RELATIONSHIPS BETWEEN INDOOR AND OUTDOOR AIR-QUALITY IN 4 NATURALLY VENTILATED OFFICES IN THE UNITED-KINGDOM

Three offices in central London and one at a rural location were chara cterized with respect to air quality. All four offices were naturally ventilated. The characterization was supplemented by using a mobile la boratory to monitor the outdoor air quality. Results indicate that ind oor pollutant concentrations may be up to 80% of the concentration out doors but can greatly exceed outdoor concentrations. Additionally, it has been shown that indoor pollutants usually follow outdoor pollutant trends at lower levels, with only a small time delay due to mixing an d dilution factors. The interaction between indoor and outdoor air is discussed with respect to ventilation characteristics and pollutant so urces. A comparison between actual and modelled carbon dioxide levels may provide a useful indicator of ventilation.