Search Results (60)

Urban residential design influences local microclimates and human thermal comfort. This study combines empirical microclimate data with remotely sensed data on tree canopy cover, housing lot size, surface permeability, and roof colour to examine thermal differences between three newly built and three established residential suburbs in Western Sydney, Australia. Established areas featured larger housing lots and mature street trees, while newly developed suburbs had smaller lots and limited vegetation cover. Microclimate data were collected during summer 2021 under both heatwave and non-heatwave conditions in full sun, measuring air temperature, relative humidity, wind speed, and wet-bulb globe temperature (WBGT) as an index of heat stress. Daily maximum air temperatures reached 42.7 °C in new suburbs, compared to 39.3 °C in established ones (p < 0.001). WBGT levels during heatwaves were in the “extreme caution” category in new suburbs, while remaining in the “caution” range in established ones. These findings highlight the benefits of larger green spaces, permeable surfaces, and lighter roof colours in the context of urban heat exposure. Maintaining mature trees and avoiding dark roofs can significantly reduce summer heat and improve outdoor thermal comfort across a range of conditions. Results of this work can inform bottom-up approaches to climate-responsive urban design where informed homeowners can influence development outcomes. Full article

This study aims to (1) analyze thermal comfort at outdoor sport events held outside of fixed venues or locations; (2) establish a method for evaluating environmental thermal comfort for large-scale, long-term outdoor activities; and (3) provide suggestions for the arrangement of shifts in routes and participants for heat warning and mitigation. Taiwan ReAnalysis Downscaling (TReAD) data, Sky View Factors (SVFs), GSV2SVF tool, and RayMan Pro were applied to analyze and evaluate thermal comfort at the 2021 Torch Relay Round the Island, Taiwan. In this study, modified Physiologically Equivalent Temperature (mPET), Wet Bulb Globe Temperature (WBGT), and Universal Thermal Climate Index (UTCI) were estimated and selected as thermal indicators for the purpose of obtaining a more comprehensive perspective. We also define and present thermal performance with a simple traffic light symbol (green: comfortable/yellow: warm/red: hot) and try to go beyond the concept of heat and visualize it in an easy-to-understand way. Full article

As global mineral resources at shallow depths continue to deplete, thermal hazards have emerged as a critical challenge in deep mining operations. Conventional localized cooling systems suffer from a fundamental inefficiency where their cooling capacity is rapidly dissipated by the main ventilation airstream. This study introduces the innovative concept of a “microclimatic circulation zone” implemented through a convection–radiation cooling system. The design incorporates a synergistic arrangement of dual fans and flow-guiding baffles that creates a semi-enclosed air circulation field surrounding the modular convection–radiation cooling apparatus, effectively preventing cooling capacity loss to the primary ventilation flow. The research develops comprehensive theoretical models characterizing both internal and external heat transfer mechanisms of the modular convection–radiation cooling system. Using Fluent computational fluid dynamics software, we constructed an integrated heat–moisture–flow coupled numerical model that identified optimal operating parameters: refrigerant velocity of 0.2 m/s, inlet airflow velocity of 0.45 m/s, and outlet aperture height of 70 mm. Performance evaluation conducted at a mining operation in Yunnan Province utilized the Wet Bulb Globe Temperature (WBGT) index as the assessment criterion. Results demonstrate that the enhanced microclimatic circulation system exhibits superior cooling retention capabilities, with a 19.83% increase in refrigeration power and merely 3% cooling capacity dissipation at a 7 m distance, compared to 19.23% in the conventional system. Thermal field analysis confirms that the improved configuration successfully establishes a stable microclimatic circulation zone with significantly more concentrated low-temperature regions. This effectively addresses the principal limitation of conventional systems where conditioned air is readily dispersed by the main ventilation current. The approach presented offers a novel technological pathway for localized thermal environment management in deep mining operations affected by heat stress conditions. Full article

The effect of weather on the welfare of cattle grazing rangelands has received little study. The objective of this case study was to evaluate the effectiveness of a commercial rumen temperature bolus in monitoring changes in cattle body temperature and behavior during the summer on Arizona rangelands. Ten 2-year-old Corriente heifers were monitored by using SmaXtec Classic Boluses from 1 June to 29 August 2023. The bolus and weather data were averaged and analyzed on 3 and 24 h time scales. The bolus outputs included an activity index, a water intake index, the reticular temperature (RT) and the adjusted reticular temperature (ART, adjusted for drinking events). Weather metrics included the wet bulb globe temperature (WBGT), relative humidity (RH), ambient temperature (AT), wind speed, solar load and temperature–humidity index (THI). Weather variables were independently evaluated as a fixed continuous effect with linear, quadratic and cubic functions. The relative humidity and WBGT were better predictors of bolus metrics than other weather variables. Using 24 h data, the ART initially decreased by 0.4 °C as the WBGT increased from 2 °C to 15 °C, but the ART increased by over 0.15 °C with increasing WBGTs up to 24 °C. As the relative humidity increased, a proprietary bolus activity index initially increased with increasing RH to 45%, remained relatively constant until 65% RH and then increased at more humid levels. A proprietary water intake index decreased with increasing RH. Commercial rumen boluses have the potential to monitor body temperature and identify periods when cattle behavior may be affected by hot weather. Full article

