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• Research methods for assessing the thermal environment during sleep are reviewed. • The mechanisms of the thermal environment effects on sleep quality are summarized. • Thermal requirements for sleep vary between and within individuals. • The accuracy of 3 sleeping thermal comfort models is compared using 4 datasets. • Personalized regulation and integration with air quality are recommended. The sleeping thermal environment is crucial for maintaining the circadian rhythm and overall health. This paper systematically reviews the development of sleep thermal comfort research over the past two decades. We aim to review and analyse the impact of the sleeping thermal environment on sleep quality and thermal comfort, and to provide scientific insights for optimizing sleeping environments. First, the research methods for assessing the sleeping thermal environment are categorized into three groups: experimental studies, questionnaire surveys, and simulations. Second, we summarize the impact of the thermal environments on sleep quality and thermal comfort, considering occupants' subjective experiences, specific influencing factors, and individual differences in thermal sensation. Finally, the development of sleep thermal comfort models is reviewed, and their performance is evaluated using four sets of experimental data. Our findings indicate that relying solely on pre-sleep adjustments is insufficient to fully meet health and comfort needs during sleep. Factors such as indoor air temperature, humidity, airflow, and bed microclimate significantly affect sleep quality and sleep thermal comfort, with particular emphasis on the roles of airflow and bedding microclimate. Additionally, the study highlights differences in thermal requirements and perception between and within individuals. We conclude by identifying key areas for improvement and outlining future research directions to advance the field and enhance the design and control of practical sleep spaces. [ABSTRACT FROM AUTHOR]

• Research methods for assessing the thermal environment during sleep are reviewed. • The mechanisms of the thermal environment effects on sleep quality are summarized. • Thermal requirements for sleep vary between and within individuals. • The accuracy of 3 sleeping thermal comfort models is compared using 4 datasets. • Personalized regulation and integration with air quality are recommended. The sleeping thermal environment is crucial for maintaining the circadian rhythm and overall health. This paper systematically reviews the development of sleep thermal comfort research over the past two decades. We aim to review and analyse the impact of the sleeping thermal environment on sleep quality and thermal comfort, and to provide scientific insights for optimizing sleeping environments. First, the research methods for assessing the sleeping thermal environment are categorized into three groups: experimental studies, questionnaire surveys, and simulations. Second, we summarize the impact of the thermal environments on sleep quality and thermal comfort, considering occupants' subjective experiences, specific influencing factors, and individual differences in thermal sensation. Finally, the development of sleep thermal comfort models is reviewed, and their performance is evaluated using four sets of experimental data. Our findings indicate that relying solely on pre-sleep adjustments is insufficient to fully meet health and comfort needs during sleep. Factors such as indoor air temperature, humidity, airflow, and bed microclimate significantly affect sleep quality and sleep thermal comfort, with particular emphasis on the roles of airflow and bedding microclimate. Additionally, the study highlights differences in thermal requirements and perception between and within individuals. We conclude by identifying key areas for improvement and outlining future research directions to advance the field and enhance the design and control of practical sleep spaces. [ABSTRACT FROM AUTHOR]

Healthy indoor environments have been acknowledged as one of main determinants affecting brain health given much time spent indoors throughout the lifecycle. However, most studies were often restricted to categorical studies regarding specific indoor factors including indoor air pollutants, noise, lighting, temperature and dampness, and brain health outcomes. There were few studies that systematically indicated the connection between indoor environment and brain heath across the life course. We searched eight databases for studies on the association between indoor environmental exposure and brain health from inception to March 13, 2024. Of 18,735 retrieved records, 91 articles were included in our study. Exposure to indoor air pollutants in early life or childhood can lead to cognitive decline and behavioral issues, increasing the risk of ADHD. Continuous exposure to PM 10 above 50 μg/m³ increased ADHD and behavioral issues in children. Especially an increase of 5 μg/m³ in PM 2.5 concentration was associated with a 50 % rise in the risk of developing ADHD. Adolescents exposed to poor environment quality may experience diminished cognitive functions, behavioral problems, and mental health disorders. Long-term exposure to nighttime noise levels above 55 dB can increase the incidence of depression or anxiety symptoms in adolescents by 4 %–26 %. Similarly, prolonged exposure to NO 2 over 26.5 μg/m³ can increase a 1.62 times greater risk of schizophrenia. For the middle-aged and elderly, cognitive impairments, depression, and neurodegenerative diseases were closely linked to indoor environmental quality. Prolonged exposure to high concentrations of unpurified fuel smoke can impair cognitive function, whereas the use of clean fuels can reduce the risk of depression. Cognitive function in adults declined by an average of 5 % with each 6 °C drop or 9 °C rise in indoor temperature. In environments where PM 2.5 levels exceed 25 μg/m³, each additional 1 μg/m³ of PM 2.5 can increase the risk of dementia in middle-aged adults by 55 %. The elderly were particularly vulnerable to prolonged exposure to PM 2.5 levels above 10 μg/m³, significantly diminishing their cognitive abilities. Poor indoor environment can have a direct or indirect impact on brain health by affecting the formation and release of neurotransmitters, neural plasticity and causing inflammation. This study will provide a basis to develop strategies for optimizing brain health at different stage of life. [ABSTRACT FROM AUTHOR]

Worker performance is affected by environmental stimuli in the office. Therefore, it is important to analyze the relationship between workers and multiple environment elements simultaneously in order to understand the relationship between the office environment and worker performance. In addition, surveying a large sample of offices simultaneously is desirable to obtain more practical insights. Therefore, this study surveyed multiple elements of the physical office environment related to worker performance in a large sample of offices. The elements of the physical office environment surveyed were air temperature, relative humidity, CO 2 concentration, and sound pressure level during the summer. Along with measurements from 58 offices across 29 buildings in Tokyo, Japan, 947 responses to a questionnaire survey of workers conducted to evaluate work performance were analyzed to elucidate the relationship between these elements of the physical office environment and perceived work efficiency. The analysis showed that air temperature was more related to worker performance than to the other elements. In addition, 25 °C air temperature group was observed to be associated with high worker performance, with worker performance being lowest in the 27 °C group. This finding is expected to provide insight into indoor environments that can effectively enhance office worker performance. • Measurement and questionnaire surveys were conducted in 58 offices in Tokyo, Japan. • Four physical elements were analyzed: Air temp., RH, CO 2 , and sound pressure level. • Air temperature was more related to worker performance compared with other elements. • Work performance was lowest when the air temperature was around 27 °C during summer. [ABSTRACT FROM AUTHOR]

Radiant cooling is widely acknowledged as an energy-efficient approach to indoor thermal environment regulation. It offers an improved environment in terms of thermal comfort, compared to traditional air-cooling methods, but suffers from condensation risk and insufficient cooling power in hot and humid climates. To overcome these limitations, an Air-Layer-Integrated Radiant Cooling Unit (AIRCU) was developed, which seals a layer of dry air between an infrared transparent membrane and the radiant cooling surface. This innovative approach allows the use of lower radiant cooling temperatures to increase cooling power while concurrently maintaining the membrane at a higher temperature to minimize the risk of condensation. In our previous studies, the heat transfer model of AIRCUs was established, and the feasibility of the concept was verified. However, there is a lack of research on the operating characteristics of AIRCUs. In this paper, both experimental and numerical studies are conducted to investigate the operating characteristics of the AIRCUs under diverse cooling temperatures, chilled water flow rates, and cooling loads. Results indicated that the thermal environment created by the AIRCUs was uniform, and it can be characterized by uncooled surface temperature and radiant cooling surface temperature. Under different load conditions, the chilled water supply temperature was suggested as the control variable to adjust the thermal environment. To satisfy the thermal comfort, the operative temperature should be controlled within 23.6 °C ∼26.4 °C. This study provides valuable guidance on operating variable settings and environmental control of the AIRCU and promotes its application. • AIRCU increased the ratio of radiant flux to total cooling capacity to 78 %. • AIRCU enhanced the control of indoor MRT rather than air temperature. • Water temperature is more effective than flow rate to control AIRCU cooling capacity. • Operative temperature for environments utilizing AIRCUs should be within 23.6-26.4°C. [ABSTRACT FROM AUTHOR]

