Assessment Of Outdoor Thermal Comfort Research Articles

Exploring the effects of landscape interventions on outdoor thermal comfort using digital simulation

Abstract The assessment of outdoor thermal comfort plays an important role in design decisions and encourages better planning and development of outdoor environments. This study explores the potential effects of landscape interventions on outdoor thermal comfort, testing two thermal comfort indicators on a selected hospitality development. Results are crucial factors to consider as the success of hospitality developments and its outdoor spaces are dependent on how visitors perceive and interact with them. Digital simulations were conducted using Rhinoceros software and the Grasshopper tool to produce heat maps. For the purpose of the study, two sets of simulations were developed to examine changes in the Universal Thermal Climate Index (UTCI) and Incident Radiation of the site – a) buildings alone and b) with landscape elements. As a result, UTCI with landscape intervention decreased by 2°C while Incident Radiation is significantly lower throughout spaces provided with shading elements. Results of UTCI simulations still deliver strong heat stress to occupants, while Incident Radiation has considerably improved with landscape interventions. The provision of shading elements helped lessen solar radiation penetrating the site, thus improving the thermal comfort of users. Wind velocity showed minimal effects on perceived heat based on the UTCI assessment scale. Nonetheless, improvement in the planning and orientation of buildings and strategic provision of demountable sun shading elements in future developments are recommended to allow better air circulation.

Assessment of universal thermal climate index (UTCI) using the WRF-UCM model over a metropolitan city in India.

Rapid urbanization increases urban air temperature, considerably affecting health, comfort, and the quality of life in urban spaces. The accurate assessment of outdoor thermal comfort is crucial for urban health. In the present study, a high-resolution mesoscale model coupled with a layer Urban Canopy Model (WRF-UCM) is implemented over the city of Hyderabad (17.3850° N, 78.4867° E) to simulate urban meteorological conditions during the summer and winter period of 2009 and 2019. The universal thermal climate index (UTCI) has been estimated using the model-derived atmospheric variables and a human biometeorology parameter to assess the linkages between the outdoor environment and thermal comfort. Results revealed that during summer, the city experiences nearly 50h of very strong thermal stress, whereas about 120h of slight cold stress are experienced during winter. The urban area in Hyderabad expanded from 5 to 15% during the study period, leading to a 2.5℃ (2.8 ℃) increase in land surface temperature, and a 1.2 (1.9 ℃) rise in air temperature at 2m height and 1.5 (2.5 ℃) UTCI during summer (winter) time. The analysis reveals that the maximum UTCI values were noticed over built-up areas compared to other land classes during daytime and nighttime. The results derived from the present study have shown that the performance of WRF-UCM-derived UTCI reasonably portrayed the significant impact of urbanization on thermal comfort over the city and provided useful insights with regard to urban comfort and welfare.

Advancing Urban Microclimate Monitoring: The Development of an Environmental Data Measurement Station Using a Low-Tech Approach

Researchers studying urban climates aim to understand phenomena like urban heat islands (UHIs), which describe temperature differences between urban and rural areas. However, studies often lack numerous measurement points and frequently overlook parameters like radiation and air velocity due to the high cost of precision instrumentation. This results in data with a low resolution, particularly in tropical cities where official weather stations are scarce. This research introduces a new, low-tech tool for district-level outdoor thermal comfort assessment and UHI characterization to address these challenges. The automated weather station employs sensors to measure temperature, humidity, wind speed, solar radiation, and globe temperature. The paper details these sensors’ rigorous selection and validation process, followed by a description of the sensor assembly, data acquisition chain, and network operation mechanisms. Calibration outcomes in laboratory and in situ environments highlight the station’s reliability, even in tropical conditions. In conclusion, this weather station offers a cost-effective solution to gathering high-resolution data in urban areas, enabling an improved understanding of the UHI phenomenon and the refinement of urban microclimate numerical models.

