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2.
Medicine (Baltimore) ; 103(21): e38293, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38787987

RESUMO

Metabolic rate has been used in thermophysiological models for predicting the thermal response of humans. However, only a few studies have investigated the association between an individual's trait-like thermal sensitivity and resting energy expenditure (REE), which resulted in inconsistent results. This study aimed to explore the association between REE and perceived thermal sensitivity. The REE of healthy adults was measured using an indirect calorimeter, and perceived thermal intolerance and sensation in the body were evaluated using a self-administered questionnaire. In total, 1567 individuals were included in the analysis (women = 68.9%, age = 41.1 ±â€…13.2 years, body mass index = 23.3 ±â€…3.3 kg/m2, REE = 1532.1 ±â€…362.4 kcal/d). More women had high cold intolerance (31.8%) than men (12.7%), and more men had high heat intolerance (23.6%) than women (16.1%). In contrast, more women experienced both cold (53.8%) and heat (40.6%) sensations in the body than men (cold, 29.1%; heat, 27.9%). After adjusting for age, fat-free mass, and fat mass, lower cold intolerance, higher heat intolerance, and heat sensation were associated with increased REE only in men (cold intolerance, P for trend = .001; heat intolerance, P for trend = .037; heat sensation, P = .046), whereas cold sensation was associated with decreased REE only in women (P = .023). These findings suggest a link between the perceived thermal sensitivity and REE levels in healthy individuals.


Assuntos
Calorimetria Indireta , Metabolismo Energético , Humanos , Feminino , Masculino , Adulto , Estudos Transversais , Pessoa de Meia-Idade , Metabolismo Energético/fisiologia , Sensação Térmica/fisiologia , Metabolismo Basal/fisiologia , Fatores Sexuais , Temperatura Alta/efeitos adversos , Temperatura Baixa , Índice de Massa Corporal
3.
Int J Biometeorol ; 68(5): 949-963, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38374295

RESUMO

In this initial study of a research project, this paper seeks to understand the thermal conditions in the cities of Lisbon and Munich, specifically focusing on Urban Heat Island intensity and on thermal comfort using the Universal Thermal Climate Index modeling data at the Local Climate Zone scale. Based on these datasets, Munich has exhibited more unfavourable thermal conditions than Lisbon. In terms of UHII, both cities have shown that low, medium, and high rise compact urban areas and bare rock or paved areas have the highest values, while sparsely built areas have the lowest. These results differ from the UTCI, which indicates that in Lisbon and Munich, these sparsely built areas as well as areas with low plants and vegetation are the most uncomfortable. In Munich, the population was exposed to very strong heat stress, while Lisbon experienced strong heat stress conditions. Conversely, low, medium, and high rise compact urban areas and densely wooded areas in Munich, and scattered trees areas and large low-rise urban areas in Lisbon, have demonstrated the lowest monthly mean and average maximum values. These results will be further explored in future studies in the city of Lisbon and cross-checked with data obtained from roving missions. This will enable a more detailed temporal and local analysis.


Assuntos
Cidades , Mudança Climática , Microclima , Humanos , Alemanha , Portugal , Modelos Teóricos , Sensação Térmica , Temperatura Alta
4.
Ergonomics ; 67(2): 207-224, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37272347

RESUMO

This paper introduces the equivalent contact temperature (ECT) model for local thermal comfort assessment in contact areas for non-uniform environmental conditions. It aims to complete the comfort evaluation scheme of the equivalent temperature approach included in ISO 14505-2 by the contact areas back and buttocks that are currently neglected in the standard. For the assessment of local and overall thermal comfort of seated persons, these contact areas are of great importance, especially if exposed to personal comfort systems. Person-oriented climatization systems, such as seat heating and ventilation, are much more energy efficient than conventional HVAC systems and allow to incorporate the human individual into the system's control loop. The ECT-approach is formally defined, analytically as well as mathematically derived and validated by a subject study. The results of the subject study (air temperature of 26 °C and 29 °C) confirm the cooling effect due to the seat ventilation and show fundamental correlations between ECTs and body part specific mean thermal votes for buttocks and back.Practitioner summary:The equivalent contact temperature model for local thermal comfort assessment in contact areas for non-uniform environmental conditions is formally defined, analytically as well as mathematically derived and validated by a subject study. It completes the existing equivalent temperature comfort scheme by both contact areas back a nd buttocks to improve thermal comfort assessment.


