A dynamic air supply device used to produce simulated natural wind in an indoor environment

Natural ventilation is the most pleasant and suitable ventilation mode. Many researchers have claimed that they have produced simulated natural wind (SNW) using artificial devices. However, the characteristics of these kinds of SNW have been shown, through spectral analysis, to be clearly different from true natural wind (TNW). In this study, a dynamic air supply device based on direct-current (DC) motor control was designed to produce SNW, and the spectral characteristics of the airflow produced by this device were very close to those of TNW. To verify the application potential of this SNW, an experiment on thermal sensation and thermal comfort with regard to the SNW was conducted in both a climate chamber and a real office. Twenty-one subjects were exposed to five conditions: a constant neutral environment at 26 °C; a warm environment at 28 and 30 °C with constant mechanical wind (CMW), and a warm environment at 28 and 30 °C with SNW. In addition, twelve subjects used the device during work in a real office. The data of their thermal sensations was analyzed. The results suggested that the SNW was more effective in improving thermal comfort than the CMW in the warm environments. It was demonstrated that using SNW in a warm environment could result in almost the same thermal comfort as in a constant neutral environment.