A preliminary study of multidimensional semantic evaluation of outdoor thermal comfort in Chinese

Traditional method to evaluate outdoor thermal comfort which used indicators (UTCI, PET, SET, etc.) has its limitations. Firstly, emotional factors are not included in the assessment, and secondly, the results lead to less accessibility, and it is difficult for non-experts to understand.Due to the above reasons, some scholars have investigated how to evaluate outdoor thermal comfort by ‘English vocabulary’, and there is still a gap in exploring the multidimensional semantic assessment of outdoor thermal comfort by using ‘Chinese vocabulary’. This paper established a ‘Chinese vocabulary’ thesaurus for outdoor thermal comfort evaluation through online and on-site questionnaire survey including 63 words, and an outdoor experiment was carried out to validate the effectiveness of the thesaurus. The results showed a significant correlation between the 2-phases results, revealing the effectiveness of the multidimensional semantic Chinese thesaurus. PET value has a wide range when Thermal Comfort Vote (TCV) are the same, and the words people used to describe the thermal environment in 5 dimensions are very different. The results showed that it is necessary to evaluate the thermal environment by the way of multidimensional semantic, which could make up the short comings of the traditional way (thermal comfort indicators).The field validation experiment of this study was only carried out for 3 days in spring in Shenyang city, thus the result was highly influenced by the experiment conditions and has its limitations. This study could be a fundamental exploration of thermal comfort evaluation by semantic way in Chinese words.

Assessment of Outdoor Thermal Comfort in a Hot Summer Region of Europe

Heat waves are increasingly frequent in Europe, especially in South European countries during the summer season. The intensity and frequency of these heat waves have increased significantly in recent years. Spain, as one of the southern European countries most affected by these recurring heat waves, particularly experiences this phenomenon in touristic cities such as Cordoba. The aim of this study was to perform an experimental assessment of outdoor thermal comfort in a typical three-hour tourist walkable path of the historical center of Cordoba. The experimental study was carried out in the three-hour period of higher temperatures from 16:30 to 19:30 h CEST (UTC+2) on a normal summer day (6 July 2023), a day with a heat wave (28 June 2023) and a day with a higher heat intensity, called a super heat wave (10 August 2023). Environmental conditions such as a radiant temperature, ambient temperature, wet bulb temperature, air velocity and relative humidity were measured at three different heights corresponding to 0.1 (ankles), 0.7 (abdomen) and 1.7 (head) m. The results show extremely high levels of heat stress in all bioclimatic indices throughout the route. Cumulative heat stress ranged from “very hot” conditions at the beginning of the route to becoming “highly sweltering” at the end of the route. The average temperature excess over the thermal comfort threshold was very high and increased with the heat intensity. In addition, a correlation analysis was carried out between the bioclimatic indices studied, with the UTCI index standing out for its strong correlation with other thermal comfort indices. The findings emphasize the need for interventions to improve the urban environment and promote better outdoor thermal comfort for city dwellers through measures such as green infrastructure, UHI mitigation and increasing public awareness.

Remote Sensing-Based Outdoor Thermal Comfort Assessment in Local Climate Zones in the Rural-Urban Continuum of eThekwini Municipality, South Africa.

Due to the need to continuously monitor and understand the thermal environment and its socioeconomic implications, this study used remotely sensed data to analyze thermal comfort variation in LCZs, including along the rural to urban gradient of the eThekwini Municipality in KwaZulu-Natal province of South Africa. LCZs were mapped using multi-temporal and multi-spectral Landsat 8 and Landsat 9 data using the approach by World Urban Database and Access Portal Tools (WUDAPT), while thermal data were used to retrieve land surface temperatures (LSTs). Data for training classification of LCZs and accuracy assessment were digitized from GoogleEarth guided by knowledge gained and data collected during a field survey in March 2022 as well as pre-existing maps. LCZs were mapped using the random forest classifier in SAGA GIS software while a single channel algorithm based on band 10 was used to compute LST for different scenes. The LSTs were adjusted and further used to derive thermal comfort based on the Universal Thermal Comfort Index (UTCI) categories as an indicator for outdoor thermal comfort on the extremely low- and extremely high-temperature periods in the cool and hot seasons, respectively. LCZs were mapped with high accuracy (overall accuracy of 90.1% and kappa of 0.88) while inter-class separability was high (>1.5) for all LCZ pairs. Built-up LCZs dominate the eastern parts of the municipality, signifying the influence of the sea on development within the area. Average LST was coolest in the dense forest, open low-rise and water LCZs in the cool and hot seasons, respectively. The compact high-rise LCZ was the warmest in both the hot (36 °C) and the cool (23 °C) seasons. The sea sands were among coolest regions in both seasons due to their high water content, attributed to their high water table and close proximity to the ocean. There was no thermal stress during the cool season, while most areas recorded moderate to strong heat stress in the hot season. Some areas in the densely built-up LCZs recorded very strong heat stress in the hot season. The findings suggest that policies and strategies should enhance heat mitigation capacities in strong-heat-stress areas during the hot season. Municipal authorities and citizens must work together to build strategies to minimize temperature extremes and associated socioeconomic pressures. Urban development policies, plans and strategies should consider implications on the thermal environment as well as the value of conservation of LCZs with high-heat mitigation value such as dense forests and expansion of built-up LCZs with low-heat absorption levels such as open low-rise. The study was based mainly on remotely sensed temperatures with some ground data used to validate results, which may limit the assessment. Overall, the study provides insights towards achievement of global sustainable and climate-smart development targets.