Assuntos
Temperatura Baixa , Sensação Térmica , Humanos , Temperatura , Temperatura Cutânea , Ventilação
5.
Sci Total Environ ; 858(Pt 1): 159729, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36309253

RESUMO

Constant urban growth exacerbates the demand for residential, commercial and traffic areas, leading to progressive surface sealing and urban densification. With climate change altering precipitation and temperature patterns worldwide, cities are exposed to multiple risks, demanding holistic and anticipatory urban planning strategies and adaptive measures that are multi-beneficial. Sustainable urban planning requires comprehensive tools that account for different aspects and boundary conditions and are capable of mapping and assessing crucial processes of land-atmosphere interactions and the impacts of adaptation measures on the urban climate system. Here, we combine Computational Fluid Dynamics (CFD) and Geographic Information System (GIS) capabilities to refine an existing 2D urban micro- and bioclimatic modelling approach. In particular, we account for the vertical and horizontal variability in wind speed and air temperature patterns in the urban canopy layer. Our results highlight the importance of variability of these patterns in analysing urban heat development, intensity and thermal comfort at multiple heights from the ground surface. Neglecting vertical and horizontal variability, non-integrated CFD modelling underestimates mean land surface temperature by 7.8 °C and the Universal Thermal Climate Index by 6.9 °C compared to CFD-integrated modelling. Due to the strong implications of wind and air temperature patterns on the relationship between surface temperature and human thermal comfort, we urge caution when relying on studies solely based on surface temperatures for urban heat assessment and hot spot analysis as this could lead to misinterpretations of hot and cool spots in cities and, thus, mask the anticipated effects of adaptation measures. The integrated CFD-GIS modelling approach, which we demonstrate, improves urban climate studies and supports more comprehensive assessments of urban heat and human thermal comfort to sustainably develop resilient cities.


Assuntos
Sistemas de Informação Geográfica , Temperatura Alta , Humanos , Sensação Térmica , Hidrodinâmica , Vento , Cidades , Temperatura
6.
Artigo em Inglês | MEDLINE | ID: mdl-35565078

RESUMO

Research on urban thermal environments based on thermal comfort can help formulate effective measures to improve urban thermal and human settlement environments, which is of great significance for improving urban quality, urban climate change adaptation, and sustainable development. Taking 344 municipal administrative districts in China as study areas, the Universal Thermal Climate Index (UTCI) of each city in the last 20 years was calculated to evaluate thermal comfort. We then analyzed the thermal comfort and spatiotemporal heterogeneity of each city during a typical heat wave. Finally, the driving forces of the potential socioeconomic, natural, and landscape factors influencing thermal comfort were analyzed using geographic detectors. The results show that the thermal comfort index had similar spatial patterns and differentiation characteristics in different years, and the interannual variation was not obvious. Cities in the typical heat wave period were mainly distributed in East and Northwest China. The driving factor in the contribution rate of the same index in different years was basically the same and was not affected by the change in years, and the highest contribution rate was the natural factor.


Assuntos
Aclimatação , Sensação Térmica , China , Cidades , Humanos , Desenvolvimento Sustentável
7.
Sensors (Basel) ; 22(5)2022 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-35270974

RESUMO

The MoBiMet (Mobile Biometeorology System) is a low-cost device for thermal comfort monitoring, designed for long-term deployment in indoor or semi-outdoor occupational contexts. It measures air temperature, humidity, globe temperature, brightness temperature, light intensity, and wind, and is capable of calculating thermal indices (e.g., physiologically equivalent temperature (PET)) on site. It visualizes its data on an integrated display and sends them continuously to a server, where web-based visualizations are available in real-time. Data from many MoBiMets deployed in real occupational settings were used to demonstrate their suitability for large-scale and continued monitoring of thermal comfort in various contexts (industrial, commercial, offices, agricultural). This article describes the design and the performance of the MoBiMet. Alternative methods to determine mean radiant temperature (Tmrt) using a light intensity sensor and a contactless infrared thermopile were tested next to a custom-made black globe thermometer. Performance was assessed by comparing the MoBiMet to an independent mid-cost thermal comfort sensor. It was demonstrated that networked MoBiMets can detect differences of thermal comfort at different workplaces within the same building, and between workplaces in different companies in the same city. The MoBiMets can capture spatial and temporal differences of thermal comfort over the diurnal cycle, as demonstrated in offices with different stories and with different solar irradiances in a single high-rise building. The strongest sustained heat stress was recorded at industrial workplaces with heavy machinery.


