Influence of sampling point distributions on the accuracy of indoor air environment measurements

Air distributions, such as the distributions of airflow, air temperature and contaminant concentrations, are very important to occupants' health and comfort in enclosed spaces. In order to obtain the air distribution, in-situ measurements are often conducted with point sensors such as anemometers, thermocouples, and tracer-gas samplers. The sensor sampling locations are highly related to the measuring accuracy, time invested, and labour costs, when the data is interpolated to field distributions. This investigation proposed a gradient-based sampling method and evaluated quantitatively the sampling locations and measuring accuracy by using the distributions of air velocity and air temperature in an office. The data was interpolated into field distributions by Kriging method. The errors were analyzed in the field distributions obtained with the gradient-based and grid sampling methods through Kriging interpolation. The results show that the gradient-based method was more accurate than the grid method. This investigation also studied the relationship between sampling size and measuring errors.