Global reductions in manual agricultural work capacity due to climate change.

Manual outdoor work is essential in many agricultural systems. Climate change will make such work more stressful in many regions due to heat exposure. The physical work capacity metric (PWC) is a physiologically based approach that estimates an individual's work capacity relative to an environment without any heat stress. We computed PWC under recent past and potential future climate conditions. Daily values were computed from five earth system models for three emission scenarios (SSP1-2.6, SSP3-7.0, and SSP5-8.5) and three time periods: 1991-2010 (recent past), 2041-2060 (mid-century) and 2081-2100 (end-century). Average daily PWC values were aggregated for the entire year, the growing season, and the warmest 90-day period of the year. Under recent past climate conditions, the growing season PWC was below 0.86 (86% of full work capacity) on half the current global cropland. With end-century/SSP5-8.5 thermal conditions this value was reduced to 0.7, with most affected crop-growing regions in Southeast and South Asia, West and Central Africa, and northern South America. Average growing season PWC could falls below 0.4 in some important food production regions such as the Indo-Gangetic plains in Pakistan and India. End-century PWC reductions were substantially greater than mid-century reductions. This paper assesses two potential adaptions-reducing direct solar radiation impacts with shade or working at night and reducing the need for hard physical labor with increased mechanization. Removing the effect of direct solar radiation impacts improved PWC values by 0.05 to 0.10 in the hottest periods and regions. Adding mechanization to increase horsepower (HP) per hectare to levels similar to those in some higher income countries would require a 22% increase in global HP availability with Sub-Saharan Africa needing the most. There may be scope for shifting to less labor-intensive crops or those with labor peaks in cooler periods or shift work to early morning.

Morphological spatial clustering of high-density central areas and their coupling relationship with thermal environment--a case study of the wuyi road hatchback in changsha.

Intense urban development and high urban density cause the thermal environment in urban centers to deteriorate continuously, affecting the quality of the living environment. In this study, 707.49 hectares of land in the central area of Changsha were divided into 121 plots. 11 microclimate-related morphological indicators were comprehensively selected, and the K-means method was used for cluster analysis. Then, the relationship between morphological clusters and the thermal environment was explored by simulating the thermal environment of the study area with ENVI-met. First, five spatial types were found to characterize the area: high-level with high floor area ratio, low density, and low greenery; middle-level with high floor area ratio high density; medium-capacity with high density and small volume; low-level with low density and high greenery; and low floor area ratio, low density, and high greenery. Second, the building windward surface density, sky openness, building density, floor area ratio and green space rate affect the thermal environment. Third, Cluster3 had the highest average air temperature (Ta), followed by Cluster5, furthermore Clusters4, 1, and2 had relatively low Ta. The spatial vitality index and green space rate in Cluster1; the area-weighted building shape index, average building volume and sky openness in Cluster2; green space rate in Cluster3; indicators such as the floor area ratio and green space rate in Cluster4; indicators such as the impervious surface rate and green space rate in Cluster5 had greater influences on Ta. Fourthly, simply increasing the area of green space cannot maximize the cooling effect of green spaces. Instead, constructing an equalized greening network can better regulate the thermal environment. Fifthly, the results provide a scientific basis for the design and the regulation of urban centers.

Spatiotemporal variability in human thermal comfort perception in open-air spaces: application to the state of Minas Gerais, Brazil.

The objective of this study was to propose bioclimatic zoning to classify human thermal comfort and discomfort in the state of Minas Gerais, Brazil; both historical and future scenarios are considered. Thus, historical series (1961 to 2017) of the effective temperature index as a function of the wind (ETW) were obtained as a function of the monthly average values of the minimum, mean, and maximum dry-bulb air temperatures (tdb,min, tdb,mean, and tdb,max, respectively), in addition to the mean relative humidity ([Formula: see text], %) and mean wind speed ([Formula: see text], m s -1). The data were obtained from 34 weather stations and subjected to trend analysis by using the nonparametric Mann-Kendall test, thus enabling the simulation of future scenarios (for 2028 and 2038). Then, to define the thermal ranges of the bioclimatic zoning, maps of ETWmin, ETWmean, and ETWmax were created from geostatistical analysis. Overall, the results show warming trends for the upcoming years in Minas Gerais municipalities. All climatic seasons showed an increase in the frequency of new classifications in the upper adjacent classes, which indicates climate warming. Therefore, when considering future scenarios for the autumn and winter seasons, attention should be given to changes in predicted thermal sensation, especially in the Central Minas Gerais, Belo Horizonte Metropolitan, South/Southwest Minas, Campo das Vertentes, and Zona da Mata.