Assuntos
Sensação Térmica , Vento , Cidades , Comunicação , Umidade
8.
Sci Total Environ ; 808: 152079, 2022 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-34856261

RESUMO

Thermal comfort and environmental health in scenic open spaces, a communication bridge between tourists and their environment, are prerequisites for tourism activities. In this study, scenic open spaces in an urban area of Xi'an, China were selected. Thermal perception (thermal sensation, comfort and acceptability) of residents and tourists were investigated through meteorological measurement and questionnaire survey. Physiological equivalent temperature (PET) was used to determine thermal benchmarks of all visitors to the site. Variables that influence individual thermal perception assessment (physical, individual, society and psychology) were measured and compared. Finally, a series of strategies and suggestions were proposed based on meteorological characteristics and influencing factors of thermal perception from perspectives of designers and scenic spot managers. Results show that: 1) Neutral PET (NPET) of respondents were 17.3 °C (residents) and 15.5 °C (tourists). Neutral PET ranges (NPETR) were 8.9-25.8 °C (residents) and 7.2-23.8 °C (tourists). Preferred PET values were 20.1 °C (residents) and 19.7 °C (tourists). Thermal acceptability ranges (TAR) were 6.3-37.8 °C (residents) and 0.5-39.9 °C (tourists). 2) In winter, physical factors were primary influencers of residents' thermal perception, followed by social factors, while tourists' thermal perception was mainly influenced by physical factors. In spring, physical factors were still the primary influencers for residents, followed by individual factors. Physical factors were also dominant for tourists, followed by psychological. In summer, physical factors were the major influencing factors for residents and tourists' thermal perceptions.


Assuntos
Temperatura Baixa , Sensação Térmica , China , Humanos , Estações do Ano , Temperatura , Turismo
9.
Sci Rep ; 11(1): 23684, 2021 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-34880349

RESUMO

Growth in energy use for indoor cooling tripled between 1990 and 2016 to outpace any other end use in buildings. Part of this energy demand is wasted on excessive cooling of offices, a practice known as overcooling. Overcooling has been attributed to poorly designed or managed air-conditioning systems with thermostats that are often set below recommended comfort temperatures. Prior research has reported lower thermal comfort for women in office buildings, but there is insufficient evidence to explain the reasons for this disparity. We use two large and independent datasets from US buildings to show that office temperatures are less comfortable for women largely due to overcooling. Survey responses show that uncomfortable temperatures are more likely to be cold than hot regardless of season. Crowdsourced data suggests that overcooling is a common problem in warm weather in offices across the US. The associated impacts of this pervasive overcooling on well-being and performance are borne predominantly by women. The problem is likely to increase in the future due to growing demand for cooling in increasingly extreme climates. There is a need to rethink the approach to air-conditioning office buildings in light of this gender inequity caused by overcooling.


Assuntos
Temperatura , Sensação Térmica , Ar Condicionado , Feminino , Humanos , Masculino , Fatores Sexuais , Mídias Sociais , Inquéritos e Questionários
10.
Sci Total Environ ; 795: 148663, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34237537

RESUMO

In recent years, walkability is increasingly integrated into sustainability strategies, considering its many health and environmental benefits. Besides, thermal comfort also has been progressively promoted as a critical measure for pedestrian comfort and wellbeing. Despite the relevance of the two concepts, few studies combined them in a comprehensive model. This study considers thermal comfort in assessing walkability by developing a new measurement tool, the Street Walkability and Thermal Comfort Index (SWTCI), which focuses on comfort facilities and Physiological Equivalent Temperature (PET), at the street scale. The applied point system method requires combining a questionnaire survey, observations, and in situ measurements (air temperature, wind velocity, and relative humidity). The questionnaire survey (330 responders) measured 21 street design indicators' importance, using a five-point Likert scale ranging from 1 (least important) to 5 (very important). The observation technique seeks to evaluate every pedestrian comfort indicator score (Sis). The in situ measurements permit Envi-met's calibrated data validation and getting the mean radian temperature (Tmrt). Those were considered in the PET's calculation using Rayman software. Three distinct streets have been chosen in Annaba city, Algeria, within the Mediterranean climate (Csa). The results show that the SWTCI achieves its highest score on the three streets when the thermal perception is neutral (20 < PET <26), and its lowest score, with a warm thermal sensation (28 < PET < 31). Despite the divergence in PET values, the highest score of SWTCI was 33%, reflecting a low comfort quality and minimal pedestrian facilities. Applying the SWTCI method can transform uncomfortable streets into an ideal walkable and pleasant path by finding the problems and proposing improvements.


