Evaluation of mist-spraying environment on thermal sensations, thermal environment, and skin temperature under different operation modes

Abstract

This study aimed to evaluate an outdoor mist-spraying environment and its effect on thermal sensations, thermal environment, and skin temperature. A mist-spraying system with four modes was operated with various amounts of water spraying, both in the absence and presence of an air blowing control. Thermal sensations were reported by subjects for each operation mode and then investigated using three scales: modified thermal sensation vote (mTSV), thermal sensation vote (TSV), and comfort sensation vote (CSV). Environmental factors were compared between the outdoor and mist-spraying environments, and skin temperatures were monitored throughout the experiment. The correlation between the thermal sensations and overall skin temperatures was analyzed. The results showed that the air temperature inside the mist-spraying environment decreased (−2.9 ± 1.2 °C) when the mist system was operated with a larger amount of spraying water and the air temperature decreased further (−3.6 ± 1.4 °C) with the addition of an air blowing fan. Survey results (n = 65) suggested that the mTSV changed from slightly hot to neutral, TSV changed from warm to neutral, and CSV changed from slightly uncomfortable to slightly comfort, respectively, due to the cooling effect of the mist-spraying system. The overall skin temperature decreased by approximately −0.53 °C (n = 65) from the baseline operation mode. Moreover, the overall skin temperature showed a higher correlation with the mTSV than with the TSV, and their correlation was higher in the mist-spraying environment compared with that in an outdoor environment.