Concentration of carbon dioxide measured in university classrooms

Low concentration of carbon dioxide in the atmospheric air is considered to be a normal condition. Excessive concentration of CO2 in the air may have negative influence on human’s health. Permissible level of carbon dioxide concentration in didactic facilities as well as in all other closed spaces is 1000 ppm (WHO, 2000a), as devised by the WHO Regional Office for Europe. Two varieties of measurements were taken. 1. The level of CO2 concentration was examined in classrooms in which different types of ventilation systems are used. 2. The efficiency of the ventilation system was measured on the basis of the parameters of the inside air; particular attention was paid to the level of CO2 concentration.