Main effects and interactions of multiple key factors related to thermal perception.

The real indoor environment involves the comprehensive interaction of multiple factors, and human subjective responses to different factors are influenced by various aspects such as physics, physiology, and psychology. The relative significance of various factors influencing different types of human subjective thermal perception, as well as the extent of their interactions, remains somewhat unclear. This investigation, leveraging the "Chinese Thermal Comfort Dataset," analyzed the integrated impact of basic thermal perception factors-temperature, humidity, air speed, as well as clothing insulation and metabolic rate-on subjective thermal perception. The findings underscored the definitive role of air temperature as the primary determinant of thermal sensation, with the impact of other factors generally remaining below 15 % of temperature. Nonetheless, the sensitivity of thermal sensation to temperature is significantly affected by other factors, demonstrating a significant interaction between temperature and different factors in influencing temperature sensation. Additionally, it was observed that significant differences (p < 0.001) in thermal comfort levels existed even at the same thermal sensation. For instance, in the state of thermal neutrality, occupants with relatively higher clothing insulation reported higher thermal comfort level (d = 0.40, p < 0.001) during the cooling season but lower thermal comfort level (d = 0.54, P < 0.001) during the heating season. Consequently, it can be deduced that when comprehensively considering the impact of multiple factors, evaluating the environment solely based on thermal sensation or thermal neutrality may prove insufficient.

The Chinese thermal comfort dataset.

Heating and cooling in buildings accounts for over 20% of total energy consumption in China. Therefore, it is essential to understand the thermal requirements of building occupants when establishing building energy codes that would save energy while maintaining occupants' thermal comfort. This paper introduces the Chinese thermal comfort dataset, established by seven participating institutions under the leadership of Xi'an University of Architecture and Technology. The dataset comprises 41,977 sets of data collected from 49 cities across five climate zones in China over the past two decades. The raw data underwent careful quality control procedure, including systematic organization, to ensure its reliability. Each dataset contains environmental parameters, occupants' subjective responses, building information, and personal information. The dataset has been instrumental in the development of indoor thermal environment evaluation standards and energy codes in China. It can also have broader applications, such as contributing to the international thermal comfort dataset, modeling thermal comfort and adaptive behaviors, investigating regional differences in indoor thermal conditions, and examining occupants' thermal comfort responses.

Temporal and spatial heterogeneity of indoor and outdoor temperatures and their relationship with thermal sensation from a global perspective.

People spend most of their time indoors. However, indoor temperature and individual thermal exposure are generally not considered in epidemiological studies of temperature and health. Based on the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) RP-884 Database, the ASHRAE Global Thermal Comfort Database II and the Chinese Thermal Comfort Database, this study first explored the relationship between outdoor temperature, indoor temperature and thermal sensation from a global perspective. Moreover, the potential influence of spatiotemporal heterogeneity on health studies was explored. A breakpoint was found at approximately 11.5 °C in the segmented regression of indoor and outdoor temperature, and the slope of the curve was greater when outdoor temperature was above the breakpoint (n = 67,896). Based on multi-group propensity score matching (PSM) and generalizedadditivemodels (GAM), spatiotemporal heterogeneity was found in the relationship between indoor and outdoor temperatures after adjusting for building type and year. Furthermore, the relationship between indoor temperature and thermal sensation was influenced by the outdoor temperature. This study highlights the importance of considering indoor temperature or individual thermal exposure in temperature-related health studies.

Locating leakage in pipelines based on the adjoint equation of inversion modeling.

This paper presents an adjoint method for locating potential leakage in a single-phase fluid pipeline based on the analytic solution of inversion modeling. By studying the mechanism of pipeline leakage pressure, the adjoint equation based on the governing equation of transient flow is established in the single-liquid phase aspect using inverse adjoint theory and sensitivity analysis method. The inverse transient adjoint equation is primarily derived from the single linear fluid pipeline in the semi-infinite domain. The Laplace method is then used to obtain an analytical solution that determines the location of pipeline leakage. The experimental results indicate that the analytic solution can quickly and accurately judge the leakage location of the pipeline. Furthermore, it presents a new approach to engineering applications, such as gas-liquid two-phase flow complex pipe networks, etc.