Summer outdoor thermal comfort assessment in city squares—A case study of cold dry winter, hot summer climate zone

Human thermal perception varies with climate. The Dwa climate zone covers vast areas. Conducting outdoor thermal comfort (OTC) studies here would benefit energy efficiency and the economy. However, since OTC research methods are not standardized, different research methods hamper comparing studies in the Dwa climate. This paper aims to determine the summer OTC of typical Dalian squares in the Dwa climate. Dalian is located in the cold A zone (2A) of the China Building Climate Division. The thermal environment of three typical squares was field measured, and a questionnaire survey of the residents was conducted. 33.2 % of Dalian residents evaluated the thermal environment as neutral, and 39.3 % considered it comfortable. And psychological perception and physical perception were not the same. Multiple methods were used to calculate outdoor thermal benchmarks and calibrate thermal stress for three thermal indexes, SET*, PET, and UTCI. Furthermore, PET, with a prediction accuracy of 25.3 %, was determined to be the best indicator applicable to Dalian in the summer. Finally, a comparison of studies under the Dwa climate zone, including Tianjin and Harbin, reconfirmed the mobility of the human thermal zone. These findings are precious and can contribute significantly to ensuring the sustainability of the outdoor environment.

An Investigation of Outdoor Thermal Comfort Assessment for Elderly Individuals in a Field Study in Northeastern China

The harsh climate and the aging of urban populations have negatively impacted the quality of life of the elderly in severely cold regions. As a result, there is an urgent need to improve environment quality and accurately evaluate outdoor thermal comfort. However, existing studies have paid little attention to older adults living in severely cold climates. This paper aims to fill this gap by studying the elderly population in severely cold cities with high aging rates in China. By combining on-site testing, questionnaire surveys, CFD modeling, parametric computing, and statistical analysis, the study presents an adapted UTCI for elderly people, as well as multi-seasonal prediction models. The results (1) show that the neutral ranges of the UTCI are significantly affected by both climate zones and age groups. Older people are more tolerant to heat but more sensitive to cold. (2) The results also reveal the importance of factors such as air temperature, wind speed, solar radiation temperature, wind direction, relative humidity, and cloud cover in evaluating outdoor thermal comfort. (3) Multi-seasonal thermal comfort models based on neural networks were developed, and empirical studies verified that the model had the highest accuracy in the transitional season and the lowest accuracy in the winter season.

Assessment of Outdoor Thermal Comfort in Urban Public Space, during the Hottest Period in Annaba City, Algeria

In this study; the outdoor thermal comfort of the users of two urban plazas with different morphologies in Annaba city, Algeria, have been evaluated. First, field measurements of the microclimatic parameters took place; namely the air temperature and the relative humidity in the two urban plazas, during hot days. Then, these measurements were compared with the results of the numerical simulations carried out by ENVI-met software in order to validate the model. The outdoor thermal comfort was evaluated by microclimatic measurements as well as a questionnaire survey consisting of interviews during the measurement days. The main objective was to determine the neutral Physiological Equivalent Temperature (PET) and to examine the influence of urban microclimatic conditions on the subjective thermal perception of people, as well as to compare it with different indexes of thermal comfort. Hence, the aim was to compare the microclimatic parameters of the two plazas, with and without vegetation and to see their impact on the thermal comfort indices. The results show that there is a difference between the two morphologies. Moreover, vegetation and urban morphology influence the neutral values of the thermal comfort indices.

