scholarly journals Study on Outdoor Thermal Comfort in the Transitional Season of Hefei

2020 ◽  
Vol 165 ◽  
pp. 01026
Author(s):  
Jinwei Li ◽  
Lilin Zhao ◽  
Zheyao Peng ◽  
Zijian Wang ◽  
Taotao Shui

In order to study the outdoor thermal comfort during the transition season in Hefei, a university in Hefei adopted a combination of field environmental measurements and questionnaires to study the changes in thermal sensation and thermal comfort of outdoor people before and after the transition season. The rankings of the effects of temperature, wind speed, humidity, and solar radiation on human thermal comfort were obtained through surveys, and the proportion of each parameter’s influence on human thermal comfort was analyzed. The relationship between thermal sensation and thermal comfort was analyzed, and the application was established through regression analysis Prediction model of thermal sensation in autumn and winter outdoor environment in Hefei area.

2019 ◽  
Vol 29 (5) ◽  
pp. 730-745 ◽  
Author(s):  
Chunjing Shang ◽  
Xinyu Huang ◽  
Yufeng Zhang ◽  
Maoquan Chen

Considering the importance of thermal comfort in decision-making in tourism, a transverse study involving micrometeorological measurements and questionnaires was performed at a popular coastal destination during the seasons of spring, autumn and winter. We examined the thermal sensation and thermal acceptability using the physiological equivalent temperature (PET). The results indicate that tourists’ thermal sensations varied with the season and the neutral PETs were 19.2°C, 23.8°C and 23.3°C in winter, spring and autumn. The 90% acceptable ranges of the PET affected by the local climate were 19.6–29.5°C during the entire three-season survey period, 21.4–27.1°C in the spring, 19.2–32°C in the autumn and more than 15.9°C in the winter. The analysis of microclimate parameters that affect thermal comfort in three seasons reveals that people expected weaker solar radiation, stronger wind and lower humidity with the air temperature rising, and vice versa. The acceptable range of wind speed was 0.6–2.5 m/s in winter, 0.6–3.5 m/s in spring and autumn. The acceptable range of solar radiation was 0–150 W/m2 in autumn and 0–250 W/m2 in winter. These findings contribute to the better designs for coastal facilities and the thermal comfort of tropical areas.


2015 ◽  
Vol 33 (2) ◽  
Author(s):  
Anderson Spohr Nedel ◽  
Fábio Luiz Teixeira Gonçalves ◽  
Celso Macedo Junior ◽  
Maria Regina Alves Cardoso

ABSTRACT. The purpose of this study is to carry out a climatological analysis of human thermal comfort in the São Paulo city, Brazil, for outdoor and indoor environments, applying different indexes of thermal comfort in order to assess which of them represent best the weather characteristics of the São Paulo city. The relationship between these indexes and the seasons (fall, winter, spring, summer) was investigated in the period from 1980 to 2005, for outdoor environments, and during 2005, for the indoor environments. The results showed that the most appropriate index for São Paulo, both for internal and external conditions was the Effective Temperature Index (ET) as it has a broad classification and can provide appropriate representations of the region’s comfort. According to this index, the mornings during summer in the outdoor environments showed mild discomfort by cold, and the afternoons were comfortable. In winter, there was thermal stress by cold during the mornings and a slight discomfort by cold during the afternoons. For indoor environments in the summer, most of the houses presented comfortable mornings, and afternoons with discomfort in relation to the heat, while in the winter, period proved to be uncomfortable and stressful due to cold and the afternoonscharacterized themselves as comfortable.Keywords: thermal sensation, biometeorology, biometeorological indexes.RESUMO. O objetivo deste estudo é realizar uma análise climatológica do conforto térmico humano na cidade de São Paulo, Brasil, para ambientes externos e internos, aplicando diferentes índices de conforto térmico, a fim de avaliar qual deles melhor representa as características climáticas da cidade de São Paulo. A relação entre esses índices e as estações do ano (outono, inverno, primavera, verão) foi investigada no período compreendido entre 1980 e 2005 para os ambientes externos, como também durante o ano de 2005 para os ambientes internos. Os resultados mostraram que o índice de Temperatura Efetiva (TE) é o mais apropriado para São Paulo, tanto para condições internas quanto externas, pois este possui uma classificação ampla e pode fornecer representações adequadas do conforto da região. Segundo esse índice, as manhãs, durante o verão nos ambientes externos, apresentaram leve desconforto por frio, e as tardes estiveram confortáveis. Já no inverno, observou-se estresse térmico por frio durante as manhãs e um ligeiro desconforto por frio no período das tardes. Para os ambientes internos, a maioria das casas apresentou no verão manhãs confortáveis e tardes com desconforto em relação ao calor; já no inverno, o período das manhã mostrou-se desconfortável e estressante devido ao frio e as tardes caracterizaram-se como confortáveis.Palavras-chave: sensação térmica, biometeorologia, índices biometeorológicos.


