Towards Healthy Levels of Carbon Dioxide in Schools of the National Oil Company of Abu Dhabi

In their annual indoor air quality assessment for ADNOC Schools, the Abu Dhabi Education Council has reported hazardous levels (∼3000 ppm) of carbon dioxide in fifteen classrooms. Exposure of 5,090 students attending the school for ∼eight hours (typical school day) to such high levels of carbon dioxide would induce adverse health conditions like headaches, drowsiness, and lack of concentration on the short term and serious diseases like asthma and sick building syndrome on the long term. The Health, Safety, and Environment committee of the school has identified clogged air intake vents and dirty AC filters as the main cause of the high carbon dioxide concentrations reported. The outdoor (ambient) carbon dioxide level is measured and has an eight-hour average value of 419 ppm. After cleaning thoroughly, the indoor levels of carbon dioxide, temperature, and relative humidity were monitored simultaneously in each classroom and have average values of ∼1117 ppm, ∼24°C, and ∼37%, respectively. In addition, the average indoor-to-outdoor ratio of carbon dioxide has been improved from 3000 / 419 ≈ 7.2 before cleaning the AC filters to an average ratio of ( 1,117 / 419 ≈ 2.7 ) after cleaning. Thus, ventilation rates in the classrooms monitored in this project are adequate and the corrective actions taken were effective.