Measurements of CO2 levels in Classroom & its effect on performance of students

Session 3 Paper 2, CIBSE ASHRAE Technical Symposium, Imperial College, London, UK
18th and 19th April 2012

This paper will describe the effects of high CO2 concentration on the thermal comfort and academic performance of students during winter and summer in a large occupied lecture room.

An experimental method including objective measurements of air quality monitoring and building physical measurements was used with subjective measurements combined with academic performance and thermal comfort questionnaire.

The results show average performances for a sixty percent attendance rate per class at approximately 48%-62%. The maximum daily average CO2 levels for the sample was 2,714 parts per million (ppm). This is much higher than the 1,500 ppm daily requirements. The condition of the lecture room during the summer period, based on a five point Predicted Mean Vote (PMV) scale of subjective responses of the students were found to be slightly hot, slightly humid, slightly stuffy, slightly bright and slightly noisy.

A computer model produced daily ventilation rates ranging from 0.25 – 0.93 litres per second per person. This is also much lower than the required minimum background ventilation rates of 3 litres per second per person.