2020 ◽  
Vol 12 (5) ◽  
pp. 1876 ◽  
Author(s):  
Zheng Zhu ◽  
Jing Liang ◽  
Cheng Sun ◽  
Yunsong Han

This paper investigates outdoor thermal comfort in summer in commercial pedestrian streets in Harbin, using meteorological measurements and questionnaire surveys (1013 valid questionnaires). The results demonstrate that: (1) Thermal sensation has a lower range in an outdoor environment with smaller sky view factor (SVF) and less fluctuation, while the thermal sensation vote (TSV) range is more dispersed in an outdoor environment with larger SVF and more fluctuation; (2) In the urban, high-density commercial districts in Harbin, the air temperature and solar radiation have a greater influence on outdoor thermal sensation, while wind speed has less of an influence, and residents in areas with less fluctuations are more sensitive to air temperature and solar radiation; (3) The universal thermal climate index (UTCI) can accurately evaluate outdoor thermal comfort in Harbin in summer, with a neutral UTCI value of 19.3 °C and a range from 15.6 to 23.0 °C; (4) The actual acceptable thermal range is 16.8–29.3 °C, and this takes into account the psychological adaptation of the residents, which provides a more practical reference value; (5) With reference to the psychological adaptation, the outdoor thermal sensation of residents in early summer is about 0.5 TSV higher than that in late summer. These results provide a theoretical basis and a technical reference for the design of commercial pedestrian streets in severe cold regions.


2018 ◽  
Vol 89 (12) ◽  
pp. 2316-2329 ◽  
Author(s):  
Peijing Li ◽  
Yun Su ◽  
Qianqian Huang ◽  
Jun Li ◽  
Jingxian Xu

To understand the effectiveness of some garment adjustment designs for high school uniform in winter, manikin tests and subjective wear trials were carried out. Five series of school uniform ensembles were involved in the experiments. They were further collocated into 17 ensemble configurations with detachable designs (ensembles A and B) and opening structures (ensembles C, D, and E). As manikin test results showed, the thermal insulation of ensembles A, B and C varied most significantly due to their adjustment design. The possible thermal insulation regulation levels were approximately 68% and 80% for ensembles A and B, and 60% and 90% for ensemble C. Two human trials that simulated students’ daily movements between indoor and outdoor classes were conducted with ensemble A. Two climate chambers were used at the same time for indoor and outdoor environment simulation. In Case X, where ensemble A was assumed to be non-detachable, skin temperatures that were 0.6℃ lower were finally observed compared to Case Y, where ensemble A was detachable. Moreover, significantly ( p < 0.1) better thermal comfort and thermal sensation evaluations were given during low-intensity activities in Case Y, especially for the torso segments. The detachable high school uniform design was finally proved to be efficient in improving human thermal comfort under various class environments. It was also concluded that more protective measures should be adopted for the hands and face in the school uniform design process.


2020 ◽  
Vol 11 (2) ◽  
pp. 326-341
Author(s):  
Golnoosh Manteghi ◽  
Tasneem Mostofa ◽  
Hasanuddin Bin Lamit

The present study aims to establish a correlation between the physiological equivalent temperature (PET) and subjective thermal sensation in the Tropics, assessing their impact on local as well as international pedestrians. The pilot test was conducted in six scenarios in the Malacca region of Malaysia. The RayMan model calculated the PET, which is further used to synthetically evaluate the thermal environment for six scenarios, each with a different river width and pavement material. The independent t-test and regression analysis determined the correlation between human thermal comfort acceptability and the thermal environment indices of outdoor spaces. Most of the outdoor thermal comfort assessments have been carried out focusing on local urban residents, while the same assessments on tourists are limited. This research provides necessary insight into the perception of outdoor microclimatic conditions in the Malacca heritage area and also identifies the perception on a few important psychological factors of these two demographic groups. An awareness of such issues would be fruitful for architects, planners and urban designers engaged in the process of designing and planning tourist destinations.


2015 ◽  
Vol 650 ◽  
pp. 82-90 ◽  
Author(s):  
D. Kannamma ◽  
A. Meenatchi Sundaram

The climatic conditions in a man-made urban environment may differ appreciably from those in the surrounding natural or rural environs.... each urban man-made buildings, roads, parking area, factories......creates around and above it a modified climate with which it interacts [1].Outdoor thermal comfort has gained importance in thermal comfort studies especially in tropical countries. In country like India, culturally the activities are spread both indoors and outdoors. Therefore the need for ambient outdoor environment gains importance. As there are many factors that contribute to outdoor thermal comfort (climatic factors and physical factors), this study aims in analyzing the impact of building material contribution, in an institutional courtyard. In order to understand the thermal contribution of various building materials and to suggest material choice to designers, ENVIMET is used for simulation purpose. The outdoor thermal comfort index employed in this study is PET (Physiological Equivalent Temperature), calibrated using RAYMAN.


