ABSTRACT

Ventilation air is needed to sustain safe and comfortable conditions for the occupants. The quantity of outdoor air is related to human activity level and the need to

remove or dilute atmospheric pollutants. Occupational exposure limits (OEL) are stipulated by the Health and Safety Executive (HSE, 1990) based on an average for an 8 h working day, or a peak 10 min period. The carbon dioxide (C0 2) limit is 5000 parts per million (ppm) or 0.5%.