Assuntos
Pedestres , Sensação Térmica , Cidades , Humanos , Temperatura , Vento
11.
Sci Total Environ ; 790: 147941, 2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34098272

RESUMO

The assessment of outdoor comfort can provide valuable insights into the quality of urban public spaces. Rational indices based on the heat-balance model have been extensively used for assessing thermal comfort in various outdoor environments for a long time. However, a growing body of literature is arguing the theoretical limitations of rational indices, including the lack of contextual considerations and the non-consideration of the active role of human being. Furthermore, the well-documented inconsistency in previous investigations suggests individuals' heterogeneous thermal expectations, preferences and adaptations typically depend on person-related and place-related contexts. Nevertheless, the study of heterogeneity in comfort assessment remains fragmentary. In an attempt to incorporate heterogeneity into a comprehensive conceptual framework of outdoor comfort, this study develops a latent class path model based on empirical data of 701 respondents from Eindhoven, the Netherlands. We identified two latent classes associated with different causal structures underlying the assessment of outdoor comfort. Meanwhile, the membership of latent classes is identified based on respondents' socio-demographic and behavioral covariates. The results show that, with respect to the influence on comfort assessment, the exogenous and endogenous variables are varying in effectiveness and strength between the two latent classes. Latent class 1 assesses the outdoor comfort mainly based on thermal sensation and expectations of thermal and wind conditions, whereas latent class 2 comprehensively considered both thermal and non-thermal influences, especially, the psychological acceptability and need satisfaction of outdoor activity. Our findings suggest that, in addition to the expanded framework of outdoor comfort study, understanding the heterogeneity in respondents' comfort perception is needed to comprehensively address the approaches to archive the comfortable urban public spaces in design, planning and management practices.


Assuntos
Meio Ambiente , Sensação Térmica , Temperatura Alta , Humanos , Países Baixos , Vento
12.
Int J Biometeorol ; 65(7): 1177-1187, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33656645

RESUMO

Brazil is the country with the highest social inequality in South America. This socioeconomic disparity reflects not only on the families' income but also on their spatial localization in the city, as well as on the urban design. These urban environments can alter the urban microclimate, and consequently, interfere in dwellers' thermal comfort. This research investigated the relationship between socio-spatial inequalities and thermal comfort in two different Local Climate Zones (LCZ) using a combination of measurement and modeling. Air temperature (Tair) was obtained by on-site measurements in compact high-rise (LCZ1) and compact low-rise buildings (LCZ3) and Mean radiant temperature (Tmrt) was simulated using SOlar and LongWave Environmental Irradiance Geometry (SOLWEIG). The results indicated that in LCZ1 seafront-localized buildings, in which residents have a higher income, the temperature remains in a range classified as comfortable, mainly due to shading and sea breeze. On the other hand, LCZ3, located in the periphery of the city, in which the low-income population is concentrated and is marked by a precariousness urban environment, presented a higher air temperature and Tmrt values, exposing the dwellers to heat stress throughout the year, especially during the summer season. These observations suggested that public and private actions tend to promote better urban designs in areas with a higher concentration of income. Public reforms aimed at improving the urban environment and promoting thermal comfort should be a priority for the warmest LCZ, where the poorest residents live. Public agents should rethink the distribution of environmental resources to promote equitable urban spaces.


