Concentration variations of pollutants in a work week period of an office

Indoor air quality problems for a typical office space were investigated. Continuous monitoring of concentrations was carried out for CO2, CO, formaldehyde, and total hydrocarbons. It was found that the CO2 concentration was at times above 2000 ppm and that for CO above 14 ppm. In addition, concentration levels of formaldehyde and total hydrocarbon were found to peak at midnight and indicated non-human sources. Partial opening of windows resulted in CO2 concentration levels of 800 ppm or below. Ventilation rate measurements using trace gas decay method found that the air change rates were well below one air change per hour.