Health problems due to heat or cold exposure is closely related not only to body temperature (BT) but also to blood flow rate (BFR) and blood pressure (BP). Therefore, it is necessary to understand the physiological mechanisms of the human body, such as how these physiological quantities change and how they affect each other. In this study, to clarify the physiological mechanisms of the human body, we measured the whole-body distribution of BT and BFR, as well as BP, heart rate, and metabolic rate under changes in ambient temperature and body posture. A total of 19 subjects were tested in three cases, including the temperature up-step and down-step cases, where the ambient temperature changed from 28 °C to 38 °C or 18 °C in the supine position, and the posture change case, where the posture changed alternately between the supine and standing positions at an ambient temperature of 28 °C. The results showed that the core temperature was efficiently maintained due to BFR regulation, especially in the extremities, in response to changes in ambient temperature. Additionally, changes in cerebral BFR in response to changes in posture were suppressed due to regulation of BFR, especially in the lower limbs, and heart rate. Furthermore, in the extremities, the BFR not only in the skin but also in the subcutaneous tissue and muscle was estimated to increase in hot environments and decrease in cold environments. • Blood flow rate (BFR), etc. were measured under temperature and posture changes. • Core temperature was maintained by regulating BFR, especially BFR in the limbs. • Cerebral BFR during standing was regulated mainly by lower-limb BFR and heart rate. • BFR in the subcutaneous tissue was estimated to change in hot/cold environments. • BFR in the muscle was also estimated to change in hot/cold environments. [ABSTRACT FROM AUTHOR]

With the changes in global climate and rapid urbanization, identifying the contribution of urban morphology to the thermal environment under different scenarios could be helpful in proposing differentiated optimization responses of different scenarios for improving the thermal environment by means of natural cooling. This study calculated 2D and 3D metrics and retrieved surface temperature based on building vector data, land use, electronic map, the remote sensing images. Then, the study of spatial scale sensitivity was developed to build a nested multi-scale Local Climate Zone (LCZ) (NMSLCZ) map. Finally, the eXtreme Gradient Boost (XGBoost) regression model was performed to explore the relative contributions of 2D and 3D morphologies of different LCZ scenarios to surface temperatures. The results of scale sensitivity analysis showed the size of the optimal spatial scale decreased with the increase in building height. The 3D morphologies show more significant effects on LST variations than 2D morphologies. The surface temperature mainly by built type is significantly higher than that mainly by land cover type. Scenarios representing dense trees, shrubs, low vegetation, and water have significant cooling effects. In the scenarios of built types, the surface temperature of compact and large low-rise buildings is higher than that of the other building forms. Our findings provide a new perspective for LCZ mapping of scale optimization of the thermal environment. Meanwhile, the contributions of 2D and 3D morphologies on LSTs could help urban planners and managers understand the impacts of climate change and propose relevant strategies toward sustainable cities. • Calculate 16 typical metrics representing 2D and 3D morphologies. • Accomplish LCZ classification mapping based on 9 spatial scales. • Construct a nested multi-scale Local Climate Zone (LCZ) (NMSLCZ) map according to the analysis of spatial scale sensitivity. • The XGBoost model is performed to analyze the contributions of 2D/3D morphologies of different LCZ scenarios to LSTs. [ABSTRACT FROM AUTHOR]

Occupancy dynamics can significantly influence indoor thermal environments, especially in large indoor spaces. It is difficult for conventional feedback control systems to respond promptly to occupancy dynamics because of the substantial thermal inertia of large spaces, which leads to unfavorable thermal conditions in environments regulated by such systems. To address this challenge, this study proposes an air supply control approach based on artificial neural networks (ANNs). In the proposed approach, a large space is divided into multiple zones and an ANN model is used to characterize the relationship between occupancy dynamics and the supply air flow rates of each zone, thereby expediting the response of the air-conditioning system to occupancy dynamics. First, a multi-zone thermal environment model was developed to accurately emulate the thermal behavior of each zone. Next, employing the developed model of the environment, the optimal air flow rates required for each zone to maintain the desired thermal environment were estimated for various boundary conditions, which were used as pretraining data for four candidate ANNs. Finally, the best-performing ANN candidate, Long Short-Term Memory (LSTM), was adopted in a case study building via a comparison against several conventional air supply control methods. The results from the case studies demonstrate that the proposed approach can effectively expedite the system response to occupancy dynamics, thereby minimizing the occurrence of overcooling and overheating, and lowering the occupancy-weighted thermal discomfort level by 73.1 %. The proposed approach holds promise for real-time applications based on digital twin architecture. [Display omitted] • A thermal environment model is developed to emulate thermal behaviors of large spaces. • The impacts of occupancy dynamics on temperature control are investigated. • An ANN-based air supply method is proposed to deal with occupancy dynamics. • This approach can lower the occupancy-weighted thermal discomfort level by 73.1 %. • Data-driven HVAC control holds application promise under digital twin architecture. [ABSTRACT FROM AUTHOR]

Over an extended period, the art museum prioritized regulating its thermal environment solely for the preservation of artworks, without considering the visitors' aesthetic experience. However, it is no longer an exception, given the ongoing development of HVAC systems. This research aims to investigate how museums' thermal environment and the resulting thermal comfort impact visitors' aesthetic experience. The experiment was performed to examine the subjects' aesthetic experience under three temperature conditions: 18 °C, 26 °C, and 32 °C. Subjects experienced VR museum exhibition, and their physiological responses, heart rates and variability were measured. Psychological responses were gathered through thermal comfort votes, and Aesthetic Experience Questionnaire (AEQ). As a result, the thermal comfort votes were highest in the order of 26 °C, 18 °C, and 32 °C. Aesthetic experience responses, measured by AEQ, were highest at 26 °C and lowest at 32 °C. This suggests that subjects enhanced aesthetic experiences in a thermally comfortable environment, while high temperature hindered them. Beyond temperature, factors like thermal sensation and comfort were considered influential in aesthetic experiences. Thermal sensation was found to impact aesthetic experiences in a quadratic manner, and thermal comfort had a positive effect on them. Lastly, physiological responses previously associated with aesthetic experiences showed no significant impact in this study. Only thermal sensation demonstrated a significant influence, attributed to thermoregulation responding to thermal environment changes. In other words, when the thermal environment changes, the physiological response can't reliably indicate aesthetic experiences due to the thermoregulation. This study is significant in proposing unexplored aspects of thermal environments in enhancing aesthetic experiences. • A thermally comfortable environment can support aesthetic experiences while high temperature could hinder them. • A slightly cool environment benefits cognitive aesthetic experience. • Thermal comfort had a significant positive effect on aesthetic experiences. • Heart rate and heart rate variability can't indicate aesthetic experiences with the change of thermal environment, due to the thermoregulation. [ABSTRACT FROM AUTHOR]

Understanding how elderly residents use neighbourhood squares is helpful for designing these public areas to maximize their usage and minimize heat exposure risks, especially given the global increase in heatwaves and initiatives for healthy aging in place. This study aims to explore the dynamic use of a neighbourhood square with multiple shade configurations by its elderly residents. In-situ observations and measurements in three squares in public housing estates in Hong Kong were conducted in hot summer days to learn the relationship between elderly users' usage behaviours and multiple driving factors, including outdoor thermal environment, level of social interaction, and different shade types. The relationship was then used to develop an agent-based model (ABM) to simulate the dynamic usage pattern in a square over a day. The result indicates that the dynamic usage pattern from 9:00 to 18:00 in a square emerges from interactions between elderly users' behaviours and shade configurations, which can be reasonably estimated by the developed ABM. Based on the ABM simulation, shade configurations that cover 60 % of the square and create microclimates with a maximum m P E T not exceeding 34.0 °C during summer days encourage square usage and mitigate heat-stress risks of elderly users. The prototype ABM enables the understanding of the complex usage pattern in a neighbourhood square and can potentially assist planning and optimization of shade configurations at the design/renewal stage. • Thermal environments in neighbourhood squares with multiple shade configurations during summer daytime. • Decision-making of elderly users on visiting, leaving, and staying in subareas. • Agent-based model to simulate the dynamic usage pattern of a square by elderly users. • Optimal shade configurations to encourage the elderly's usage and reduce their heat-stress risks. [ABSTRACT FROM AUTHOR]

The process of urbanization exacerbates the urban heat island phenomenon. In order to reasonably identify urban functional zones, and reveal the influence of buildings on land surface temperature (LST). Guiyang, a multi-mountainous city in China, was taken as the research area, Open Street Map (OSM) and land use type data were used to identify urban functional zones. Subsequently, the correlation between urban building morphology metrics and LST was analyzed using Pearson correlation and boosted regression tree (BRT) model. The results showed that: (1) There were significant differences in LST among different urban functional zones. (2) The relative contribution value of building density (BD) to land surface temperature was high, and it significantly exacerbated the urban heat island effect across all urban functional zones, with the maximum impact on LST reaching 2.5 °C in Utility zone. (3) Mean building height (MBH), Southerly wind speed (S_Wind speed) and Landscape shape index of building (LSI_Building) had the effect of alleviating thermal environment, and the mitigation degree of land surface temperature was the highest in Residential zone and Ecological zone, reaching 0.6 °C, 0.8 °C and 2.0 °C, respectively. This study enhances our understanding of the relationship between urban functions and LST, providing valuable insights for mitigating the urban thermal environment and promoting sustainable development. [Display omitted] • There are significant differences in LST among different urban functional zones. • Building density is positively correlated with LST in all urban functional zones. • Southerly wind speed attenuate the effect of urban heat island. • Optimizing urban building morphology metrics can alleviate thermal environment. [ABSTRACT FROM AUTHOR]