Assuntos
Clima , Sensação Térmica , Brasil , Cidades , Humanos , Microclima , Temperatura
13.
Br J Sports Med ; 55(15): 825-830, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32467149

RESUMO

BACKGROUND: The Wet-Bulb Globe Temperature (WBGT) index is a common tool to screen for heat stress for sporting events. However, the index has a number of limitations. Rational indices, such as the physiological equivalent temperature (PET) and Universal Thermal Climate Index (UTCI), are potential alternatives. AIM: To identify the thermal index that best predicts ambulance-required assistances and collapses during a city half marathon. METHODS: Eight years (2010-2017) of meteorological and ambulance transport data, including medical records, from Gothenburg's half-marathon were used to analyse associations between WBGT, PET and UTCI and the rates of ambulance-required assistances and collapses. All associations were evaluated by Monte-Carlo simulations and leave-one-out-cross-validation. RESULTS: The PET index showed the strongest correlation with both the rate of ambulance-required assistances (R2=0.72, p=0.008) and collapses (R2=0.71, p=0.008), followed by the UTCI (R2=0.64, p=0.017; R2=0.64, p=0.017) whereas the WBGT index showed substantially poorer correlations (R2=0.56, p=0.031; R2=0.56, p=0.033). PET stages of stress, match the rates of collapses better that the WBGT flag colour warning. Compared with the PET, the WBGT underestimates heat stress, especially at high radiant heat load. The rate of collapses increases with increasing heat stress; large increase from the day before the race seems to have an impact of the rate of collapses. CONCLUSION: We contend that the PET is a better predictor of collapses during a half marathon than the WBGT. We call for further investigation of PET as a screening tool alongside WBGT.


Assuntos
Ar , Ambulâncias/estatística & dados numéricos , Temperatura Corporal/fisiologia , Exaustão por Calor/epidemiologia , Corrida/estatística & dados numéricos , Termografia/métodos , Adolescente , Adulto , Distribuição por Idade , Idoso , Regulação da Temperatura Corporal , Intervalos de Confiança , Feminino , Exaustão por Calor/diagnóstico , Transtornos de Estresse por Calor , Resposta ao Choque Térmico , Humanos , Umidade , Modelos Lineares , Masculino , Corrida de Maratona , Pessoa de Meia-Idade , Método de Monte Carlo , Risco , Corrida/fisiologia , Distribuição por Sexo , Temperatura Cutânea/fisiologia , Luz Solar , Suécia/epidemiologia , Termografia/instrumentação , Sensação Térmica , Fatores de Tempo , Vento , Adulto Jovem
14.
Int J Biometeorol ; 65(9): 1463-1472, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32206912

RESUMO

Both global climate change and urbanization trends will demand adaptation measures in cities. Large agglomerations and impacts on landscape and natural environments due to city growth will require guided densification schemes in urban areas, particularly in developing countries. Human biometeorological indices such as the Universal Thermal Climate Index (UTCI) could guide this process, as they provide a clear account of expected effects on thermal sensation from a given change in outdoor settings. However, an earlier step should optimally include an adequacy test of suggested comfort and thermal stress ranges with calibration procedures based on surveys with the target population. This paper compares obtained thermal comfort ranges for three different locations in Brazil: Belo Horizonte, 20° S, Aw climate type; Curitiba, 25.5° S, Cfb subtropical climate, both locations in elevation (above 900 m a.s.l.); and Pelotas, at sea level, latitude 32° S, with a Cfa climate type. In each city, a set of outdoor comfort field campaigns has been carried out according to similar procedures, covering a wide range of climatic conditions over different seasons of the year. Obtained results indicate a variation of neutral temperatures up to 3 °C (UTCI units) as a possible latitude and local climate effect between the southern locations relative to the northernmost location. Low UTCI values were found in the two subtropical locations for the lower threshold of the thermal comfort band as compared with the original threshold. A possible explanation for that is a longer exposure to cold conditions as buildings are seldom provided with heating systems.


Assuntos
Sensação Térmica , Brasil , Cidades , Humanos , Estações do Ano , Temperatura
15.
Int J Biometeorol ; 65(9): 1473-1483, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32383024

RESUMO

The impact of climatic conditions on human beings can be assessed using bioclimatic indices. In this study, the Universal Thermal Climate Index (UTCI) was applied to assess the bioclimate in Russia. Seasonal features, region-specific features, and extreme values of the UTCI were considered in the climatic conditions of 2001-2015. The UTCI values for the datasets were obtained in the daytime (at 15:00) and at night (at 03:00) in the territory of Russia using the software package BioKlima 2.6. Daily current meteorological data were used as input for the calculations, including air temperature, relative humidity, wind speed, and total cloud cover. It was established that all categories of cold stress and almost all categories of heat stress are observed in Russia, but the cold stress conditions prevail. In winter, cold stress of various categories predominated over almost the entire territory in both the daytime and at night. In summer, conditions of no heat stress and comfort were observed in the largest part of Russia, while conditions of moderate heat stress were noted in the south of the European part during daytime hours. Extreme cold stress occurred over almost the entire territory of Russia with the exception of the west border, the foothills of the Caucasus and the coasts of the Black and Caspian Seas. In the largest part of the country, the maximum UTCI values for the study period corresponded to slight and strong heat stress.