Environmental temperature (T_e) is a main atmospheric parameter that may affect the physical and physiological demands of outdoor sports. Thus, this study aimed to examine the relationship of T_e with the physical and physiological demands of beach soccer match-play. Physical and physiological demands were collected from 60 male players during Portuguese elite beach soccer championship matches using a 10 Hz wearable global positioning system, heart rate, and the rate of perceived exertion (RPE). A bilateral counter-movement jump (CMJ) test assessed lower limb power performance before and immediately after the match. Fluid loss was determined by body mass weighing before and after the end of the match. T_e and wet-bulb globe temperature (WBGT) parameters were continuously recorded. The matches occurred across T_e ranging from ~20.0 °C to 43.0 °C. Physical demands, CMJ height, peak heart rate (HR_peak), mean heart rate (HR_mean), and RPE were not correlated with T_e. However, a significant correlation was found between fluid loss and T_e (r [95% CIs] = 0.67 [0.43–0.75]; p < 0.001). Beach soccer players maintained physical performance independent of T_e. The specific characteristics of the sport may have promoted adequate thermoregulatory adaptations, helping maintain the players’ physical performance, particularly in matches played under high T_e conditions. Elite beach soccer players maintained their physical performance independently of T_e and despite experiencing dehydration (a body mass decrease of more than 2%) when the T_e exceeded 35 °C. Full article

Zoos play dual roles in wildlife conservation and in providing recreational experiences for visitors in urban green spaces. However, the impacts of thermal environments on both visitor comfort and captive animal welfare remain unexplored, which is an important aspect to address for improving overall zoo management. This study investigated thermal conditions at Jinan Zoo, China, over 20 summer days. Questionnaires were used to collect visitor thermal comfort and viewing satisfaction, while the thermal mitigation behaviors of 70 blue peafowls were recorded under various thermal conditions on-site. The findings showed that the wet-bulb globe temperature (WBGT) neutral range for visitors was 20.1–24.4 °C, with a significant drop in visitor numbers when WBGT exceeded 35.5 °C. Visitors with higher animal viewing satisfaction (aVSV) scores were more heat tolerant. The blue peafowls reduced their activity levels and displayed feather-spreading and gular flutter at WBGT levels of 26.4–30.4 °C, especially during peak visitor hours. Our study also showed that visitor thermal sensation was most affected by radiation, whereas blue peafowl heat stress was likely influenced by air temperature, followed by humidity and radiation. These findings offer practical insights for designing zoo enclosures and visitor areas to improve comfort and animal welfare in hot weather. Full article

The recent rise in temperatures in urban areas has raised concerns about various health problems, such as heat-related illnesses. This study quantified the number of individuals exposed to outdoor heat during the daytime in the summertime waterfront area of Tokyo. Conventional meteorological observation and administrative data are insufficient for high-resolution analyses of people flow and heat conditions in urban environments. Therefore, this study introduced a new methodology combining urban computational fluid dynamics (CFD) and mobile phone global positioning system (GPS) data. A numerical simulation was performed to estimate the wet-bulb globe temperature (WBGT) by analyzing fluid dynamics and radiation models. The WBGT in parks was determined to be approximately 27 °C, while the on-road temperature exceeded 29 °C. Simultaneously, pedestrian density was assessed by collecting high-resolution mobile phone GPS data, revealing that pedestrians concentrated near stations, office areas, and shopping districts within a 5 km × 5 km area. Furthermore, a review of heat stroke cases (2010–2020) indicated that combining heat and people flow yielded stronger correlations with the number of heat stroke cases than considering heat alone. Finally, a new heat risk index was established, integrating heat, people flow, and aging rate, which more accurately predicted the heat stroke cases. Full article

As people spend the majority of their time indoors, maintaining a comfortable and suitable thermal environment within buildings is essential for improving quality of life. Previous studies in Japan have investigated the wet-bulb globe temperature (WBGT) in indoor environments; however, studies primarily focused on residential buildings are lacking. Therefore, a field survey of 17 Japanese dwellings was carried out during the summer, for which a total of 1166 thermal sensation votes (TSVs) were collected from 23 respondents. The results show that the average indoor air temperature is 26.4 °C, which is 1.6 °C lower than the recommendation for summer temperature by the Japanese government. The variation in globe temperature and WBGT indicates that there are significant differences in cooling usage behavior, with a strong correlation between WBGT and indoor globe temperature. The acceptable indoor globe temperature exhibits a wider range in free-running (FR) mode than in cooling (CL) mode. The mean comfort temperature was 26.9 °C in FR mode, while it was 27.0 °C in CL mode. These findings indicate that the occupants felt comfortable at the high indoor temperature, suggesting there is a possibility to reduce the energy used for cooling. Full article

