Grams H, Hehl O, Dressman J
Bibliographic info:
Gesundheitswesen, 2003 Jul ; 65(7) , pp 447-456

Carbon dioxide concentration, indoor air temperature and relative air humidity are studied in 7 schools with natural ventilation systems, during 58 days on one year. The results show that the level of 1500 ppm of CO2 is exceeded in 39 days. A software programme was developed to calculate the CO2 concentration level according to the number of pupils and the ventilation rate.
Health problems may result from a too low ventilation rate.