it is difficult to open the windows because outdoor temperature was very low.Maintenance of ventilation system is very important in order to increase exhaust airflow rate at outletand improve indoor air quality.