Heat stress on workers wearing PPE (Personal protective equipment) in hot outdoor environments is of rising concern, especially in cases when rest breaks and clothing changes are impractical. Mist fan evaporative cooling could provide low-energy continuous cooling, even during work activity. The cooling effect of a misting fan was compared to that of a fan alone, as well as natural convection. A thermal mannequin with heat flux sensors at eight body locations was exposed to an outdoor misting fan while being clothed in typical work clothes and PPE. Work clothes were dry or saturated with water to simulate sweat. The distance from the misting fan ranged from 4 m (wetting common) to 7 m (wetting unlikely). On average, the misting fan had a cooling effect of 0.31 met (18.3 W/m²) higher than natural convection when PPE is worn with wet work clothes, and 0.35 met (20.3 W/m²) higher than when PPE is worn with dry work clothes. This equates to reducing the thermal metabolic load from light industrial work to walking about in office work, or from standing to reclining. Under the ISO 7243 international standard for workers in hot environments, this would increase the acceptable WBGT (wet bulb globe temperature) by over 0.6 °C. Full article

With the aging of China’s population and the liberalization of the birth policy, the country’s social population structure has changed, and the public activity spaces of residential areas are expected to meet the new needs created by such change. According to the existing literature, the most common population group in the public activity spaces in China’s current residential areas consists of the elderly with young children. However, how to evaluate the suitability of these spaces from the perspective of sunshine and thermal environments remains unclear. To fill this research gap, this article takes Xi’an as a case to explore the construction of an evaluation index system for sunshine and thermal environment suitability in the public activity spaces of residential areas for the elderly with young children. Firstly, based on field research and literature review, four initial indices were established, including sunshine demand hours, ultraviolet intensity, the universal thermal climate index (UTCI), and the wet bulb globe temperature index (WBGT). Secondly, on the basis of field research and expert interviews, these indices were revised and finalized, mainly with regard to the sunshine and thermal environment suitability for the elderly with young children in the urban residential area, so as to make the indices more in line with the actual research problems. Thirdly, a scoring method for each of the finalized indexes was proposed, resulting in a comprehensive evaluation index system. Finally, the suitability and operability of the constructed index system were validated through practical application in a sample residential area. The results show that, based on some known indices, the evaluation index system of the sunshine and thermal environment suitability of public activity space for the elderly with young children can be established. Its application is potentially helpful in making the public activity space environment in existing residential areas in China more adaptable to the needs of the elderly with young children. Full article

In the post-pandemic context, data-driven design interventions that can endow architectural spaces with mixed-use and open characteristics that are adaptable and environmentally resilient are increasingly important. Ubiquitous semi-public architecture, such as hotel buildings, plays a crucial role in public health emergencies. Many hotels adopt mixed-use and open room spatial layouts, integrating diverse daily functions into a single tiny space, fostering flexible utilization and micro-scale space sharing; however, these also introduce potential health risks. This study offers a comprehensive evaluation of the indoor environmental quality (IEQ) of a hotel room space and discusses feasible intervention strategies for healthier renovation and rehabilitation. Taking a hotel in Shenzhen as a case, a multi-domain environmental assessment was conducted during the COVID-19 quarantine period in the summer of 2022. The study examines the health risks inherent in the hotel’s guest room and the varying patterns of IEQ factors across the hotel’s domains, including volatile organic compound concentrations, physical environmental parameters, and heat stress indices. The results illustrate diverse change trends in the chemical, physical, and heat stress factors present in the tested quarantined hotel room space throughout a typical summer day. Although most of the examined environmental factors meet local and global standards, some problems draw attention. In particular, the PM2.5 concentration was generally observed to be above the World Health Organization (WHO) air quality guideline (AQG) standards, and the interior lighting did not meet required standards most of the time. Moreover, correlation and multiple regression analyses uncover significant influence by physical environmental conditions on the concentrations of chemical pollutants in the hotel room. The study preliminarily identifies that higher relative humidity could lead to a lower concentration of CO₂ while a higher PM2.5 concentration. Wet bulb globe temperature (WBGT) was observed to positively affect CO₂ concentration. Further, the results suggest that even with relatively rigorous initial adjustment and re-renovation, multi-domain environmental quality in air-conditioned quarantine hotel rooms should be monitored and ameliorated from time to time. Overall, this study offers a scientific foundation for healthier upgrades of existing hotel buildings as well as provides insights into achieving environmental resilience in newly constructed hotel buildings for the post-pandemic era. Full article