Blue-green spaces exhibit a cooling island effect in urban thermal environments. This study, through field measurements combined with thermal comfort indices and CFD simulations, explored the summer cooling island effect in micro-scale blue-green spaces of severe cold regions, summarizing the spatiotemporal characteristics of the effect. Measurements were conducted in Harbin at three water bodies of varying sizes and shapes, revealing a notable cooling island effect at a distance of 6–8 m from the water. The highest Mean Cooling Island Intensity (MCII) of 3.18 °C was recorded at 10 a.m. in a circular water body with compound vegetation. Furthermore, the combination of water bodies and vegetation proved more effective in reducing temperatures than single factors alone, with the peak coupling effect of 6.37 °C at 6 m from the water at 11 a.m. Thermal environment surveys determined Harbin's Neutral Universal Thermal Climate Index (UTCI) temperature range to be 13.3–25.06 °C. Additionally, modeling and optimization comparisons in ENVI-met confirmed that adding a small number of deciduous trees to grassland areas and altering the type of waterside platform can optimize the thermal environment. This research provides a solid foundation for the optimized design of blue-green spaces in severe cold regions. • Assessment and field measurement of blue-green spaces in severe cold regions. • Optimal cooling island effect occurs at 6m–8m from circular water with vegetation. • Spatiotemporal characteristics of coupling between water bodies and vegetation. • Thermal environment surveys reveal Harbin's NUTCIR to be between 13.3 and 25.06 °C. • Exploring optimization strategies for Blue-green spaces in severe cold regions. [ABSTRACT FROM AUTHOR]

Indoor occupants may receive large solar heat that affect their health, productivity, and comfort. Most of previous studies focus on indoor occupants with strong direct solar radiation and weak diffuse radiation. Considering the non-uniform solar radiation distribution in the sky, this study proposes the improved HNU Solar Model, a novel method for calculating solar radiation on indoor human body under different weather conditions. The improved HNU Solar Model proposes a new calculation algorithm for calculating non-uniform radiation distributed on indoor human body under different weather conditions, via adding the human body points, windows points, and clearness index to improve the calculation accuracy; then it converts the human-body-received solar radiation into the increase in the mean radiant temperature (Delta MRT). The calculated Delta MRT values by the improved HNU Solar Model were compared with those calculated by Radiance. The results indicate that, for Delta MRT by total solar radiation on typical days with different weather conditions, the absolute error (AE) and the relative error (RE) of the improved HNU Solar Model are usually less than 1.5 °C and 15%, respectively. For the whole-year hourly Delta MRT values, the corresponding AE and RE are usually less than 1 °C and 15%, respectively. Moreover, according to the proposed model, for large-window buildings in medium-latitude regions, indoor occupants are more exposed to direct solar radiation (63%) than diffuse solar radiation (37%); while diffuse radiation can be the dominant solar heat gain of indoor occupants (up to 55%) in buildings in low-latitude regions. [Display omitted] • The improved HNU Solar Model is proposed to evaluate solar heat on indoor bodies. • Body points, windows points, and clearness index are used to improve accuracy. • The model has high calculation speed and needs only 17 easy input parameters. • The model calculates detailed direct, diffuse, and reflected radiation separately. • The absolute error and relative error are less than 1.5 °C and 15%, respectively. [ABSTRACT FROM AUTHOR]

A pleasant outdoor thermal environment could substantially enrich residents' enjoyment for outdoor activities. However, previous studies on outdoor thermal comfort in humid subtropical regions have given limited attention to urban parks. This study aimed to explore the relationship between outdoor thermal comfort and spatial behaviors in urban parks located in humid subtropical regions. Physical measurements, questionnaire surveys, and behavioral observations were conducted to establish the thermal benchmarks in Xiamen, China, including neutral Physiological Equivalent Temperature (PET), neutral PET range, comfortable PET, and thermal acceptability range. The thermal discomfort factors and preferences for thermal environmental parameters were also identified. The results showed that the neutral PET in Xiamen's urban parks was 19.3 °C in spring and 24.7 °C in summer. In spring, the neutral PET range was found to be between 17.3 and 21.2 °C, whereas in summer, it expanded to 20.9 and 28.4 °C. Comfortable PET was 19.4 °C in spring, but no specific value was determined during the summer testing. In summer, the 90% thermal acceptability range of the residents was below 32.8 °C. Residents were observed to adapt to outdoor thermal conditions by adjusting their activities, such as the change in outdoor time, location, activity level, and clothing. To improve outdoor thermal comfort, it is important to consider the period of thermal discomfort and implement cooling shading measures during the summer, such as mist-spraying facilities or removable sunshade devices. This quantitative assessment of outdoor thermal comfort in urban parks could offer valuable insights for designing urban parks in humid subtropical regions. • Residents adapted to outdoor thermal comfort by adjusting behaviors. • Thermal comfort in urban parks of a humid subtropical climate was evaluated. • Thermal neutrality and acceptable thermal limits in terms of PET were determined. • The neutral PET in Xiamen's urban parks was 19.3 °C in spring and 24.7 °C in summer. [ABSTRACT FROM AUTHOR]

Buildings, hard surfaces, vegetation, and water bodies are the four main urban surface types in the study region that are categorized in this study. It uses summer land surface temperature (LST)1 data obtained with a spatial resolution of 1 × 1 m using thermal imaging mounted on a drone, with a case study centering on a small to medium-sized Chinese town. To assess urban spatial morphology indicators within different ranges around the sample sites, buffer zones at 30 m , 50 m , 100 m , and 150 m were developed. The study determined the effective response range, identified the important urban spatial morphology indicators influencing LST, and examined the link between summer LST and various urban spatial morphologies for the four surface types. The results show that, close to the sample locations, Natural Environment Indicators (NEI) often have a cooling effect whereas Building Indicators (BI) typically have a warming effect. The influence of spatial morphologies on summer LST was primarily centered between 30 m and 50 m from the sample sites. The primary spatial morphological indicators determining LST for various underlying surface types within various spatial ranges are the building structure index (BSI) and water surface rate (WP). The response modes, response ranges, and response intensities of LST, however, varied significantly among various underlying surface types. This work provides new insights into how urban morphological characteristics affect the fine-scale spatial variation of LST within urban heat islands (UHI). • Different types of surface LSTs are affected differently by spatial morphology. • In all sites, ABI warms LST, while NEI cools it. • While NEI generally cools, some surface types are warm. • Spatial morphologies mainly impacted LST within 30 m –50 m. [ABSTRACT FROM AUTHOR]

Large skylights in underground public transport hubs are designed to introduce natural light and reduce the energy consumed by artificial lighting. Although large skylights can improve the lighting environment of underground public transport hubs, they also increase energy consumption due to solar radiation. Therefore, there is an urgent need to balance the improved lighting and energy consumption associated with large skylights and to determine the optimal design scheme. There are few studies on the lighting and thermal environments of underground public transport hubs, and the optimal design scheme for large skylights is unclear. Therefore, in the current study, field tests were conducted to analyze the lighting and thermal environments of two underground public transport hubs located in Shenzhen: Shenzhen North Station and Futian Station. In addition, multiobjective optimization was carried out for the large skylight at Futian Station. The results showed that most passengers were satisfied with the lighting and thermal environment under large skylights, but they were less satisfied in the summer than in the winter. Therefore, appropriate shading measures should be considered to reduce the effect of large skylights on passengers' thermal comfort in the summer. Furthermore, the results of multiobjective optimization indicated that the large skylight at Futian Station led to a 28.1 % reduction in annual air conditioning-induced energy consumption, a 31.5 % increase in the lighting performance index (UDI), and a 43.8 % increase in the human thermal comfort index (CTR). The results of this study could provide guidance for the design of large skylights in underground public transport hubs. [Display omitted] • Field tested the effects of large skylights on the environments of underground public transport hubs. • Passengers were less satisfied with the environment under large skylights in summer than in winter. • The coupled dynamic simulation of large skylights' lighting and thermal environments was presented. • The optimal design method for large skylights in underground public transport hubs was proposed. [ABSTRACT FROM AUTHOR]