Soil Marginal Effect and LSTM Model in Chinese Solar Greenhouse.

The food crisis has increased demand for agricultural resources due to various factors such as extreme weather, energy crises, and conflicts. A solar greenhouse enables counter-seasonal winter cultivation due to its thermal insulation, thus alleviating the food crisis. The root temperature is of critical importance, although the mechanism of soil thermal environment change remains uncertain. This paper presents a comprehensive study of the soil thermal environment of a solar greenhouse in Jinzhong City, Shanxi Province, employing a variety of analytical techniques, including theoretical, experimental, and numerical simulation, and deep learning modelling. The results of this study demonstrate the following: During the overwintering period, the thermal environment of the solar greenhouse floor was divided into a low-temperature zone, a constant-temperature zone, and a high-temperature zone; the distance between the low-temperature boundary and the southern foot was 2.6 m. The lowest temperature in the low-temperature zone was 11.06 °C and the highest was 19.05 °C. The floor in the low-temperature zone had to be heated; the lowest value of the constant-temperature zone was 18.29 °C, without heating. The minimum distance between the area of high temperature and the southern foot of the solar greenhouse was 8 m and the lowest temperature reading was 19.29 °C. The indoor soil temperature tended to stabilise at a depth of 45 cm, and the lowest temperature reading at a horizontal distance of 1400 mm from the south foot was 19.5 °C. The Fluent and LSTM models fitted well and the models can be used to help control soil temperature during overwintering in extreme climates. The research can provide theoretical and data support for the crop areas and the heating of pipelines in the solar greenhouse.

Embryonic and larval development of yellow perch (Perca flavescens) and its sensitivity to incubation temperature.

The ontogenetic development in teleost fish is sensitive to temperature, and the developmental rate has a direct relationship with the environmental temperature within a species' thermal tolerance limit. Temperature determines time to and survival at hatching. Yellow perch is a North American species of ecological and commercial importance, and its phenology is vulnerable to climate change. The embryonic development of yellow perch was comparable to closely related members of the family Percidae. Developmental progression was fastest at 18°C and slowest at 12°C, with medial progression at 15°C. Time to hatch and swim-up, feeding onset, and exogenous feeding phases were different across all incubation temperatures regardless of a gradual post-hatch warming of the 12 and 15°C groups to a common garden temperature of 18°C. Incubation temperature may lower the rate of survival to hatch at 15°C and had complex impacts on developmental abnormalities. Temperature had significant effects on the development rate, time of hatch, survival, and incidence of developmental abnormalities. Early ontogenetic thermal history in ectotherms is an important factor determining phenotypic variation. It will be important to link the thermally induced changes in development described here to the physiological and morphological differences and to link the developmental abnormalities to functional performance.

How hydrological components of urban blue space influence the thermal milieu?