Adaptation measures to urban heat islands are classified into the following three categories: measures to reduce solar radiation incident on the human body, measures to control and cool ground and wall surface temperature, and measures to control and cool the air and human body temperature. Case studies are conducted to evaluate the effects of the implementation of a cool water circulation sunshade and to examine the adverse effects of cool pavements on the human thermal environment, in addition to the effects of mist sprays on the human body. The effect of the sunshade, watering road, and mist spray, which are typical adaptation measures to urban heat islands, on the human thermal environment was estimated using Wet Bulb Globe Temperature (WBGT) as an indicator for heat stroke prevention and Standard New Effective Temperature (SET*) as an indicator for thermal comfort assessment. The effect of solar radiation shielding on improving the human thermal environment was the most significant, with a large decrease in the amount of solar radiation absorbed by the human body, resulting in a large decrease in SET* and WBGT of 2.7 °C and 1.0 °C, respectively, on fine summer days. Full article

This study focuses on improving human thermal comfort in a high-temperature outdoor environment using vests with a radiative cooling coating. The effects of coating thickness on the radiative cooling performance were first evaluated, and an optimal thickness of 160 μm was achieved. Then, six subjects were recruited to evaluate the thermal comfort in two scenarios: wearing the vest with radiative cooling coatings, and wearing the standard vest. Compared with the standard vest, the coated vest decreases the maximum temperature at the vest inner surface and the outer surface by 5.54 °C and 4.37 °C, respectively. The results show that thermal comfort is improved by wearing radiative cooling vests. With an increase of wet bulb globe temperature (WBGT), the improving effects tend to decline. A significant improvement in human thermal comfort is observed at a WBGT of 26 °C. Specifically, the percentage of thermal sensation vote (TSV) wearing the cooling vest in the range of 0 to 1 increases from 29.2% to 66.7% compared with that of the untreated vest. At the same time, the average value of thermal comfort vote (TCV) increases from −0.5 to 0.2. Full article

With the frequent occurrence of extreme weather in various parts of the world, people have begun to reflect on the scientific rationality of the means of global climate change governance. How to effectively respond to the hazards caused by extreme weather remains a hot issue of concern to the international community. In this paper, taking the function of plant carbon sequestration and oxygen release, which can regulate human thermal comfort as an entry point, we use virtual reality (VR) to construct a digital scene and invite subjects to conduct behavioral experiments in order to assess human thermal comfort. The experimental results indicate that participants’ subjective evaluations of virtual and real environments are consistent with changes in heart rate variability (HRV), validating the reliability of using virtual environments to study thermal perception. The study also found a significant correlation between HRV and the wet bulb globe temperature (WBGT) index, which both measure human thermal comfort. This suggests that when the WBGT changes due to microclimate variations, HRV changes accordingly. The negative correlation between plant carbon sequestration oxygen release capacity and HRV further supports this view. It also indicates that human thermal comfort can provide feedback on microclimate change trends, and that accurate monitoring of the microclimate is more conducive to assessing the progress of climate warming. This study demonstrates the association between human comfort and microclimate change, discusses the validity of human thermal comfort metrics in climate monitoring, and provides new perspectives for solving the global climate crisis. Full article

Hot working environment not only affects work efficiency, but also poses a potential threat to the physical and mental health of staff. The current common method for dealing with high temperatures is spray-only or ventilation-only. To investigate the impact of different spray and ventilation modes on indoor high-temperature environments, this study examined their effects on indoor environmental parameters, average skin temperature, and psychological indicators. By establishing an experimental platform for high-temperature thermal environments, a spray ventilation cooling system was implemented, and its cooling efficacy in the indoor thermal environment was analyzed. The environmental classification of the high-temperature working environment under experimental conditions is provided based on the experimental data. A comparison and analysis of environmental parameters and physiological and psychological indicators between moderate and high-temperature environments were conducted. The combination of spray and ventilation modes resulted in a 5.3 °C reduction in air temperature, a 24.1% increase in average relative humidity, and a 3.3 °C reduction in average Wet-bulb Globe Temperature (WBGT). The cooling effect was increased by 2.3 °C and the average relative humidity was increased by 10.8% compared to spray-only and ventilation-only modes. In spray and ventilation mode, when the spray volume is increased by 15 mL/min, the air temperature is reduced by 8.2 °C, the average relative humidity is increased by 31.9%, and the average WBGT is reduced by 5.1 °C. This study has guiding significance for finding a reasonable cooling scheme to cope with indoor high-temperature environments. Full article