The present paper reports a meta-analysis of published evidence on the effects of temperature in school classrooms on children's performance in school. The data from 18 studies were used to construct a relationship between thermal conditions in classrooms and children's performance in school. Psychological tests measuring cognitive abilities and skills, school tasks including mathematical and language-based tasks, rating schemes, and tests used to assess progress in learning including end-of-year grades and the examination results were considered as indicators of children's performance Due to the lack of complete measurements, thermal conditions were characterized by measured classroom temperatures. To create the relationship, the fractional change in performance of psychological tests and school tasks was regressed against the average temperature at which the change was recorded; all published data were used regardless of whether the change in learning outcome changed significantly with temperature. For other learning outcomes, no relationship was created because the data were insufficient. The relationship derived in the analysis shows that the performance of psychological tests and school tasks can be expected to increase on average by 20% if classroom temperatures are lowered from 30 °C to 20 °C and that the temperature for optimal performance is lower than 22 °C. The relationship is valid only for temperate climates. It requires verification for other climates and extensions to temperatures lower than 20 °C and higher than 30 °C. • A relationship was developed between temperature and various indicators of learning outcomes. • It is based on data collected mainly in temperate climates concerning performance of psychological tests and school tasks. • Reducing temperature by 10 K from 30 °C to 20 °C is expected to increase performance of tasks relevant for learning by 20%. • The effects of temperature on schoolwork seems to be greater in magnitude than has been found for office work. • The optimal temperature for the performance of schoolwork seems to be lower than for office work. [ABSTRACT FROM AUTHOR]

Core and surface body temperature are physiological indicators commonly used in human-environment researches, but which specific body temperatures can characterize them have not been thoroughly explored. A case study was conducted in three stable thermal environments, where five kinds of body temperatures (intra-abdominal temperature, oral temperature, auditory canal temperature, breath temperature, and skin temperature) and two types of thermal perception (thermal sensation and thermal comfort) votes were regularly collected. Upon comparing measurements with theoretical classification principles, we found that both oral temperature and intra-abdominal temperature exhibited characteristics consistent with core temperature, while both mean skin temperature and breath temperature exhibited characteristics consistent with surface temperature. In addition, the comparison analysis between newly proposed indicators and gold standards further confirmed application prospects, as the average temperature difference between intra-abdominal and oral remained consistently below 0.1 °C, and the average temperature difference between skin and breath exhibited a slight fluctuation around fixed values. Generally, the findings of this study provide insights into the selection and application of body temperature indicators, while reminding researchers should not blindly follow the previous standards. • Two principals were summarized for core and surface body temperature classification. • Oral temperature and breath temperature can characterize core and surface temperature respectively. • The difference between oral and intra-abdominal temperatures remained below 0.1 °C. • A numerical relationship is established between thermal sensation vote and core temperature. [ABSTRACT FROM AUTHOR]

Most existing building thermal environment design methods focus on the overall environment without considering individual demands, which can result in inadequate comfort and unnecessary energy consumption. To address individual differences, appropriate measures must be followed at the individual level. This study presents the development of an automatic personal comfort system (APCS) for regulating the local environment of individuals by integrating two personal thermal comfort technologies, personal comfort system (PCS) and personal comfort model (PCM). The equipment enables thermal sensation prediction through infrared skin temperature and environmental parameters measurements, which is used to regulate the corresponding PCS device. The proposed thermal sensation prediction model based on random forest can achieve a prediction accuracy of 69%, while the PCS control strategy comprehensively considers thermal sensation vote (TSV) and airflow acceptability. The APCS performance test experiment involved 25 male adult subjects. The results indicated that PCS operating states were consistent under both manual and automatic control conditions. Moreover, TSV remained within the neutral zone for most participants throughout the experiment. These findings demonstrate that the APCS realized good automatic operation to ensure the comfort of the personnel. The APCS framework holds reference value for research on personal thermal comfort and future thermal environment construction, extending beyond the equipment itself. • Automatic personal comfort system developed for individuals. • Integrate the personal comfort system and personal comfort model. • Thermal sensation prediction based on infrared skin temperature measurements. • Control strategy considering thermal sensation and airflow acceptability. • Achieve good automatic control to ensure thermal comfort. [ABSTRACT FROM AUTHOR]

Current studies of the influence of urban morphology indicators on land surface temperature (LST) usually focus on administrative or grid-based research units, and the limited inclusion of similar indicators easily occurs due to multicollinearity. This study implements Random Forest (RF) models with multi-source data, to study the relative importance and marginal effects of eight building form indicators as well as six street view indicators on street-level LST across all four seasons for Shenzhen, China. Our results show that the RF models explained 79.56%, 79.07%, 76.42%, and 64.74% of the LST variations in the spring, summer, autumn and winter, respectively. The building view factor (BVF) and green view index (GVI) were identified as the two most important indicators across all seasons. However, BVF was the dominant indicator in the spring and summer, and GVI played more significant roles in the autumn and winter. The relative importance of building density (BD), average building height (BH), standard deviation of building height (BH_SD) and sky view factor (SVF) showed noticeable variations with the seasons as well. The trends of marginal effects remained stable for each indicator across the four seasons. BVF, BD and SVF had warming effects in each season, while GVI, BH and BH_SD had cooling effects in each season. These findings contribute to our understanding of the relationship between urban morphology indicators and LST and provide valuable design suggestions for improving urban thermal environment, especially in high-density cities. • The effects of urban morphology indicators on LST were analyzed by RF models. • The SegFormer model was used to extract street view indicators. • The BVF and GVI were the two most significant indicators among the four seasons. • BVF, BD, and SVF had warming effects, while GVI, BH, and BH_SD did the opposite. • The trends of marginal effects were similar for each indicator across four seasons. [ABSTRACT FROM AUTHOR]

Abstract Sleep is physically, physiologically, and psychologically affected by several factors. The present study mainly focused on the effects of the pre-sleep thermal environment on sleep quality. The physical heat transfer between body and thermal environment determines the thermal state and thermal sensation of a subject, thereby physiologically affecting human sleep. Chamber experiments were designed to construct three different pre-sleep environments, namely, cool, neutral, and warm, with corresponding air temperatures of 23, 26, and 29 °C, respectively. The environmental condition during sleep was equally set in the entire experiment (24 °C/50%). Physiological measurements used included EEG, EOG, and EMG recordings from lights off (23:00) to lights on (7:00) to stage sleep for further analysis and seven-point skin temperature measurement. The subjects were required to fill up questionnaires before and after sleep. Results indicated that a warm pre-sleep environment led to high total sleep time (TST) and sleep efficiency (SE) and low sleep onset latencies (SOLs) and number of awakenings (NOA). Meanwhile, a cool pre-sleep environment results in low TST and SE and high SOL, WASO, and NOA. With regard to sleep stage, more deep sleep (N3 stage) and REM sleep were discovered in subjects exposed to warm environment before sleep. Subjects who stayed in warm environment before sleep exhibited the highest scores with respect to ease of falling asleep, sleep satisfaction, and ease of awakening. Therefore, a neutral-warm thermal sensation and near-zero distal–proximal temperature gradient are the important indicators of low SOL. Furthermore, the inherent mechanism was discussed in the present study. Highlights • The pre-sleep environment has significant effects on SOL and N3 sleep duration. • The cool environment caused the worst performance in TCV, TAV and sleep quality. • A warm pre-sleep environment led to lower SOL and more deep sleep. • The pre-sleep TSV and DPG are the important indicators of lower SOL. [ABSTRACT FROM AUTHOR]

Abstract The air distribution in displacement ventilation (DV) mainly depends on the heat sources in the room. The solar radiation and cold window are strong heat source or heat sink in summer and winter. A pipe-embedded window (PEW) has been developed to address the heat gain/loss through the window. In this study, the performance of the system based on DV and radiant ceiling was compared with that based on DV and PEW. A room with two workstations and two thermal manikins was adopted in the experiment. The impact of human bioeffluents and passive contaminant sources were studied. The results show that the warm window and floor in summer and cold window in winter damaged the normal air distribution of DV. The vertical temperature gradient was weakened and the ventilation effectiveness was close to that of mixing ventilation. The normalized contamination concentration was almost 1 in both workstations in different conditions. On the contrary, the PEW was able to keep the nature of DV and eliminate the negative effect from window. The bioeffluents and heat was efficiently removed by the DV flow. The exhaust air temperature in PEW system was higher in summer and lower in winter compared with radiant ceiling system. Highlights • A pipe-embedded window (PEW) can address the heat gain/loss through the window. • The impact of human bioeffluents and passive contaminant sources were studied. • Hot or cold window damaged the normal air distribution of DV in summer and winter. • Without PEW, the ventilation effectiveness was close to that of mixing ventilation. • The PEW keep the nature of DV and eliminate the negative effect from window. [ABSTRACT FROM AUTHOR]