Present study examines the possible improvement of thermal discomfort mitigation. Unlike prior researches, which focused primarily on cooling effects of urban blue space, this study, instead of physical presence of blue space considers its hydrological components. The aim of the study is to better understand the role hydrological components like water consistency depth etc. In temperature regulation. The work uses field surveys and modeling to demonstrate how these hydrological factors influence the cooling effect of blue space, providing insights on urban thermal management. To fulfill the purpose, spatial association of hydrological components blue space with its thermal environment and cooling effects was assessed. The control of hydrological components on the surrounding air temperature was examined by conducting case studies. RESULTS: reveals greater hydro-duration, deeper water, and higher Water Presence Frequency (WPF) produce greater cooling effects. The study demonstrates a favorable correlation between hydrological richness and temperature reduction. The study also analyzes how land use and wetland size affect temperature, emphasizing the significance of hydrological conservation and restoration for successful temperature mitigation. Due to their hydrology, larger wetlands are able to moderate temperature to some extent, whereas smaller, fragmented wetlands being hydrologically poor are not so influential in this regard. With these results, the present study reaches beyond to the general understanding regarding the cooling effects of the urban blue spaces. While the previous studies primarily focused on estimating the cooling effect of urban blue space, the current one shows its synchronization with the hydrological characteristics. Novelty also entrusts here, through the modeling and field survey current study demonstrates deeper and consistent water coverage in the urban blue space for maximum period of a year pronounces the cooling effect. In addition, in this cooling effect, the role of land use which is a strong determinant of many aspects of the urban environment is also highlighted. Since all these findings define specific hydrological feature, the study has several practical implications. Mare restoration of urban blue space is not enough to mitigate the thermal discomfort. In order to optimize the cooling effect, the conservation of the hydrological richness is essential. The hydrological richness of the smaller wetlands and the edge of the larger wetlands is to be improved. The connection of these wetlands with the adjacent mighty may strengthen the hydrology. The vegetation was found to promote the cooling effect whereas shorter building helped in spreading the cooling effect. Such finding drives to incorporate the blue space with the green infrastructure along with restricting the building height atleast at the edge of the blue space.

Predicting the impacts of urban development on urban thermal environment using machine learning algorithms in Nanjing, China.

The urban thermal environment undergoes significant influences from changes in land use/land cover (LULC). This article uses CA-ANN and ANN algorithms to forecast LULC and changes in the urban thermal environment in Nanjing for the years 2030 and 2040. It investigates the interplay between LULC changes, land surface temperature (LST), and the urban thermal field variance index (UTFVI). The findings reveal that urban land exhibited a significant expansion trend from 2000 to 2019, reaching 1083.43 km2 in 2019. The forecast indicates that urban land may increase by 8.79% and 10.92% by 2030 and 2040, respectively. Conversely, vegetation and bare land may decrease. The LST is likely to continue to rise, accompanied by a significant expansion of the high temperature range and a contraction of the low temperature range. By 2030 and 2040, the area with LST<20 °C is likely to decrease by 2.17% and 3.19%, while the area with LST>30 °C is likely to expand by 5.68% and 8.08%, respectively. The UTFVI area of urban land may decrease at none and middle levels but may notably expand at stronger and strongest levels. The areas with UTFVI at none, weak, and middle levels show a declining trend, while the increase in UTFVI at the strong level may exceed 46.29% and the strongest level of UTFVI may continue to expand. This study offers new insights into urban sustainable development and thermal environment governance.

Determinants of subjective outdoor thermal comfort in an urban historic and cultural heritage landscape in Xi'an, China.

In this study, we investigated factors related to subjective outdoor thermal comfort in the Ancient Ming Dynasty Walled City in Xi'an, China. Environmental data were collected from study sites by microclimate monitoring. Survey locations, demographics, psychological characteristics, thermal sensation vote (TSV), and thermal comfort vote (TCV) data were collected from 639 individuals in a questionnaire survey. Generalized linear regression analysis and path analysis were used to understand the associations between the TSV, environmental and psychological factors, and TCV. We found that green space locations, higher age, and greater subjective well-being and environmental satisfaction were associated with increased TCV. The universal thermal climate index was associated with TCV, and this association could have been affected by the individual's psychological state. Our findings suggest that environmental factors and psychological factors had non-negligible effects on the subjective thermal comfort of individuals located in an open urban area with historical and cultural significance.

Assessing the land use dynamics and thermal environment using geospatial techniques in the industrial city of Chotanagpur Plateau Region, India.

