This paper aims to carry out measurements of indoor air temperature, relative humidity and carbon dioxide (CO2) concentrations as well as to determine CO2 production by students and teacher during various physical activities. Two classrooms of Technical University of Kosice were selected for the research. Results of objective measurements confirmed strong correlation between CO2 concentration occupancy for all measurements. Recommended value for indoor CO2 level according to Pettenkofer (1,000 ppm) was exceeding in 60.9%. Results of this study showed the insufficient ventilation intensity in classrooms as well as obvious rise of CO2 concentration during the exams. The highest increase of CO2 was recorded during harder physical activity (run on the spot, squats, right and left side lunges, and rotating of the hips). Regarding CO2 production by respondents it can be see that it is visibly increased with increasing physical activity.
Keywords: Carbon dioxide (CO2) production; Educational building; indoor environment; physical activity.