Improving thermal comfort using personalized local conditioning: A large-scale retrospective questionnaire survey conducted during a heatwave in China

The increasingly frequent heatwaves caused by global warming indicate that more energy consumption is required to maintain individuals' thermal comfort and health. Understanding how to utilize local conditioning for optimizing conditioning devices and creating a comfortable environment is crucial. Due to variations in individuals' adaptability to their surroundings, people from different climatic zones exhibit different needs for environmental conditioning. Current research findings in built environments have not adequately explained how individuals in various climatic zones use local conditioning to meet these diverse thermal needs. Therefore, it is highly important to conduct quantitative research on individuals' willingness to use local conditioning and their preferences across different climatic zones. To address this issue, a retrospective survey of 2,247 participants across five climate zones in China was conducted over a two-month period. The results revealed that many participants chose to use local conditioning to further improve thermal comfort, even if they initially felt comfortable. Participants from the severe cold and cold zones preferred water-cooled fans and floor fans, whereas floor fans were the preferred choice in other zones. Price and convenience were the main factors considered when selecting local conditioning devices (average composite score > 7). Differences in the methods, duration, parameter settings, placement of local conditioning, and regulated body parts varied among participants from the five climate zones. These results aid in improving our understanding of thermal comfort and health in high-temperature environments during summer.