Experimental study on the thermal regulation performance of winter uniform used for high school students

2018 ◽  
Vol 89 (12) ◽  
pp. 2316-2329 ◽  
Author(s):  
Peijing Li ◽  
Yun Su ◽  
Qianqian Huang ◽  
Jun Li ◽  
Jingxian Xu
Keyword(s):  
High School ◽  
High School Students ◽  
Thermal Comfort ◽  
Thermal Insulation ◽  
Thermal Sensation ◽  
Uniform Design ◽  
Outdoor Environment ◽  
Human Thermal Comfort ◽  
School Uniform ◽  
Indoor And Outdoor

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.

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
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Outdoor Environment ◽  
Outdoor Thermal Comfort ◽  
Human Thermal Comfort ◽  
Transition Season ◽  
Before And After ◽  
Effects Of Temperature ◽  
Autumn And Winter ◽  
The Relationship

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.

scholarly journals Empirical Model of Human Thermal Comfort in Subtropical Climates: A First Approach to the Brazilian Subtropical Index (BSI)

Atmosphere ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 391 ◽  
Author(s):  
João Gobo ◽  
Marlon Faria ◽  
Emerson Galvani ◽  
Fabio Goncalves ◽  
Leonardo Monteiro
Keyword(s):  
Thermal Comfort ◽  
Empirical Model ◽  
Thermal Sensation ◽  
Meteorological Data ◽  
Well Being ◽  
Global Solar Radiation ◽  
Coefficient Of Determination ◽  
Subtropical Climate ◽  
Human Thermal Comfort ◽  
The City

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.

A Fan in Winter

1983 ◽  
Vol 27 (8) ◽  
pp. 742-745 ◽  
Author(s):  
Frederick H. Rohles ◽  
Byron W. Jones
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Test Chamber ◽  
Air Velocity ◽  
Subjective Responses ◽  
Human Thermal Comfort ◽  
Significant Difference ◽  
Maximum Period ◽  
Air Space ◽  
Indoor Conditions

In order to determine the effect of ceiling fans on human thermal comfort under winter indoor conditions, 72 subjects (36 men and 36 women) were exposed to 21°C/40% rh for 3 hours while experiencing still air conditions (0.08 m/s) and air velocities where a ceiling fan was operating in a upward-thrust mode at 2 velocities (0.18 and 0.28 m/s). Two subjective responses, thermal sensation and thermal comfort, were recorded each half hour. The results showed that after 2 hours, which may be assumed to be the maximum period of time that an individual would sit without getting up, the subjects recorded (1) the same neutral thermal sensation when the fan was at the still air condition (0.0 8 m/s) as when it was producing an air velocity of 0.18 m/s, (2) a slightly cool thermal sensation at a velocity of 0.28 m/s and (3) no significant difference in thermal comfort between still air (0.08 m/s) and velocities up to 0.28 m/s. It was concluded that the air movement created by operating the ceiling fan under winter conditions does not contribute to nor detract from human comfort nor did it produce any response resembling wind chill. These results were considered conservative since no temperature stratification existed in the test chamber air space which would be expected in exist in a conventionally heated room space.

scholarly journals Impact of ventilation system type on indoor thermal environment and human thermal comfort in a ceiling cooling room

2021 ◽  
pp. 277-277
Author(s):  
Xiaozhou Wu ◽  
Genglin Liu ◽  
Jie Gao ◽  
Shuang Wu
Keyword(s):  
Thermal Comfort ◽  
Air Temperature ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Physical Parameters ◽  
Curtain Wall ◽  
Indoor Thermal Environment ◽  
Human Thermal Comfort ◽  
System Type