Abstract Currently, subway lines are being increasingly constructed in the northern severe cold regions of China. The average ambient temperature in this region is below −10 °C during winter. Therefore, the extreme climate and piston effect impose challenges for designers for enhancing the thermal environment of a metro station in severe cold season. In this study, one-dimensional modelling is developed using the IDA Simulation Environment (IDA) based on an actual metro line, and the results are validated by experimental data. Moreover, the thermal environment of a typical metro station in the control group, two traditional optimisation measures, and one new method are investigated in severe cold regions. The results indicate that the primary heat loss during winter is attributed to the cold air invasion caused by the piston effect from the entrances. The addition of a warm-air curtain individually at the entrance may not effectively prevent the intrusion of cold air. Furthermore, adding a door curtain can reduce the inlet air volume of the entrance, but reduce the outlet air volume of the entrance. Thus, the heat of the train brake cannot be effectively utilised to improve the station temperature. In addition, one new method using the piston wind principle was presented, and it can effectively prevent the cold wind and more effectively utilise the train braking energy to improve the temperature of the metro station. It serves as a guideline for subway environmental control system (ECS) design. Highlights • The heat loss at subway station is mainly attributed to air invasion caused by the piston effect. • The warm-air curtains method may not effectively prevent the intrusion of cold air. • The door curtains in the entrances may reduce the heat utilization of the train-braking. • A new local component is proposed to improve the station thermal environment. [ABSTRACT FROM AUTHOR]

Although clothing is a critical factor in assessing human thermal comfort, gender differences exist in thermal responses. This paper presents research on gender differences in adult physiological and psychological responses to the thermal environment, using 12 different clothing ensembles. The experiment was conducted at four air temperatures: 10, 16, 22, and 28 °C, with three different series of clothing ensembles in each air temperature. The main conclusions are as follows: women are more sensitive to a colder thermal environment. Their measured overall skin temperatures were lower than those of their male counterparts and the predicted values for cold environments. This was particularly true in the case of hands, feet, and lower body parts, resulting in women feeling colder than men in the same cold environment. However, there were no significant differences in thermal sensations between the genders when their measured skin temperatures were the same. Different body parts showed different levels of thermal adaption to cold environments: the head, hands, and lower body had lower neutral skin temperatures in cold environments than those recorded in a previous study of a neutral environment, especially in the case of women. Due to these physiological and psychological differences of local body, more men than women preferred to add warmer or additional pants in cold environments. This article provides information to help researchers and designers take gender differences into consideration when designing indoor thermal environments, helping to improve both thermal comfort and system efficiency. [ABSTRACT FROM AUTHOR]

Currently, comfort analyses of buildings equipped with thermoelectric air cooling or heating systems mainly focus on when occupants are in a wakeful state. In this study, both objective and subjective analyses of the sleeping behavior for fifteen (15) healthy occupants were conducted by exposing the occupants to two sleeping environments (i.e., test room equipped with the thermoelectric air duct cooling system (TE-AD) and naturally ventilated test room (NH)). The result shows that there were significant variations in the sleep satisfaction level in the test room with TE-AD and NH. Occupants felt more comfortable (5) and a slightly cooler thermal environment (3) while sleeping in the test room equipped with the TE-AD system. Their body movements, heart rate and sleeping stages shift from non-rapid eye movement (NREM) to rapid eye movement (REM) and then to the waking stage (WS), was less in test room with the TE-AD system as compared to NH. The occupants gave slightly hot (5) for indoor climatic ratings in NH room and felt a slightly uncomfortable (3) while sleeping. The PMV and PPD analyses showed that occupants were very sensitive to climatic conditions around bed and with slightly change in temperature (1.2 ± 0.4 °C) results in the shifting of sleeping stages. For the TE-AD room, the average occupant sleep onset latency was 19 ± 0.5 min, which is 20 ± 0.4 min lesser than NH room. [ABSTRACT FROM AUTHOR]

Harbin is located in the severe cold area of China with the outdoor mean air temperature reaching lower than −10 °C in January in winter. A passive ultra-low energy residential building was built in Harbin in compliance with the German passive house standard, the first passive house project in the severe cold climate zone of China. A post-occupancy evaluation of indoor environmental quality was conducted in the passive building (PB) during the 2015/2016 heating season. The physical parameters of indoor thermal environment and air quality were measured, in parallel with a subjective occupant survey. For comparative purposes conventional buildings (CBs) in the same community were also evaluated with the same protocols. The results show that the average indoor temperature was higher than the upper limit of thermal comfort range in the PB and low relative humidity resulting from the overheating was observed. The indoor temperature fluctuation is small, and the difference between the inner surface temperature and the air temperature in the PB is lower than that of the CBs due to the high performance envelopes, so that cold radiation was minimized. The air quality in the PB was improved compared to the CBs due to the additional mechanical ventilation system. The fresh air volume was sufficient and CO 2 , PM10 and PM2.5 concentrations in the PB significant lower than those in CBs. In general, passive house technologies applied in Germany are applicable in the severe cold area of China, but the overheating problem should be avoided by proper operational strategies. [ABSTRACT FROM AUTHOR]

Harbin is in the severe cold climate zone in China, where the outdoor air temperature is low in winter. The central heating system without terminal control is used in buildings in the area. A field study on thermal comfort was conducted in four types of buildings in Harbin during a same winter. Due to the broad range of outdoor air temperatures and the long heating period in Harbin winter, the heating period was divided into three stages. We focused on indoor thermal environment and human adaptability during the three phases. Some environmental parameters were measured together with subjective investigation, and totally 1747 valid questionnaires were collected. The results show that indoor temperature over 24 °C often occurred in the buildings during the heating period. The occupants felt warm but they expected the indoor temperature no change. The participants were more sensitive to temperature variations at the early heating phase (EH). They adapted to warm environment gradually from EH to LH. The occupants would open windows when indoor temperatures were high. Great energy savings could be achieved by reducing indoor air temperature in winter. The neutral temperatures were lower than the indoor air temperatures in the buildings, indicating that indoor temperatures were sometimes overheated. The indoor temperature should be reduced to the lower limit at EH and increased gradually in winter. The neutral temperatures in offices and university classrooms were lower than those in apartments and dormitories. Therefore, lower indoor air temperatures are recommended in design of public buildings for space heating. [ABSTRACT FROM AUTHOR]

Using air conditioners to cool down the indoor thermal environment is necessary to avoid the elderly exposing themselves to hot conditions in extreme weather. Considering the frequency occurrence of heatwave events, this study investigated air-conditioner operation behaviours and indoor thermal condition features during extremely hot summer periods to understand the elderly's thermal demand and their behaviour patterns of using air conditioners. Fifteen elderly residents from a caring home in Chongqing were recruited, and their air-conditioners' historical operation data and indoor and outdoor temperatures were continuously measured and retrieved from the air-conditioner manufacturing data warehouse. The results indicate that the elderly subjects were active in adjusting their air-conditioner settings with multiple daily actions of turning-on and setpoint-changing behaviours in the extremely hot summer period. The air-conditioner temperature setpoint preferred by the elderly subjects was between 27 °C and 30 °C, resulting in the indoor temperature mainly remaining in the range between 28 °C and 32 °C, which presented a negative relationship with the outdoor temperature. The elderly's daily air-conditioner operation in the extremely hot summer period can be clustered into four groups, including inactive-usage, afternoon-usage, night-usage and all-day-usage groups. The inactive usage group with short-term and discrete air-conditioner operation would prefer a fast-cooling setting, whereas the all-day usage group showed a higher setpoint-change frequency, indicating the dynamic cooling demand may exist in the elderly's long-term air-conditioner daily usage. • Long-term monitoring on the elderly's AC usage in the extremely hot summer. • The elderly were active in using ACs and adjusting AC temperature settings. • Four groups were clustered with different daily AC operation patterns. • 30 °C was the most common AC setpoint for the elderly in each daily period. • Discrete-with-fast-cooling and continuous-with-frequent-adjustment were usual modes. [ABSTRACT FROM AUTHOR]