The phenomenon of urban heat island (UHI) is characterized by industrial, economic development, unplanned and unregulated land use as well as a rapid increase in urban population, resulting a warmer inner core in contrast to the surrounding natural environment, thus requiring immediate attention for a sustainable urban environment. This study examined the land use/land cover (LULC) change, pattern of spectral indices (Normalized Difference Vegetation Index, NDVI; Normalized Difference Water Index, NDWI; Normalized Difference Built-up Index, NDBI and Normalized Difference Bareness Index, NDBaI), retrieval of land surface temperature (LST) and Urban Thermal Field Variance Index (UTFVI) as well as identification of UHI from 2000 to 2022. The relationship among LST and LULC spectral indices was estimated using Pearson's correlation coefficient. The Landsat-5 (TM) and Landsat-8 (OLI/TIRS) satellite data have been used, and all tasks were completed through various geospatial tools like ArcGIS 10.8, Google Earth Engine (GEE), Erdas Imagine 2014 and R-Programming. The result of this study depicts over the period that built-up area and water bodies increased by 119.78 and 35.70%, respectively. On the contrary, fallow and barren decreased by 55.33 and 32.31% respectively over the period. The mean and maximum LST increased by 3.61 °C and 2.62 °C, and the study reveals that a high concentration of UTFVI and UHI in industrial areas, coal mining sites and their surroundings, but the core urban area has observed low LST and intensity of UHI than the peripheral areas due to maintained vegetation cover and water bodies. An inverse relationship has been found among LST, NDVI and NDWI, while adverse relationships were observed among LST, NDBI and NDBaI throughout the period. Sustainable environment planning is needful for the urban area, as well as the periphery region and plantation is one of the controlling measures of LST and UHI increment. This work provides the scientific base for the study of the thermal environment which can be one of the variables for planning of Asansol City and likewise other cities of the country as well as the world.

Thermal Plasticity in Behavioral Traits Mediates Mating and Reproductive Dynamics in an Ectotherm.

AbstractEnvironmental temperatures potentially influence reproductive performance and sexual selection by restricting opportunities for activity. However, explicit tests of the behavioral mechanisms linking thermal variation to mating and reproductive performance are rare. We address this gap in a temperate lizard by combining social network analysis with molecular pedigree reconstruction in a large-scale thermal manipulation experiment. Populations exposed to cool thermal regimes presented fewer high-activity days compared with populations exposed to a warmer regime. While plasticity in thermal activity responses in males masked overall differences in activity levels, prolonged restriction nevertheless affected the timing and consistency of male-female interactions. Females were less capable than males of compensating for lost activity time under cold stress, and less active females in this group were significantly less likely to reproduce. While sex-biased activity suppression appeared to limit male mating rates, this did not correspond to a heightened intensity of sexual selection or shifts in the targets of sexual selection. In many populations facing thermal activity restriction, sexual selection on males may play a limited role relative to other thermal performance traits in facilitating adaptation.

The contrasting effects of fluctuating temperature on bacterial diversity and performances in temperate and subtropical soils.

The extremely high species diversity of soil bacterial community has fascinated and puzzled community ecologists. Although theory predicts that fluctuations in environments can facilitate diversity maintenance, the effects of fluctuating temperature on species diversity have rarely been investigated in species-rich microbial communities. Here, we examined whether fluctuating temperature had positive effects on species diversity relative to constant temperatures in soil bacterial communities, and investigated the effects of fluctuating temperature on bacterial performances (changes in relative abundance). We performed a temperature manipulation experiment with soils collected from temperate and subtropical zones, where the soils were subjected to constant high, low or fluctuating temperatures. We found that fluctuating temperatures showed significant positive effects on species diversity. The time-averaged effect of fluctuating temperatures (i.e., averaging out the differences between species in their environment-dependent performances) appeared to delay species loss in both the temperate and the subtropical communities. In addition, we found that the performances of temperature-responsive species at fluctuating temperatures significantly deviated from their time-weighted average performances at constant high and low temperatures, which was defined as fluctuation-dependent effects in our study. Intriguingly, fluctuation-dependent effects beyond time-averaged effect led to an opposite trend: differences in temperature-responsive species' performances decreased in the temperate communities, but increased in the subtropical communities. Our findings provide new insights into diversity maintenance in soil bacterial communities, and imply that the effects of fluctuating temperature on species diversity in soil bacterial community might vary across latitude.