A ceiling cooling (CC) system integrated with a mechanical ventilation system is an advanced HVAC system for the modern office building with glass curtain wall. In this paper, considering the influence of heat transfer of external envelope, the indoor thermal environment and human thermal comfort were objectively measured and subjectively evaluated in a ceiling cooling room with mixing ventilation (MV) or underfloor air distribution (UFAD). Indoor physical parameters and human skin temperatures were measured as the chilled ceiling surface temperature and supply air temperature were 17.1?C-17.6?C and 22.2?C - 22.6?C. Simultaneously, 16 subjects (8 males and 8 females) were selected to subjectively evaluate the thermal environment. The results showed that the difference between mean radiant temperature and air temperature in the occupied zone was 0.8?C with CC+MV and 1.2?C with CC+UFAD, and the indoor air velocity was 0.17m/s with CC+MV and 0.13m/s with CC+UFAD. In addition, the calculated and measured thermal sensation votes with CC+MV were all slightly less than those with CC+UFAD. Therefore, ventilation system type had a slight impact on the indoor thermal environment and human thermal comfort in the ceiling cooling room.

scholarly journals The Effect of Thermal Comfort on Stress in Female High School Students

2018 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Najmeh Najafi ◽  
Khosrow Movahed ◽  
Zahra Barzegar ◽  
Siamak Samani
Keyword(s):  
High School ◽  
High School Students ◽  
Thermal Comfort ◽  
School Students ◽  
Female High School

scholarly journals CLIMATOLOGY OF THE HUMAN THERMAL COMFORT ON SÃO PAULO METROPOLITAN AREA, BRAZIL: INDOORS AND OUTDOORS

2015 ◽  
Vol 33 (2) ◽  
Author(s):  
Anderson Spohr Nedel ◽  
Fábio Luiz Teixeira Gonçalves ◽  
Celso Macedo Junior ◽  
Maria Regina Alves Cardoso
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Sao Paulo ◽  
Winter Period ◽  
Indoor Environments ◽  
São Paulo ◽  
Human Thermal Comfort ◽  
Outdoor Environments ◽  
External Conditions ◽  
The Relationship

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.

Determination of human thermal comfort due to moisture permeability of clothes

2018 ◽  
Vol 30 (4) ◽  
pp. 462-476 ◽  
Author(s):  
Krittiya Ongwuttiwat ◽  
Sudaporn Sudprasert ◽  
Thananchai Leephakpreeda
Keyword(s):  
Water Vapor ◽  
Thermal Comfort ◽  
Thermal Sensation ◽  
Ambient Air ◽  
Coefficient Of Determination ◽  
Human Comfort ◽  
Content Type ◽  
Human Thermal Comfort ◽  
Moisture Permeability

Purpose The purpose of this paper is to present the determination of human thermal comfort with wearing clothes, with different water vapor permeability. Currently, the predicted mean vote (PMV) equation is widely used to determine thermal sensation scales of human comfort. However, moisture permeability of clothes has been not taken in account where the heat is lost from a human body due to water vapor diffusion through clothes. Design/methodology/approach In this study, the heat loss is derived based on the real structure of textiles, causing water vapor pressure difference between air on skin and ambient air. The PMV equation is modified to differentiate a thermal sensation scale of comfort although patterns of clothes are the same. Interview tests are investigated with wearing clothes from three types of textiles: knitted polyester, coated nylon–spandex, and polyurethane, under various air conditions. Findings The moisture permeabilities of knitted polyester, coated nylon–spandex and polyurethane are 16.57×10−9 kg/m2 s•kPa, 9.15×10−9 kg/m2•s•kPa and 2.99×10−9 kg/m2•s•kPa, respectively. The interviews reveal that most people wearing knitted-polyester clothes have the greatest cold sensations under various air conditions since moisture permeability is the highest, compared to coated nylon–spandex, and polyurethane leather. Correspondingly, the predicted results of the modified PMV equation are close to the actual mean votes of interviewees with a coefficient of determination R2=0.83. On the other hand, the coefficient of determination from the predicted results of the conventional PMV equation is significantly lower than unity, with R2=0.42. Practical implications In practice, this quantitative determination on human thermal comfort gives some concrete recommendations on textile selection of clothes for acceptable satisfaction of thermal comfort under various surrounding conditions of usage. Originality/value The modified PMV equation effectively determines human comfort on a thermal sensation scale due to the moisture permeability of clothes. To make generic conclusion, experimental results of additional three textiles, such as plain weave/lining polyester, knitted spandex, and open structure polyester, are reported. They confirm that the modified PMV equation effectively determines human comfort on a thermal sensation scale due to the moisture permeability of clothes.

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