Assessment of Outdoor Thermal Comfort Using Landsat 8 Imageries with Machine Learning Tools over a Metropolitan City of India

Assessment of Outdoor Thermal Comfort Using Landsat 8 Imageries with Machine Learning Tools over a Metropolitan City of India

Effects of mask wearing duration and relative humidity on thermal perception in the summer outdoor built environment.

During the pandemic, face masks are one of the most significant self-protection necessities, but they also cause heat stress. By using the ERA5 (ECMWF Reanalysis 5th Generation) database and the local weather bureau data, the effect of mask wearing on outdoor thermal sensation has been investigated by a survey conducted in the hot summer and cold winter region of eastern China in the summer of 2020. Results show that wearing a face mask for a longer period result in a higher level of discomfort, and the primary source of discomfort is hot and stuffy feelings. The effect of relative humidity is crucial for mask wearers in warm-biased thermal environments, as mean thermal sensation vote (TSV) peaks when environmental relative humidity reaches the range of 70% to 80% and decreases after this range due to the evaporation within the microclimate created by a face mask. Meanwhile, prolonged mask wearing increases participants' hot feelings, especially in warm environments. Specifically, participants wearing face masks for less than 30 min feel hot at a physiological equivalent temperature (PET) value of 34.4 °C, but those who wear them for over 60 min express hot feelings even at a PET value of 24.7 °C. The participants who wear a face mask while walking slowly outdoors have similar thermal sensations to those who do not wear a mask, but are in a higher activity level. The findings demonstrate that mask wearing has a crucial impact on outdoor thermal comfort assessment in a warm-biased outdoor thermal environment.

A novel machine learning-based framework for mapping outdoor thermal comfort

ABSTRACT Rapid urbanization and global warming have increased heat stress in urban areas. This in turn makes using indoor space more compelling and leads to more energy consumption. Therefore, paying attention to outdoor spaces design with thermal comfort in mind becomes more important since outdoor spaces can host a variety of activities. This research aims to introduce a machine learning-based framework to predict the effects of different urban configurations (i.e. different greening configurations and types, different façade materials, and different urban geometry) on outdoor thermal comfort through training a pix2pix Convolutional generative adversarial network (cGAN) model. For the training of the machine learning model, a dataset consisting of 208 coupled pictures of input and output has been created. The simulation of this data has been carried out by ENVI-met. The resulting machine learning model had a Structural Similarity Index (SSIM) of 96% on the test dataset with the highest SSIM of 97.08 and lowest of 94.43 which shows the high accuracy of the model and it could have reached an answer in 3 s compared to the 30-min average time for ENVI-met simulation. The resulting model shows great promise for assisting researchers and urban designers in studying existing urban contexts or planning new developments. HIGHLIGHTS Machine learning use in outdoor thermal comfort assessment has been investigated. Vegetation, urban geometry, surface albedo, and water bodies have been studied parameters. Vegetation and street orientation have the highest and water bodies have the least impact on outdoor thermal comfort. Pix2pix algorithm implementation could create thermal comfort maps with 96% SSIM.

Predictive Capacity Analysis for Outdoor Thermal Comfort Assessments: A Case Study of Jijel City, Algeria

Ensuring acceptable thermal comfort conditions in public spaces is nowadays a major concern of urban design. A number of indices have been proposed in the literature, namely PMV, PET, SET*, UTCI, PT, mPET and MOCI. The present study aims to find the most suitable index the outdoor thermal comfort assessment in the city of Jijel by comparing the predictive capacities of these indices in terms of frequency occurrence and by relating them with the contextual responses of users. These indices are defined, their feature is analysed and finally explored. Thermal comfort based on these indices was evaluated using RayMan and Townscope softwares. The choice among these indices needs their comparison with data gathered from a survey by questionnaire. The findings indicate a slight agreement between these indices and the perceived sensation (PESV) values in the range of -1 and +1, especially with the indices SET* and mPET. However, for the classes +2 and +4, a significant disagreement is observed. For the class +3, however, only PET, PMV and SET* are more joined to the perceived sensation values. The disagreements may be related to the physical environment characteristics, the subjective perception, and the adaptation attitude of the users. Thus, further indices calibration investigation is needed for better prediction of comfort taking into account local specificities. Based on the indices which are relatively in agreement with PESV, a neutral air temperature of 19.8 °C in winter and 20.4 °C in summer for the city of Jijel is deduced. Also, a comfort zone of 17.3 to 22.4 °C in winter and 18 to 22.8 °C in summer is extrapolated.