Assuntos
Clima , Transtornos de Estresse por Calor , Humanos , Federação Russa , Temperatura , Sensação Térmica , Vento
16.
Artigo em Inglês | MEDLINE | ID: mdl-32971989

RESUMO

The temperature of the indoor environment is important for health and wellbeing, especially at the extremes of age. The study aim was to understand the relationship between self-reported thermal sensation and extremity skin temperature in care home residents with and without dementia. The Abbreviated Mental Test (AMT) was used to discriminate residents to two categories, those with, and those without, dementia. After residents settled and further explanation of the study given (approximately 15 min), measurements included: tympanic membrane temperature, thermal sensation rating and infrared thermal mapping of non-dominant hand and forearm. Sixty-nine afebrile adults (60-101 years of age) were studied in groups of two to five, in mean ambient temperatures of 21.4-26.6 °C (median 23.6 °C). Significant differences were observed between groups; thermal sensation rating (p = 0.02), tympanic temperature (p = 0.01), fingertip skin temperature (p = 0.01) and temperature gradients; fingertip-wrist p = 0.001 and fingertip-distal forearm, p = 0.001. Residents with dementia were in significantly lower air temperatures (p = 0.001). Although equal numbers of residents per group rated the environment as 'neutral' (comfortable), resident ratings for 'cool/cold' were more frequent amongst those with dementia compared with no dementia. In parallel, extremity (hand) thermograms revealed visual temperature demarcation, variously across fingertip, wrist, and forearm commensurate with peripheral vasoconstriction. Infrared thermography provided a quantitative and qualitative method to measure and observe hand skin temperature across multiple regions of interest alongside thermal sensation self-report. As an imaging modality, infrared thermography has potential as an additional assessment technology with clinical utility to identify vulnerable residents who may be unable to communicate verbally, or reliably, their satisfaction with indoor environmental conditions.


Assuntos
Demência , Termografia , Sensação Térmica , Idoso , Idoso de 80 Anos ou mais , Demência/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Temperatura Cutânea , Temperatura
17.
Int J Biometeorol ; 64(8): 1355-1366, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32363522

RESUMO

Many children growing up in cities are spending less time outdoors to escape the heat. This is contributing to childhood obesity and the prospect of a range of diseases in adulthood. When landscape architects and urban designers use a human thermal comfort model to test their designs for children's comfort, they would have to use a model essentially designed to simulate healthy adults. Yet there are many differences between the body of a child and an adult. The aim of this paper was to modify the thermal comfort model COMFA into a children's energy budget model through the consideration of the heat exchange of a child. The energy budget of a child can be up to 21 W/m2 higher than adults in hot summertime conditions, and 26 W/m2 lower in cold conditions. The model was validated through field studies of 65 children (32 boys and 33 girls) aged from 7-12 years old in 9 days from March to June in 2019, in 68 different microclimates ranging from cool to hot. A 5-point thermal comfort scale of energy budget for children was created using multinomial logistic regression, which revealed that children have a different range of thermal acceptability than adults. The frequency distribution of the actual thermal sensation and the predicted thermal comfort was improved using the new scale. The actual thermal sensation responses from children and the predicted thermal sensation using the model was determined to be positively significantly related. The accuracy of the model was 93.26%. This study has provided an effective children's energy budget model to predict children's thermal comfort. Its application can contribute to the design of thermally comfortable children's outdoor play areas by landscape architects and urban designers.