The adaptive role of melanin plasticity in thermally variable environments.

Understanding the evolution of adaptive plasticity is fundamental to our knowledge of how organisms interact with their environments and cope with environmental change. Plasticity in melanin pigmentation is common in response to variable environments, especially thermal environments. Yet, the adaptive significance of melanin plasticity in thermally variable environments is often assumed, but rarely explicitly tested. Furthermore, understanding the role of plasticity when a trait is responsive to multiple environmental stimuli and plays many functional roles remains poorly understood. We test the hypothesis that melanin plasticity is an adaptation for thermally variable environments using Hyles lineata, the white-lined sphinx moth, which shows plasticity in melanin pigmentation during the larval stage. Melanin pigmentation influences thermal traits in H. lineata, as melanic individuals had higher heating rates and reached higher body temperatures than non-melanic individuals. Importantly, melanin pigmentation has temperature specific fitness consequences. While melanic individuals had an advantage in cold temperatures, neither phenotype had a clear fitness advantage at warm temperatures. Thus, the costs associated with melanin production may be unrelated to thermal context. Our results highlight the importance of explicitly testing the adaptive role of plasticity and considering all the factors that influence costs and benefits of plastic phenotypes across environments.

Assessment of green roofs' potential to improve the urban thermal environment: The case of Beijing.

Against the backdrop of global warming, rapid urbanization has caused the aggregation of urban building spaces and the heat island effect is becoming increasingly serious, hindering sustainable urban development. In order to investigate the potential and methods of green roofs in different types of neighborhoods to mitigate the urban heat island effect, this study used multivariate data for surface temperature inversion and local climate zone (LCZ), and the potential of green roofs to reduce the heat island effect was evaluated by combining LCZ zoning and ENVI-met prediction model. Finally, a multi-scenario analysis with economic factors was conducted to derive the optimal implementation path for green roofs. The results show that in LCZs 1-9, the green roof can reduce the daytime average air temperature by a maximum of 0.41 °C for 0.5 m of the LCZ8 roof and 0.37 °C for 1.2 m of the LCZ6 pedestrian. Based on the surface cooling efficiency of LCZ green roofs get the best green roof construction order: LCZ3, LCZ6, LCZ8 > LCZ2, LCZ5, LCZ7 > LCZ1, LCZ4, LCZ9. The construction of green roofs for the heat island areas within the fifth ring road of Beijing can reduce the area of high-temperature and sub-high-temperature zones by 52.55% and 29.17%, respectively, compared with the area without green roof construction. The study clarifies the technical methodology system of cooling efficiency of green roofs in different types of neighborhoods and the reduction of the urban-scale heat island effect, which provides a reference for the planning of green roofs for urban buildings.

Anthropogenic heat variation during the COVID-19 pandemic control measures in four Chinese megacities.

Anthropogenic heat (AH) is an important input for the urban thermal environment. While reduction in AH during the Coronavirus disease 2019 (COVID-19) pandemic may have weakened urban heat islands (UHI), quantitative assessments on this are lacking. Here, a new AH estimation method based on a remote sensing surface energy balance (RS-SEB) without hysteresis from heat storage was proposed to clarify the effects of COVID-19 control measures on AH. To weaken the impact of shadows, a simple and novel calibration method was developed to estimate the SEB in multiple regions and periods. To overcome the hysteresis of AH caused by heat storage, RS-SEB was combined with an inventory-based model and thermal stability analysis framework. The resulting AH was consistent with the latest global AH dataset and had a much higher spatial resolution, providing objective and refined features of human activities during the pandemic. Our study of four Chinese megacities (Wuhan, Shanghai, Beijing, and Guangzhou) indicated that COVID-19 control measures severely restricted human activities and notably reduced AH. The reduction was up to 50% in Wuhan during the lockdown in February 2020 and gradually decreased after the lockdown was eased in April 2020, similar to that in Shanghai during the Level 1 pandemic response. In contrast, AH was less reduced in Guangzhou during the same period and increased in Beijing owing to extended central heating use in winter. AH decreased more in urban centers and the change in AH varied in terms of urban land use between cities and periods. Although UHI changes during the COVID-19 pandemic cannot be entirely attributed to AH changes, the considerable reduction in AH is an important feature accompanying the weakening of the UHI.