Thermal Comfort Assessment of the Beijing Historical Town Blocks: Analysis of Indices and Applications

Thermal comfort indicates the sensation of humans towards the surrounding environment. This research work proposes a novel method for assessing thermal comfort indices of the Beijing Historical Town Blocks. Motivation. Maintaining a proper thermal comfort is essential for healthy living and promoting the use of low energy strategies; therefore, there is an intense need for research, analysis, and assessment of thermal indices for indoor environments. Objective. The research work intends to present a generalized model for outdoor thermal comfort assessment by investigating thermal comfort evaluation indices of the past ten years through the CiteSpace software and dynamic simulation system. Methodology. Based on a study of 19 streets over 6 blocks in the historical area of Beijing, validity of the four evaluation indices of thermal comfort of the street space is analyzed using real-time data monitoring, questionnaires, regression analysis, and model establishment. Statistical analysis is performed on the basis of the four commonly used thermal comfort evaluation indices along with using universal thermal climate index (UTCI) and the comfort threshold range for evaluation. Findings. Outcomes of the analysis revealed that UTCI thermal neutral value in the historic block was 20.59°C and the comfort range was 16–25°C. It was observed that UTCI indices were inversely related to the street vegetation coverage; therefore, unlike street aspect ratio and building shadow, green planting elements had a significant effect on the thermal comfort of outdoor environment. Implication. As applicability extent of the four indices is fairly broad, the proposed method is adaptable for the assessment of indoor and outdoor environments. Thermal comfort index analysis and evaluation are appropriate for advance research in microclimate environment. Application. The research work suggests improvement strategies of microclimate environment in the historical blocks and, therefore, has significant applications in addressing the challenges of outdoor thermal comfort systems.

Variations in outdoor thermal comfort in an urban park in the hot-summer and cold-winter region of China

• Outdoor thermal comfort is evaluated in an urban park in a hot-summer and cold-winter region of China (Chengdu). • Machine learning techniques are applied to determine the (nonlinear) relationship between thermal sensation vote and meteorological factors. • The effect of landscape spaces on human thermal comfort varies across the season. • NTR of PET is 6.79 °C to 19.90 °C, and NTR of UTCI is 13.27 °C to 27.25 °C. TAR of PET is 2.8 °C to 21.9 °C, and TAR of UTCI is 8.1 °C to 28.3 °C. Global warming and rapid urbanization have exacerbated the urban heat island effect. Urban parks contribute to alleviating such an effect and achieving the “carbon emission peak before 2030” and “carbon neutrality before 2060” goals of China. Their popularity is considerably influenced by human thermal comfort. However, limited thermal comfort studies have been conducted in the hot-summer and cold-winter region of China. This study examines human thermal comfort in different landscapes of an urban park in Chengdu and determines the thermal benchmarks. A machine learning (random forest) analysis shows that human thermal sensation is affected by different meteorological factors in different seasons. In addition, the influences of landscape space on human thermal comfort have considerable differences in different seasons. Residents prefer strong solar radiation in winter but fast wind speed in summer. UTCI (universal thermal climate index) is better than PET (physiological equivalent temperature) for outdoor thermal comfort assessment in the study area. This study serves as a valuable baseline and technical reference, contributing to sustainable urban park design.

Evaluating outdoor thermal comfort in urban open spaces in a humid subtropical climate: Chandigarh, India

This study deals with the assessment of outdoor thermal comfort in three distinct urban open space typologies (i.e. plaza, green and waterfront) in Chandigarh, India. Micrometeorological monitoring and transverse surveys eliciting 2523 valid responses were conducted during summer and winter seasons. PET was computed based on the measured micrometeorological variables. Benchmarks pertaining to thermoneutrality and thermal acceptability were established. The thermoneutrality of the respondents corresponded to a physiological equivalent temperature of 24.09 °C. Neutral temperatures and thermal sensation varied significantly between summer and winter. The respondents were more sensitive to the prevalent thermal environment in summer than winter. In addition, they considered the green spaces to be the most thermally comfortable among the open space typologies evaluated. The acceptable thermal comfort range was 20.2–36.6 °C. Thermal neutrality, acceptability and comfort varied significantly based on context and the attributes of open spaces.