In the vast developing world represented by China, the unsatisfactory thermal and humidity conditions among rural built environments are extremely harmful to the elderly-health in cold regions. The cave-dwellings maintain competent thermal stability, while with current refurbishment still cannot meet their relatively demanding thermal comfort needs. In fact, few studies have highlighted the optimisation effect of passive designs engaging various buffer spaces. Through experimental field measurements of representative cave dwelling and numerical simulations based on the DesignBuilder tool for the corresponding retrofit prototypes, this study investigated in detail the hidden correlations between key buffer space design variables (sunroom, under-eave gray space, courtyard, etc.) and the resulting indoor thermal and humidity performances for the elderly. The results of the study showed that:1) The average winter room temperatures of both heated (11.2 ± 1.5 °C) and unheated (6.4 ± 2.7 °C) rooms in traditional cave-dwellings fail to meet the recommended standard by World Health Organization (18 °C) and the Chinese national standard (16 °C–24 °C). 2) For living track temperature steps reduction, the southern sunroom has obvious impact (mostly <10 °C), while enclosed courtyards with glass-top can even enhance such performance (mostly <5 °C). 3) For boosting indoor temperatures in winter, sunroom with enclosed courtyard are most effective in unheated and heated conditions. As the first systematic work to reveal the thermal-enhancing effectiveness of the south-facing buffer space for cave-dwellings in cold climates, the research findings can assist optimizing-retrofitting for cave-dwellings among similar climatic regions globally. • To experimentally measure featured winter thermal environment of cave dwellings in cold region. • To experimentally examine buffer space impacts on winter indoor temperatures and temperature steps of cave dwellings. • To numerically validate key buffer space variable induced indoor thermal performances of cave rooms in winter. • To propose suitable buffer space design strategies for better winter thermal environments of cave dwellings in cold regions. [ABSTRACT FROM AUTHOR]

Epidemiological evidence suggests that outdoor climate strongly influences human health. However, since people spend 90% of their time indoors, the indoor environment may be a better indicator of epidemiological diseases and infections. Despite previous studies exploring the relationship between indoor and outdoor thermal environments, little is known about this relationship in China's subtropical countryside. This study aims to investigate the indoor-outdoor relationship of air temperature and relative humidity, examine the spatial and temporal variation characteristics of the indoor thermal environment, and estimate indoor thermal comfort. We monitored outdoor and indoor air temperature and relative humidity for two years using wireless IoT temperature/humidity button sensors in fourteen residential buildings. Our results show that the average vertical spatial variance range of air temperature was largest in summer (2.11 °C) and smallest in fall (1.23 °C), while horizontal spatial variation was negligible. The average daily temporal variation range was largest on the third floor (2.3 °C) and smallest on the first floor (1.5 °C). Indoor air temperatures were highly correlated with outdoor air temperatures, with a linear correlation coefficient greater than 0.9. The relationship between indoor and outdoor relative humidity was moderate, with an average correlation coefficient of 0.54. Furthermore, we found that almost all uncomfortable indoor air temperature points were lower than the lower temperature limit of the adaptive comfort band in all seasons, and almost no indoor temperatures in summer and winter were within the PMV comfort band. • We conducted the first long-term on-site monitor in the countryside of the HSCW area. • We determined strong correlation between indoor and outdoor air temperatures. • We identified almost all uncomfortable indoor temperatures below adaptive comfort limits. • We revealed the largest vertical air temperatures spatial variance in summer. [ABSTRACT FROM AUTHOR]

Recently, subways in China's severe cold regions have developed rapidly. Harbin, a typical city in a severe cold region, can reach the lowest outdoor temperature of −37.7 °C in winter, making the thermal environment of the underground tunnels a huge challenge. Due to the complexity of the subway environment, there are few long-term field measurements, and the research on entrance and exit lines is often neglected. In this study, the thermal environment of Harbin Metro Line 1/3 and the entrance and exit lines was measured and studied, the heat production of train operation and annual heat storage heat was calculated. The results show that climatic conditions, burial depth, operating phase of the tunnel, passenger flow, and driving interval have an impact on the thermal environment of the tunnel. The daily average temperature difference between the two ends of the entrance and exit lines reached a maximum of 27.4 °C in winter. The average air temperature of Line 1 in summer, transition season and winter were 4.0 °C, 1.0 °C and 2.5 °C higher than that of Line 3, and the heat generated per hour was 201 MJ–242 MJ higher than Line 3. Furthermore, the heat storage capacity of tunnels in severe cold region was significantly higher than that in hot summer and warm winter region, the maximum difference was 823 GJ. The monitoring data are useful for both analytical and numerical studies and this study provide a valuable reference for the construction and operation of subways in severe cold regions. • Long-term field test of the subway tunnel in severe cold regions was conducted. • Entrance and exit lines were easily affected by the outdoor than main line. • 0–3 months temperature delay between the tunnel wall and the outdoor. • Hourly heat production of Line 1 was 143MJ–242MJ higher than other lines. • Annual heat storage of the tested tunnels of Line 1/3 was 273 GJ and 980 GJ. [ABSTRACT FROM AUTHOR]

Composite ice shell buildings are a special type of architecture found in severe cold regions and have played an important role in ice and snow tourism in recent years owing to their ability to offer tourists a romantic and novel experience. We conducted a field study to examine the thermal environment of a typical composite ice shell building in Harbin, China. In the unheated hall and separate small room, the indoor air had an average temperature and relative humidity of −20.64 °C and 76.94%, and −17.71 °C and 79.57%, respectively. Surface heat flux measurement of the north-facing building envelope revealed that the thermal properties of composite and plain ice differed significantly, suggesting that composite ice may have a lower thermal conductivity. The natural ventilation rate of 48,041 m3/h corresponded to an air change rate of 6.86 h−1, making the thermal environment highly susceptible to outdoor meteorological conditions. In addition, we conducted a questionnaire survey to study the thermal sensation and thermal comfort of the tourists. The results showed that the mean thermal sensation for the foot and head were approximately "cold " and "slightly cool", respectively. The overall and mean thermal sensation for the hand were both between "cool" and "cold", and the mean thermal comfort was approximately "slightly uncomfortable". An adaptive thermal sensation prediction model suitable for composite ice shell buildings was developed through the study. These findings can assist in the design and construction of thermal environments that are better suited for short-term stays and specialty tourism. [Display omitted] • The thermal environment of a typical composite ice shell building was explored. • Extremely low temperature and high relative humidity are notable in this building. • Composite ice materials have a lower thermal conductivity than plain ice. • Mean TSV is between "cool" and "cold" and mean TCV is "slightly uncomfortable". [ABSTRACT FROM AUTHOR]

This study intends to investigate indoor thermal environment in homes with elderly people during heating season in Beijing, China. The investigation was performed from December 2016 to February 2017, involving both urban and rural houses. Heating equipment, indoor clothing and thermal sensation of the elderly, and indoor physical parameters were analyzed through subjective surveys and objective measurements. Results show that different types of heating systems/devices are used in urban and rural houses. Overall, the heating duration of rural houses is longer than that of urban houses in winter. In terms of indoor air temperature, urban elderly people experienced warmer and steadier thermal environments than rural elderly people. During the investigation, the average air temperature in living rooms/elderly people's bedrooms of urban houses was 21.9 ± 2.2 °C/21.5 ± 2.8 °C, significantly higher than 16.1 ± 3.5 °C/14.6 ± 3.3 °C of rural houses. Additionally, rural elderly people usually encountered a large temperature step between indoors and outdoors, due to frequent exit and entry. Despite of relatively low air temperatures in rural houses, the elderly reported that the indoor thermal environment was acceptable, since the elderly in rural areas wear thicker clothes indoors in winter. This also indicated the acceptable temperature for elderly people in rural areas was lower than that for elderly people in urban areas. It is noted that the acceptable temperature may not satisfy long-term physical health requirements of the elderly. More studies are needed to determine reasonable temperature for both thermal comfort and health of the elderly. [ABSTRACT FROM AUTHOR]

Beyond previous research topics assessing physiological or psychological effects of an indoor environment, the present study aims to investigate the effect of thermal sensations on people's emotional responses. For achieving this purpose, chamber experiments were conducted based on three different temperatures (PMV −2, 0, +2), and results were obtained from 139 participants' brain wave data. The emotional process depending on indoor temperature was not significant; however, that depending on subjective thermal sensations were statistically significant. Since participants felt same indoor thermal condition differently, the physical indoor temperature itself had no direct significant influence to their emotions. Positivity bias was observed when participants felt neutral and slightly warm, and negativity bias was observed in all other cases. This study supports the notion that the thermal environment affects occupants' emotional responses through subjective thermal sensations. [ABSTRACT FROM AUTHOR]

Along with the improvement of living quality, indoor thermal comfort has been drawing increasing attentions. In this paper, a comparison between South Europe, North America and Asia on winter indoor thermal environments, occupants' clothing insulations and their thermal sensations was conducted. The compared regions all locate in similar latitude range of temperate climate zone (northern latitude 39°54’∼53°31′). Field study data representing 10 cities chosen from ASHRAE RP-884, SCATs and China thermal comfort databases were used for the comparative study. It was observed that the indoor operative temperature and relative humidity varied from regions. European and North American cities had higher temperature while temperature of Chinese cities was the lowest. Among the three regions, indoor environments in Europe and China met well with the comfort requirements in their own regional or national standard, while North America had the highest ratio of matching the comfort zones no matter in which standard. Most of the off-comfort-zone conditions in Europe were due to overheating, contrary to those in China were mainly overcooling. Clothing insulation of Chinese was the highest and had a wider range. The winter neutral temperature for Europe, North America and China were 23.4, 22.7 and 21.7 °C respectively. A comparison between TSV and PMV was made and obvious deviation features were discovered. Europeans tend to feel colder than predicted when indoor temperature is out of the neutral zone. Chinese TSVs were closer to neutral than they were predicted by PMV, while North Americans showed an opposite result. [ABSTRACT FROM AUTHOR]