Thermal comfort thresholds for Japanese quails based on performance and egg quality.

Knowledge of the effects of thermal stress on Japanese quails helps support decision-making regarding the management of climate control systems. Thus, the objective of this study was to evaluate the performance and egg quality of Japanese quails subjected to different air temperatures (tair) and to propose thresholds for the temperature-humidity index (THI), the Black globe humidity index (BGHI), and enthalpy (H). Two experiments (21 days each) were conducted in four climate-controlled wind tunnels. In the first experiment, tair was 20, 22, 24, and 26 °C, and in the second, tair was 20, 28, 30, and 32 °C. The relative humidity (RH) and air velocity were 60% and 0.3 ms-1, respectively. To define the comfort thresholds, the productive performance of the birds, water intake, and egg quality were evaluated. No differences were observed (p > 0.05) for the performance-related variables, except for feed intake, which decreased (p < 0.05) as tair increased, and water intake, which increased (p < 0.5) by 15.9% starting at 28 °C. For experiments 1 and 2, with tair at 20 °C (tair,obs = 20.8 and 21.3 °C, respectively), there was evidence of cold stress. The shell thickness, Haugh unit, and internal quality unit were negatively influenced (p < 0.05) by tair starting at 28 °C. Japanese quails were able, within certain limits, to adapt to continuous thermal stress. The Japanese quails thermal comfort intervals recommended for THI, BGHI, and H are 68.4 to 76.2, 69.1 to 77.2, and 50.5 to 67.2 kJ kgdry air-1, respectively.

Applied nucleation under high biodiversity silvopastoral system as an adaptive strategy against microclimate extremes in pasture areas.

This study aimed to assess the influence of the high biodiversity silvopastoral system (SPSnu) on the microclimate, pasture production, and pasture chemical composition. Microclimate variables and pasture production and chemical composition were measured in pared paddocks under SPSnu and treeless pasture (TLP) in a commercial farm during four seasons in Southern Brazil. SPSnu measurements were subdivided into two areas: around the nuclei (AN) and area inter-nuclei (IN). In the TLP paddocks, we plotted fictitious nuclei with the same areas and distributions of SPSnu, however without trees. For the microclimate measurements, these areas were noted when shaded or unshaded by the nuclei trees. In each season, the microclimate variables air temperature (AT, °C), relative humidity (RH, %), illuminance (Ilu, lux), wind speed (WS, m/s), and soil surface temperature (SST, °C) were measured. In addition, botanical composition (%), pasture production (kg/DM/ ha), and pasture chemical composition were evaluated. The SPSnu provided the lowest values of microclimate variables in all seasons (p < 0.05), except for the relative humidity. Winter had the highest thermal amplitude in the systems. The highest difference between SPSnu and TLP for AT (4.3 °C) and SST (5.2 °C) was measured during the hot seasons (spring and summer). In contrast, during cold seasons (autumn and winter) it observed highest thermal amplitude between SPSnu and TLP. Overall, the highest annual pasture production was observed in the SPSnu (p < 0.05). During the summer, the SPSnu areas showed the highest values of crude protein and dry matter (p < 0.05). During the winter, the TLP showed the lowest values (p < 0.05) of pasture production and dry matter. It was observed that SPSnu improved the microclimate at the pasture level, influencing pasture production and pasture chemical composition. The enhanced microclimate can partially mitigate some of the effects of climate change on pastoral agroecosystems, creating conditions for ecological rehabilitation of ecosystem processes and services. These conditions could be amplified to a biome level through a payment for ecosystem services program.

The impact of tree species and planting location on outdoor thermal comfort of a semi-outdoor space.