Digital Simulation for Buildings’ Outdoor Thermal Comfort in Urban Neighborhoods

Buildings’ outdoor thermal comfort influences environment quality and human behavior in urban neighborhoods. The Universal Thermal Climate Index (UTCI) has been broadly applied to the study of buildings’ outdoor thermal comfort in urban areas. However, complex environmental conditions in climate-sensitive urban areas can make UTCI assessment complicated and ineffective. This paper introduces digital techniques into buildings’ outdoor thermal comfort analysis for the improvement of the urban habitant environment. A digital simulation system is generated to facilitate the analysis procedure for buildings’ outdoor thermal comfort assessment in urban neighborhoods. The analysis addresses the research question: “Can digital simulation techniques provide a modeling system to assess buildings’ outdoor thermal comfort continuously and effectively?” Methods include a case study of neighborhoods in Beijing, qualitative and quantitative analysis based on digital processes, and parametric modeling. The results indicate that digital simulation techniques and tools have the capability to support the analysis of buildings’ outdoor thermal comfort by providing three-dimensional models, algorithm-based analysis, and visual simulation. The findings include a critique of digital simulation as applied to architecture study and insights on potentially improving buildings’ outdoor thermal comfort through human–computer interactions.

The assessment of outdoor thermal comfort inside oasis settlements in North Africa - Algeria

Oasis settlements are the most common form in the Saharan regions of North Africa, identified by a strong harmony between urban forms and palm groves, which present the economic capital for these regions. On the other hand, these oases are significantly growing and impacting the people’s livelihood and thermal well-being, especially during summer season. This study aims at first to identify the close correlation between cultivated area (palm grove) and the built-up area throughout the Tolga Oasis Complex in Algeria, which is recognised by its palm groves and well-known as one of the largest oasis settlements of the Saharan regions in North Africa. Furthermore, the current work assesses the impact of palm groves by investigating the ‘oasis effect’ on the thermal heat stress levels during July and August daytime hours within 9 conducted stations. Suprisingly, the so-called oasis effect generated by palm groves was insignificant during the extreme hot days. On the other hand, the palm groves were extremly hot affected by a warming effect during daytime hours.

Assessment of Outdoor Thermal Comfort in Serbia’s Urban Environments during Different Seasons

The urban microclimate is gradually changing due to climate change, extreme weather conditions, urbanization, and the heat island effect. In such an altered environment, outdoor thermal comfort can have a strong impact on public health and quality of life in urban areas. In this study, three main urban areas in Serbia were selected: Belgrade (Central Serbia), Novi Sad (Northern Serbia), and Niš (Southern Serbia). The focus was on the temporal assessment of OTC, using the UTCI over a period of 20 years (1999–2018) during different seasons. The main aim is the general estimation of the OTC of Belgrade, Novi Sad, and Niš, in order to gain better insight into the bioclimatic condition, current trends and anomalies that have occurred. The analysis was conducted based on an hourly (7 h, 14 h, and 21 h CET) and “day by day” meteorological data set. Findings show the presence of a growing trend in seasonal UTCI anomalies, especially during summer and spring. In addition, there is a notable increase in the number of days above the defined UTCI thresholds for each season. Average annual UTCIs values also show a positive, rising trend, ranging from 0.50 °C to 1.33 °C. The most significant deviations from the average UTCI values, both seasonal and annual, were recorded in 2000, 2007, 2012, 2015, 2017, and 2018.

The Development of New Generation of Manikin for Outdoor Thermal Comfort Evaluation – A Literature Review

Urban Heat Island (UHI) is a challenge to human in the following decade as a result of continuous urbanization without appropriate planning and design. The impacts of UHI will getting worse due to the increase of population density with improper urban development especially in dense metropolitan cities. In the point of view of outdoor thermal comfort, a prolonged exposure to the outdoor heat will significantly contribute to human discomfort and health problems. Therefore, various research efforts have been implemented for developing solutions the mitigation strategies. The development of thermal manikin is one of mitigation effort to investigate the occurrence of UHI and to evaluate thermal comfort in microclimate conditions as representative of human simulation model. Hence, the aim of this paper is focused on the consideration that are required to develop a thermal manikin for outdoor thermal comfort assessment which include outdoor thermal comfort index, development of thermal manikin and material for thermal manikin for outdoor thermal comfort assessment.