Author(s):  
Pardeep Kumar ◽  
Amit Sharma

Outdoor thermal comfort (OTC) promotes the usage frequency of public places, recreational activities, and people's wellbeing. Despite the increased interest in OTC research in the past decade, less attention has been paid to OTC research in cold weather, especially in arid regions. The present study investigates the OTC conditions in open spaces at the campus area in the arid region. The study was conducted by using subjective surveys(questionnaire) and onsite monitoring (microclimate parameters). The study was conducted at the Deenbandhu Chhotu Ram University of Science and Technology, Murthal, Haryana-India campus during the cold season of 2019. The timings of surveys were between 9:00 and 17:00 hours. The authors processed the 185 valid questionnaire responses of the respondents to analyze OTC conditions. Only 8.6% of the respondents marked their perceived sensation "Neutral." Regression analysis was applied between respondents' thermal sensations and microclimate parameters to develop the empirical thermal sensation model. The air temperature was the most dominant parameter affecting the sensations of the respondents. The empirical model indicated that by increasing air temperature, relative humidity, and solar radiation, the thermal sensations also increased while wind speed had an opposite effect. Physiological equivalent temperature (PET) was applied for assessing the OTC conditions; the neutral PET range was found to be 18.42-25.37°C with a neutral temperature of 21.89°C. The preferred temperature was 21.99 °C by applying Probit analysis. The study's findings could provide valuable information in designing and planning outdoor spaces for educational institutions in India's arid regions


2021 ◽  
Vol 25 (2) ◽  
pp. 85-101
Author(s):  
Try Ramadhan ◽  
Aldissain Jurizat ◽  
Andina Syafrina ◽  
Amat Rahmat

Campus building was a place to accommodate various educational activities, which were both carried out indoors and outdoors. The environment, including the building and its exterior, provided thermal comfort that was influenced by the context, such as the mass of the facility, vegetation, and constructing envelope materials. The microclimate also influenced the environment, such as temperature, wind speed, and humidity. This study aimed to investigate the outdoor thermal comfort of campus building in urban area during summer, while also identifying the influential factors. This research referred to a case study, examining the thermal quality of the educational building environment using ENVI-met software, based on the Predicted Mean Vote (PMV) index as an indicator of outdoor thermal comfort, in Universitas Kebangsaan (UK). The results showed that the outdoor environment had low thermal comfort conditions during the day, as it also had different thermal satisfactory situations, due to differences in physical characteristics in each zone. This characteristics included, (1) The SVF determinant as indicators of the shading factor should be supported by the presence of vegetation and the use of pavement material, (2) Although the wind speed factor does not really affect the thermal comfort in the outdoor space, the interconnection between open gaps is likely to make breeze distribution in the area better. This study offered direction for campus planning, in order to maintain the optimal capacity of the natural environment, such as (1) Strategizing to create a better shadowing factor in the outer space, which was supported by controlling the use of pavement materials, (2) Directing the density of buildings by making open spaces more permeable, in order for better wind distribution in the area. From this study, the campus current conditions and future design development potential was also observed.


Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 391 ◽  
Author(s):  
João Gobo ◽  
Marlon Faria ◽  
Emerson Galvani ◽  
Fabio Goncalves ◽  
Leonardo Monteiro

The bioclimatic well-being of individuals is associated with the environmental characteristics of where they live. Knowing the relationships between local and regional climatic variables as well as the physical characteristics of a given region and their implications on thermal comfort is important for identifying aspects of thermal sensation in the population. The aim of this study is to develop an empirical model of human thermal comfort based on subjective and individual environmental patterns observed in the city of Santa Maria, located in the state of Rio Grande do Sul, Brazil (Subtropical climate). Meteorological data were collected by means of an automatic meteorological station installed in the city center, which contained sensors measuring global solar radiation, air temperature, globe temperature (via a grey globe thermometer), relative humidity and wind speed and direction. A total of 1720 people were also interviewed using a questionnaire adapted from the model recommended by ISO 10551. Linear regressions were performed to obtain the predictive model. The observed results proposed a new empirical model for subtropical climate, the Brazilian Subtropical Index (BSI), which was verified to be more than 79% accurate, with a coefficient of determination of 0.926 and an adjusted R2 value of 0.924.


Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1324 ◽  
Author(s):  
Xuan Ma ◽  
Hiroatsu Fukuda ◽  
Dian Zhou ◽  
Mengying Wang

The growth of the scale of cities intensifies urban heat island (UHI) by obstructing the wind and building more radiation at pedestrian level, thus leading to an energy consumption. Commercial pedestrianized-zones cannot only become symbols of cities but also an important factor increasing local economic income. This study conducts on-site measurement and numerical simulation to evaluate the cooling energy efficiency of different parameters (building, vegetation, pavement material) in Fo Shan city, which locates in hot-summer and warm-winter climate region of China. Also, calculations are done to evaluate the index physiological equivalent temperature (PET) for understanding thermal sensation at a pedestrian level (1.5 m). To evaluate different impacts of this zone renewal on the environment and choose the most energy-saving method, it is easy for us to utilize the linear regression for understanding the relationship between coverage ratio of trees (TCR) and thermal comfort in canyon space, which shows that ∆PET = 0.1703 × TCR + 0.2444 with a most important R2 value of 0.9836, for TCR increases from 12.5% to 22%. In open space, also increasing coverage ratio of trees (TCR) can effectively improve humans’ thermal comfort, which shows that ∆PET = 0.2644 × TCR + 0.3955 with a most important R2 value of 0.8892.


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