Jiang He

It has been proven that the thermal sensation and comfort differ among people living in different climate zones. However, related analyses are often limited to typical climate zones, lacking studies focused on populations in regions like Southern China (Guangxi) with hot-humid and low-windy climates. To address this research gap, this study selected dozens of local elderly and young adults as subjects, conducting questionnaire surveys and on-site measurements in a climate room. The investigation results indicate a significant difference in the thermal comfort between the elderly and young in the study region (Southeast Guangxi). The elderly exhibit more heat-tolerant characteristics in both physiological responses (skin temperature, heart rate) and psychological responses (mean thermal sensation vote, thermoneutral temperature, etc.), and have a wider comfort temperature range. The thermoneutral temperature of older people is 27.0°C, while that of young people is 26.6°C. It was also found that the thermal comfort model (PMV-PPD) is inapplicable to the elderly in this region. The findings obtained in this study can provide a reference for analyzing thermal comfort differences between the elderly and young in hot-humid and low-windy regions. It also offers important insights for developing thermal comfort models for the elderly and designing age-friendly air-conditioning systems.

There is still a lack of research on the evaluation of summer thermal comfort for the elderly. This study conducted a questionnaire survey and indoor thermal environment measurement in Nanning, China, with a hot‐humid and less‐windy climate. Six hundred elderly subjects were selected to answer the thermal sensation questionnaire in the naturally ventilated residential buildings during the summer. The analysis results of the collected data show that the neutral temperature for the local elderly is 28.0°C, and the range of operative temperature for 80% thermal acceptability is 26.4°C–29.5°C. An adaptive thermal comfort model was developed using the measured data, and its predicted thermal neutral temperature is 28.1°C, nearly equal to the measured value (28.0°C). The thermal neutral temperatures for the local male and female elderly are 27.7°C and 28.2°C, respectively, which reveals that there are gender differences in the thermal comfort. It was also found that the outdoor air temperature has a significant impact on the thermal neutral temperature, and the developed adaptive thermal comfort model can more accurately predict the indoor thermal comfort of the local elderly. The findings in this study can provide theoretical support and supporting data for the indoor thermal environment design of new old‐age facilities and aging‐adapted renovation of existing buildings in hot and humid climates.

The cooling performance of the energy-saving water spray window cooling system under summer conditions in Nanning city in southern China, is experimentally examined in this study. By constructing two identical test rooms for comparison, in the experiment we analyzed the effects of water temperature (22 °C, 26 °C, 30 °C), spray frequency (8, 10, 12, 15 min intervals), glass structure (single-layer, double-layer, triple-layer), air conditioning temperature (26 °C, 27 °C, 28 °C, 29 °C), and outer lamination thickness (30, 50, 100, 200 mm) on the cooling effect of windows, aiming to determine the optimal operating conditions. The experimental outcomes demonstrate that the appropriate operating mode for the water spray window system involves using the coldest water source (22 °C), with a spray interval of 8 min, a three-layer air cavity sprayed glass construction, an air cavity thickness set at 100 mm, and the best air conditioning temperature (26 °C). The study found that the water spray system can reduce the outer glass surface temperature of the window by 6 °C and the inner surface temperature by 2 °C. Moreover, the more glass layers and the thicker the lamination, the higher the energy saving rate; with a maximum energy saving rate of 35.19%. The water spray window has good adaptability and significant energy-saving effects in Southeast Asia. By scientifically selecting energy-saving glass types and fine-tuning operating modes, it is expected that efficient building energy conservation in hot climates can be achieved.

Owing to the unique climate of Mongolia, the heat supply of residential buildings is a pressing social and economic problem. In Mongolia, the heat loss indicators for numerous residential buildings still exceed the standard. There is an urgent need to update and improve the architectural structure of residential buildings for energy saving. Few studies focused on energy consumption and the indoor environment in residential buildings in Mongolia. To provide effective and practical energy-saving measures, we conducted field surveys and measurements to clarify the energy consumption and indoor environment in residential buildings. A questionnaire was used to collect data from 100 households in Ulaanbaatar (the capital city of Mongolia), and five representative buildings were selected as the study objects to investigate the indoor thermal environment. The measurement result shows that the average indoor air temperature and relative humidity in the living rooms and bedrooms were 25.4 °C and 26.3%, 24.0 °C and 33.2%, respectively. The indoor air temperature was higher, and the air humidity was lower than the national standards. The average ventilation rate lies between a maximum of 71 m³/h and a minimum of 46 m³/h. The breakdown of the total heat loss shows that the ventilation heat loss of two objects is high. The total heat loss for the study objects was between 1.202–1.694 W/(m²K). The analysis result reveals that there exist great potential and effective measures to save heating energy.

Pedestrian space is an important place for people’s outdoor activities. Its thermal environment affects pedestrian walking experience, route selection and physical health. This study presents a 3D thermography-based method to analyze and evaluate the spatial distribution of thermal comfort. The proposed 3D thermal image was generated using 3D city models captured by an unmanned aerial vehicle (UAV) and thermal images gathered by an infrared camera. It can visualize construction elements, but also simply output surface temperatures at selected points. This paper described the process of using 3D thermal images to analyze the built environment, and selected two pedestrian spaces as case study objects. Their thermal images and mean radiant temperatures (MRT) were obtained from field measurement data collected by a drone and infrared camera. The following findings were obtained: (a) the MRT difference in the pedestrian space between sunlit and shaded areas was more than 3 °C; (b) the MRT values at the measurement points near vegetation were lower; (c) when the ratio of street height to width (H/W) was larger, the MRT values at all measurement points varied slightly. These findings can be used for the designers to evaluate and improve the thermal environment in pedestrian space.