The Effects of Constant Mechanical Wind, Sinusoidal Wind, and Simulated Natural Wind on Thermal Comfort in a Slightly Hot Environment

In high-temperature environments, using airflow systems has been demonstrated to be an effective method of regulating thermal sensation and enhancing thermal comfort. Given the importance of optimizing airflow selection strategies, the impact of different airflow forms on thermal comfort is a topic worthy of consideration. This study aimed to compare and analyze thermal comfort under three distinct airflow conditions: constant mechanical wind, sinusoidal wind and simulated natural wind. The experimental condition was set to a high temperature of 30 °C. The experimental results show that thermal sensation votes (TSV) are lower and thermal comfort votes (TCV) are higher in the simulated natural wind environment than in the other two environments. Statistical analysis of subjects’ environmental preferences showed that simulated natural wind was the most preferred option. When exposed to simulated natural wind, subjects reported a stronger sense of softness and relaxation than when exposed to constant mechanical wind or sinusoidal wind. Additionally, the level of calmness experienced under the simulated natural wind condition was found to be lower than that observed under the constant mechanical wind condition. Comparing TSV and TCV results over time reveals that thermal comfort is influenced not only by thermal sensation but also by the stimulation that different types of airflow variation exert on the human body. Concurrently, in airflow environments, thermal sensation exhibits a non-linear relationship with changes in skin temperature, and this relationship may be influenced by airflow stimulation. This study clarifies the mechanism by which different airflows affect thermal comfort differently in high-temperature environments. It thereby provides both experimental evidence and theoretical support for the airflow design of air-conditioning systems, with the goal of aligning such designs with human physiological perceptual characteristics.