Previous studies have shown that tree arrangement provides effective regulation of the outdoor thermal environment and combats the urban heat island (UHI) effect. To further explore semi-outdoor thermal environment improvement using tree arrangement, we selected two common arbor species from Guangdong Province, namely, Lagerstroemia speciosa and Bombax ceiba. We discuss the influence of courtyard tree arrangements on the thermal environment of semi-outdoor spaces (courtyards and overhead spaces) of a teaching building in a hot-humid area. The ENVI-met model was used and verified with field measurements; the universal thermal climate index (UTCI) was used as an index to evaluate the thermal environment of semi-outdoor spaces. We found that (1) adjusting the distance between trees and buildings reduced the UTCI values by 0.4 (overhead spaces) and 0.8 ℃ (courtyards); and (2) when the distance between the arbor and the building is fixed, the UTCI values of arranging Lagerstroemia speciosa can be reduced by up to 0.5 (overhead spaces) and 1.0 ℃ (courtyards) compared to that of Bombax ceiba; this study provides practical suggestions for the layout of trees in semi-outdoor spaces of teaching buildings in the hot-humid areas of China.

Case Study: Impacts of Air-Conditioner Air Supply Strategy on Thermal Environment and Energy Consumption in Offices Using BES-CFD Co-Simulation.

Due to energy constraints and people's increasing requirements for indoor thermal comfort, improving energy efficiency while ensuring thermal comfort has become the focus of research in the design and operation of HVAC systems. This study took office rooms with few people occupying them in Wuhan as the research object. The EnergyPlus-Fluent co-simulation method was used to study the impact of 12 forms of air distribution on the thermal environment and air-conditioner energy consumption. The results indicate that 3 m/s supply air velocity and 45° supply air angle are more suitable for the case model in this study. The EnergyPlus-Fluent co-simulation method used in this paper provides a reference for the study of indoor environments in offices with few people occupying them.

Optimal local skin temperatures for mean skin temperature estimation and thermal comfort prediction of seated person in thermally stratified environments.

Thermally stratified environments are universal in "real world" buildings. However, the studies on the machine learning model and mean skin temperature (MST), which was based on the analysis of Local Skin Temperatures (LSTs), were insufficient in thermally stratified environments. To create thermally stratified environments in this study, the air temperatures at the lower body parts in a climatic box were controlled independently from the upper body parts exposed in climate chamber, with 12 air temperature combinations of 22, 25, 28, and 31°C. Sixteen human subjects were recruited to collect thermal perceptions and measure their LSTs. The variations of LSTs and the optimal LSTs to estimate MST and predict thermal state were analyzed. Based on the classifications of LSTs and area of local skin, a new method using chest (0.42), forearm (0.21), thigh (0.30), and foot (0.07) was proposed to estimate MST. Its errors decreased by at least 22.8% as compared to the existing methods. Then, the model based on Random Forest was used to filter the optimal LSTs for the predictions of Thermal Sensation Vote (TSV) and Local Thermal Comfort (LTC). Results showed at least three LSTs were needed to reach a robust model prediction accuracy and generalization ability. The optimal LSTs for the predictions of TSV and LTC were (Forearm, upper arm, foot) and (Forearm, chest, thigh), respectively. This study contributes to provide the basic information of optimal LSTs to improve the accuracies of the thermal comfort predictions and MST estimation in the thermally stratified environments.

An individualized and multi-segmental bioheat model for predicting local conditions of the human body under various thermal environments.

Thermoregulatory bioheat models have attracted the attention of researchers due to their conformity with the basis of human thermal perception. For this reason, various models have been presented, such as simplified thermoregulatory bioheat (STB), individualized thermoregulatory bioheat (ITB), and multi-segmental thermoregulatory bioheat (MSTB). In the present study and based upon previous models, an individual multi-segment thermoregulatory bioheat (IMTB) model has been introduced. In this model, the body is subdivided into 17 segments and 3 layers, with the blood circulatory system consisting of arteries, veins, and superficial veins. Also, IMTB can evaluate the individual parameters effects (such as height, weight, gender, and age) on physiological parameters and active/passive systems. Finally, this new model was evaluated in human thermal response predictions over a wide range of transient and steady-state environmental conditions (5.0< Tair(°C) <50.0, 31.0 < RH (%)<70.0) and various individual characteristics (male and female, 20 < age (years) < 69, 50