The influence of perceived control on outdoor thermal comfort: A case study in a hot summer and warm winter climate

Perceived control is a psychological state experienced by individuals in their environment and is considered a critical factor in adaptive thermal comfort models. A longitudinal study lasting two and a half years was conducted in Xiamen, China, to investigate the impact of perceived control on outdoor thermal comfort. The study, carried out in an outdoor living laboratory with 56 participants, explored conditions with and without perceived control. Subjective thermal perception and thermal environment parameters were collected. Differences in outdoor thermal comfort across summer, transition seasons, and winter between participants with and without perceived control were established, and conversion formulas for thermal sensation votes were obtained. The study results indicate that: (1) The neutral mPET of participants with perceived control were 26.4 °C, 24.9 °C, and 22.3 °C in summer, transition seasons, and winter respectively, while those without perceived control were 25.2 °C, 24.6 °C, and 22.8 °C respectively. (2) Participants without perceived control tend to prefer different thermal environment (either cooler or warmer). (3) Perceived control expanded the range of acceptable thermal environment for participants in all seasons. (4) Perceived control can reduce outdoor thermal sensitivity and make participants more likely to achieve a comfortable thermal experience, but the effect varies under different thermal conditions. (5) Regardless of perceived control, global radiation and air temperature are the most crucial environmental factors affecting thermal sensation, while the impact of clothing thermal resistance and duration of stay on thermal sensation is enhanced under conditions without perceived control.