Free-hanging horizontal and vertical sound absorbers are commonly used in buildings for room acoustic control; however, when these sound absorbers are used in combination with Thermally Active Building Systems, they will decrease the cooling performance of Thermally Active Building Systems and this will affect the thermal indoor environment in that space. Therefore, it is crucial to be able to quantify and model these effects in the design phase. This study quantifies experimentally the effects of horizontal and vertical free-hanging sound absorbers on the cooling performance of Thermally Active Building Systems and on the thermal indoor environment. The experiments were carried out in a climate chamber configured as a two-person office room. Different ceiling coverage ratios were tested. In addition, a commercially available dynamic building simulation software was used with a recently developed plug-in for acoustic elements, which allows modeling free-hanging horizontal sound absorbers that partially cover the ceiling. With horizontal sound absorbers, the cooling performance of the Thermally Active Building System decreased by 11%, 23% and 36% for ceiling coverage ratios of 43%, 60% and 80%, respectively. With vertical sound absorbers, the decrease in cooling performance was 8%, 12%, and 14% for the corresponding cases, respectively. The numerical model predicted closely the cooling performance reduction, air temperatures and ceiling surface temperatures in most cases, while there were differences in mean radiant temperatures and cooling capacity coefficients, indicating that the model can be improved in certain aspects. [ABSTRACT FROM AUTHOR]

Inefficient controlling strategies in heating and cooling systems have given rise to a large amount of energy waste and to widespread complaints about the thermal environment in buildings. An intelligent control method based on a support vector machine (SVM) classifier is proposed in this paper. Skin temperatures are the only inputs to the model and have shown attractive prediction power in recognizing steady state thermal demands. Data were accumulated from two studies to consider potential use for either individuals or a group of occupants. Using a single skin temperature correctly predicts 80% of thermal demands. Using combined skin temperatures from different body segments can improve the model to over 90% accuracy. Results show that three skin locations contained enough information for classification and more would cause the curse of dimensionality. Models using different skin temperatures were compared. Optimal parameters for each model were provided using grid search technique. Considering the overfitting possibility and the cases without learning processes, SVM classifiers with a linear kernel are preferred over Gaussian kernel ones. [ABSTRACT FROM AUTHOR]

Energy conservation in buildings as a way to reduce the emission of greenhouse gases is forcing an urgent re-examination of how closely thermal and air quality conditions should be controlled in buildings. Allowing conditions to drift outside the optimum range would conserve very large amounts of energy and would in most cases have only marginal effects on health or subjective comfort. The question that then arises is whether occupant performance would be negatively affected and if so, by how much. This information is required for cost-benefit analyses. The answers in this paper are based on laboratory and field experiments that have been carried out since the massive increase in energy costs that took place in the 1970s. Although only a few of the mechanisms by which indoor environmental effects occur have been identified, it is already clear that any economies achieved by energy conservation will be greatly exceeded by the costs incurred due to decreased performance. Reducing emissions by allowing indoor environmental conditions to deteriorate would thus be so expensive that it would justify greatly increased investment in more efficient use of energy in buildings in which conditions are not allowed to deteriorate. Labour costs in buildings exceed energy costs by two orders of magnitude, and as even the thermal and air quality conditions that the majority of building occupants currently accept can be shown to reduce performance by 5–10% for adults and by 15–30% for children, we cannot afford to allow them to deteriorate still further. [ABSTRACT FROM AUTHOR]

Standardized methods for thermal comfort assessment already exist, namely the predicted mean vote (PMV) and the adaptive comfort model, both valid for groups of people. To identify whether a specific person is comfortable under different factors such as thermal, air quality, lighting, and acoustics, the only current reliable method is subjective evaluation. To reduce the need of occupant feedback, personal comfort models are currently being developed that aim to predict thermal response based on information from the occupant and its surroundings. These comfort models leverage machine learning tools and have been found to provide suitable estimations of personal comfort responses. According to the literature, an average prediction accuracy of 70–80% is attainable. Therefore, these models are promoted as innovative and efficient ways for comfort-based HVAC control. The challenge is however identifying the most relevant indicators and acquiring them in a simple way. Integrating anthropometric data, e.g., age, sex, and body mass index may represent a method for generating a personal comfort model. Including physiological data such as skin temperature, heart rate, and signal transformation could increase performance. Strong relationships were identified between subjective thermal response and physiological indicators, however their variation was not found to be governed solely by thermoregulation. Few automatic control implementation examples of personal comfort models using physiological indicators shows that challenges still exist. In order to achieve an accurate control, certain issues remain regarding acceptable thresholds for personal comfort model performance and the optimum set of indicators and combination to achieve it. [ABSTRACT FROM AUTHOR]

Most studies have been conducted on the impact of indoor environmental quality (IEQ) on occupants' task performance. However, most studies are based on the assumption that IEQ directly affects task performance. Different hypotheses have been proposed that contradict this conventional belief. The objective of this study is to examine the indirect effects of IEQ on task performance. To identify unknown mediating variables between IEQ and task performance, two research hypotheses were set up: (i) Emotion is the result of a physiological response change in the body and would be influenced by the IEQ in the built environment; and (ii) Task performance would be influenced by IEQ-evoked emotion of occupants. The partial least squares structural equation modeling (PLS-SEM) was employed to verify two interrelated research hypotheses and conduct mediating effect analysis using SmartPLS 3.3.1. The results of this study demonstrated the following: (i) IEQ has no direct effect on task performance but has an indirect effect mediated by dominance resulting from skin conductance; (ii) hot and humid thermal environment and unpleasant indoor air quality increase human skin conductance, which in turn leads to passive emotions. The passive emotions that are not under direct human control result in the degradation of task performance. Using the findings of this study, future smart offices need to collect human bio-signals and emotions and manage IEQ based on these data unlike past smart offices that considered only environmental factors. • The indirect effect of IEQ on work performance was analyzed by mediating emotions. • The PLS-SEM was employed to verify two interrelated research hypotheses. • The IEQ has no direct effect on task performance. • The IEQ has an indirect effect mediated by dominance resulting from skin conductance. [ABSTRACT FROM AUTHOR]

Urban heat disrupts the use of parks, although the extent of such disruptions remains disputed. Literature relies on "small data" methods, such as questionnaires, field studies, or human-subject experiments, to capture the behavioural response to heat. Their findings are often in contradiction with each other, possibly due to the small sample sizes, the short study period, or the few sites available in a single study. The rise of "big data" such as social media offers new opportunities, yet its reliability and usefulness remain unknown. This paper describes a study using Twitter data (tweets) to study park attendance under the influence of hot weather. Some 20,000 tweets geo-coded within major parks were obtained in Hong Kong over a period of three years. Field studies have been conducted in parallel in a large park covering the hot and cool seasons and some 40,000 attendance were recorded over three months. Both the "small" and "big data" were analyzed and compared to each other. Findings suggest that a 1 °C increase in temperature was associated with some 4% drop in park attendance and some 1% drop in park tweets. The differences between the two data sources be explained by the 'leakage' of indoor tweets to parks caused by GPS drift near buildings. The Universal Thermal Climate Index can better predict self-reported thermal sensations, compared with other biometeorological indicators. This study has contributed to methodologies and new evidence to the study of behaviors and thermal adaptations in an outdoor space, and geo-coded tweets can serve as a powerful data source. • Twitter data were used to study park attendance influenced by hot weather in Hong Kong. • "big data" and "small data" confirmed negative correlations between attendance and temperature. • 'Hotspots' identified from the two data sources were in agreement with each other. • The new data analysis protocol is of value for follow-up studies in monitoring outdoor activities. • UTCI can better explain thermal sensations compared with WBGT, OUT_SET* or PET. [ABSTRACT FROM AUTHOR]