Assuntos
Microclima , Sensação Térmica , Adulto , Criança , Cidades , Feminino , Temperatura Alta , Humanos , Masculino
18.
J Environ Manage ; 267: 110655, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32421680

RESUMO

Assessing the thermal comfort of the car in a hot and humid climate is crucial as it may have adverse health implications. In the current study, different models of car were used to conduct real-time monitoring of temperature and relative humidity (RH %) inside the car cabin to assess the thermal comfort of a virtual occupant. The temperature in car cabins during the monitoring period ranged between 26.7 and 64.9 °C while the range of RH was 8.3-60.4%. Data from meteorological stations were also collected to develop a scenario of thermal comfort of occupants outside the car in standing position. The PMV range as per ASHRAE 55-2017 guidelines for ambient conditions was 3.24-7.41, the car front was 8.36-11.87, and the car back was 11.5-18.04. The thermal comfort sensation was found to be hot in all instances and followed category IV of EN15251 guidelines. PMV was observed to be worst for Sedan for both front and back as per both ASHRAE 55-2015 and EN12521 guidelines. The PPD was observed to be 100% in all cases, showing dissatisfaction for all car models. The concentration of CO2 and CO ranged between 113-1127 ppm and 0-3.9 ppm, respectively, for the front of the car. The results were also compared with the threshold values of thermal comfort parameters according to ISHRAE Standard 10,001:2016 and found to be acceptable. Climate change is leading to extremes in temperature, this may impact the thermal comfort of the car occupants to a great extent due to the heating of the car cabins, which act as a closed microenvironment. Hence, the current study urges to formulate guidelines for car design based on thermal comfort and developing a sensor to indicate thermal comfort for occupants to avoid adverse health impacts in the hot climate.


Assuntos
Calor Extremo , Clima Tropical , Automóveis , Calefação , Temperatura , Sensação Térmica
19.
Sci Total Environ ; 721: 137741, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32179347

RESUMO

Extreme heat and associated health risks increasingly become threats to urban populations, especially in developing countries of the tropics. Although human thermal exposure in cities has been studied across the globe, current narratives insufficiently discuss mixed-used spaces, informal economic activity settings, and informal settlements. This study assessed outdoor human thermal comfort in the tropical city of Kolkata, India where uncomfortable hot and humid climatic conditions prevail year-round. Thermal Comfort Perception Surveys (TCPS) and biometeorological observations were conducted during summer and winter in three microentrepreneurial neighborhoods (Kumartuli, Boipara, and Mallickghat). A one-way ANOVA was performed to investigate the variance in Physiologically Equivalent Temperature (PET) values of 318 survey samples across neighborhoods. Through multiple linear regression and ANCOVA, significant relationships were established between various climatic and non-climatic parameters. No respondent reported a neutral thermal sensation during the summer. Annual neutral PET across neighborhoods was 23.6 °C with a neutral PET range of 19.5 °C to 27.6 °C. Annual neutral PET was 22.7 °C and 26.5 °C in Mallickghat and Boipara, respectively. Respondents in Boipara were more sensitive towards warmer sensation than in Mallickghat. Even in the winter, people reported warmer sensation votes. PET was a better predictor of the mean Thermal Sensation Vote (mTSV) compared to air temperature. In a few cases, acclimatization and expectations improved thermal comfort. Results can be useful in formulating strategies towards improving outdoor microclimate and heat health in tropical cities.


Assuntos
Microclima , Sensação Térmica , Cidades , Humanos , Índia , Estações do Ano
20.
Int J Occup Saf Ergon ; 26(1): 46-54, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29583088

RESUMO

A pair of lightweight electrically heated gloves (EHG) with smart temperature control function was developed. To evaluate the thermoregulation properties of the EHG, human trials were conducted in a climate chamber (2.5 °C, 60% RH). The changes in skin temperature at all fingers and the opisthenar, and the subjective thermal sensation were recorded over 60 min. The effects of two air velocities (i.e., 0.17 and 0.50 m/s) on the cold protective performance of the EHG in scenarios of heating and control were also investigated. For heating scenarios, skin temperature and thermal sensation at all fingers and the opisthenar were found significantly higher than those in control conditions. Moreover, the air velocity at 0.50 m/s greatly reduced the cold protective performance of the gloves. The research findings can be applied to improve thermal comfort and extend working times for persons in cold environments.


Assuntos
Luvas Protetoras , Calefação/métodos , Termorreceptores , Sensação Térmica , Feminino , Humanos , Masculino , Temperatura Cutânea , Fatores de Tempo , Adulto Jovem
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