PRODUCTIVITY IS AFFECTED BY THE AIR QUALITY IN OFFICES

The results of three independent studies involving 90 subjects, and using similar procedures and blind exposures have shown that increasing air quality (by decreasing the pollution load or by increasing the ventilation rate, with otherwise constant indoor climate conditions) can improve the performance of simulated office work (text typing, addition and proof-reading). An analysis of the combined data from these studies is presented to establish the relationship between air quality and performance in offices. It confirms that good air quality improves the performance of text typing (P=0.0002), and a similar tendency is seen for addition (P=0.056) and proof-reading (P=0.087). A positive correlation between the air quality, as it is perceived by occupants, and the performance of typing (R 2 =0.82, P=0.005), addition (R 2 =0.52, P=0.07) and proof-reading (R 2 =0.70, P=0.08) indicates that performance will increase on average by 1.5% when the proportion dissatisfied with the air quality is decreased by 10% in the range of air quality levels causing 25-70% to be dissatisfied. The results imply that doubling the outdoor air supply rate at constant pollution load, or a two-fold decrease of pollution load at constant ventilation rate, can increase overall performance by 1.9%. The present results document the economic benefits of providing good indoor air quality and indicate that providing indoor air of a higher quality than the minimum prescribed by the present ventilation standards will increase productivity.