The conventional (square and circular) column attachment ventilation theory has been developed for many years. However, it is still unclear whether the cross-shaped column can be effectively applied to column attachment ventilation. This paper compared three column attachment ventilation models (i.e., circular, square and cross-shaped) by numerical simulation and experimental methods, the latter of which were mainly employed to verify and optimize the CFD model. The air distribution of these three ventilation models was studied in isothermal mode. Five cross-shaped column air supply outlet opening modes under cooling conditions were proposed, and their effects on the thermal environment distribution in the occupied zone were investigated. The intersection of the two attached airflows in the inner concave surface of the cross-shaped column changed the trends of the axial velocity variation. The attached airflow created a larger impinging zone near the internal corner of the cross-shaped column compared with the other surfaces. With the fixed air supply parameters, the kinetic energy loss at the column bottom under cross-shaped column attachment ventilation (CS-CAV) increased by approximately 60 % compared with that under square column attachment ventilation (S-CAV). CS-CAV is not only an effective ventilation method but can also meet the comfort needs of different occupied zones, providing a design basis for CS-CAV in buildings. • Cross-shaped column attachment ventilation is as effective as other ventilation. • Airflows interact at column internal corner, affecting indoor air distribution. • Cross-shaped column has five air supply modes because of multi-section slot outlet. • Cross-shaped column attachment ventilation creates different thermal environments. [ABSTRACT FROM AUTHOR]

Public exercise facilities have recently emerged across China. This study aims to investigate the impacts of exercise intensity and thermal environment on thermal responses as well as examine the dynamic changes and differences in thermal responses during exercise. Using a controlled thermal chamber, university students were assessed at varying walking speeds under six thermal conditions, from −15 to 35 °C. Their psychological and physiological responses were observed and recorded in real time during the thermal adaption, exercise, and rest phase. Firstly, the exercise intensity significantly affected heart rate and metabolic rate, whereas the thermal environment had no significant effect. The effect of the thermal environment on skin temperature, thermal sensation vote (TSV), and thermal comfort vote (TCV) was more pronounced than that of exercise intensity. Secondly, during exercise, the metabolic rate took 6–9 min to stabilise, and the psychological response lagged compared to the physiological response. Thermal sensation was closest to neutral at 15 °C, 5 °C, and −5 °C when walking at 3 km/h, 4.50 km/h, and 6 km/h, respectively. Thermal comfort vote (TCV) levels were greater for higher exercise intensities at −15 to 5 °C, lower for higher exercise intensities at 25–35 °C, and similar for varied exercise intensities at 15 °C. Finally, current thermal comfort guidelines underestimate the exercise metabolic rate by at least 9.7%. This study helps clarify the dynamic changes and influence factors of thermal responses during exercise and provides a reference for future research on exercisers' thermal responses. • The required time for the metabolic rate to stabilise during exercise is 6–9 min. • Noticeable lag in the psychological response in all thermal environment conditions. • Thermal comfort level is highest when thermal sensation is slightly warm. • Metabolic rate is influenced more by exercise intensity than thermal environment. • Current thermal comfort standards underestimate exercise metabolic rate parameters. [ABSTRACT FROM AUTHOR]

Overcooling leads to unnecessary energy wastes and low thermal satisfaction rate. This study investigates the magnitude and energy impact of overcooling in a sub-tropical university campus. We deployed an environmental sensing network with 577 temperature sensors across the campus, collecting data every 30 min for 2 years. We derived the suitable temperature set-point using heat balance model and adaptive comfort model. We compared the actual temperature measurements with the set-point recommended by thermal comfort theories and standards in different jurisdiction. We found the indoor temperature measured in the campus buildings are averagely 2.5 °C lower than the comfort temperature recommended by the heat balance and adaptive comfort theories. The magnitude of overcooling are inhomogeneous: offices and interiors thermal zones suffer more from overcooling compared with other functional spaces and exterior thermal zones. And overcooling is more severe in the morning and during working days. Next, we use building energy simulation engine EnergyPlus to quantify the energy impact of overcooling. The simulation results show that overcooling in the campus lead to 34% more annual cooling energy consumption and 20% higher peak cooling load. Considering the increasing demand for space cooling due to global warming, mitigating overcooling provides a non-negligible opportunity to reduce cooling energy consumption and associated carbon emissions without compromising comfort. • We quantify the magnitude and energy impact of overcooling in a subtropical campus. • 577 temperature sensors were deployed across the campus, collecting data for 2 years. • The indoor temperature are averagely 2.5 °C lower than the recommended comfort temperature. • Overcooling leads to 34% more cooling energy consumption and 20% higher peak load. [ABSTRACT FROM AUTHOR]

Regulating landscape configuration (building, greenery, and water bodies) is a commonly accepted mitigation strategy for responding to the rapidly deteriorating urban thermal environment. Studies on urban plazas' thermal comfort, particularly those focusing on winter and summer, are still lacking. It also needs to be determined how the strategies interact with one another. This paper used quantitative studies and regression analysis to uncover these gaps. By changing the landscape configuration using the Envi-met model, 15 remodeled schemes of a typical urban plaza were proposed. Thirty simulations and analysis results for thermal environment conditions (summer and winter) were provided. This study also preliminarily investigated the interaction mechanisms between mitigation strategies. The findings demonstrate that increasing the plaza's water and greenery areas can significantly improve the summertime thermal environment. Wintertime thermal comfort is negatively impacted when the growth of the water body is greater than 15%, and the development of the greenery is greater than 40%. When the building coverage is increased within 15%, there is a beneficial effect on both summer and winter thermal comfort. Meanwhile, an interaction can be observed between the three landscape factors' mitigating effects on PET. Our findings could help designers use appropriate configurations to maximize the impact of mitigation. • Use the distribution map to illustrate modification effect of a plaza. • The effects of landscape configuration are evaluated via remodeling in Envi-met. • Remodel schemes is based on linear parametric design. • The quantitative analysis proposes the adjustment interval. • Differences in the magnitude of PET changes uncovers the interaction mechanism. [ABSTRACT FROM AUTHOR]

People spend about one third of their lives sleeping. Sleep is essential for the recovery of the body from both physical and psychological fatigue suffered throughout the day, the refreshment of mind, and the restoration of energy for maintenance of bodily functions. Current thermal comfort theories and standards are mainly concerned with people in waking state. However, many problems regarding thermal environment are found within a few field surveys in bedrooms, pushing out the need to investigate thermal environment and thermal comfort for sleeping people. In this paper, the questions concerning the measurement and evaluation of human sleep quality, the correlation between thermal regulation system and sleep regulation, and the characteristics of night-time space cooling load etc. are answered. The evidences illustrating the effects of thermal parameters on human sleep quality are also provided, in an attempt to shed light on the thermal comfort requirements of sleeping people. [ABSTRACT FROM AUTHOR]

The use of green roofs is an important method for mitigating heating of urban rooftop environments. Our study aimed to demonstrate the mitigation of thermal effects on a hot rooftop during summer by a hydroponic system in which rice was grown. The system was installed on the top of a commercial building in the large city of Osaka, Japan; the roof was divided into two areas, one bare, the other covered by the hydroponic system. In both areas, we measured thermal factors, such as air temperature, rooftop surface temperature, and conductive heat flux; from the data we calculated three thermal mitigation indices. We also propose normalized types of mitigation indices. Mitigation effects on the thermal environment by the hydroponic system could be well estimated from ambient air temperature and solar radiation; the effects were better explained by solar radiation than by ambient air temperature. The results indicate that during the hot season, the system's mitigation effects on the thermal environment can be predicted from solar radiation level, and the normalized mitigation index is an appropriate index for estimating the cooling effect. Our results suggest that the hydroponic system might affect the energy flow in two ways: the proportions of sensible heat flux and latent heat flux are mainly affected by evaporative cooling and the portion of conductive heat flux is mainly affected by radiation shielding. [ABSTRACT FROM AUTHOR]

A field survey was performed using questionnaires and physical measurements to investigate the thermal environment characteristics of typical transition spaces in residential buildings for the elderly and their impacts on the elderly's thermal adaptation. Forty-two buildings in 17 elderly care facilities in the Shanghai area were investigated. A model was constructed to predict the relationship of the temperature difference between the transition space and indoor environments, considering the indoor thermal satisfaction of the elderly dwelling in Shanghai's elderly care facilities. The elderly's indoor thermal satisfaction improved the most when the difference in temperature between the transition space and indoor environment was 6 °C and 2 °C in the winter and summer, respectively. Given the thermal satisfaction and self-assessed health of the elderly, the ideal model for designing a transition space in an elderly care facility is to utilize a semi-open external corridor with the temperature/humidity constantly increasing/decreasing from outdoors, transition space, and to indoors. A transition space assists the elderly in temperature adaptation through activities such as sunbathing and exercising. As a result, thermal conditions of aged-friendly care facilities should be designed and spatially composed to fulfil the needs of the elderly inhabitants. The use of an appropriate spatial thermal distribution within these environments can direct the elderly's daily behavior, improve their physical and mental health, and provide a scientific basis for planning and designing senior living communities. • A field survey was performed in residential buildings for the elderly. • Thermal environment characteristics in the transition spaces were investigated. • Space with a temperature buffer gradient had highest thermal satisfaction. • Transition spaces provide important areas for the elderly to thermally adapt. [ABSTRACT FROM AUTHOR]