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Article
Publication date: 30 November 2020

Miao Tian and Jun Li

The purpose of this study is to determine the effect of ventilation openings and fire intensity on heat transfer and fluid flow within the microclimate between 3D human body and…

Abstract

Purpose

The purpose of this study is to determine the effect of ventilation openings and fire intensity on heat transfer and fluid flow within the microclimate between 3D human body and clothing.

Design/methodology/approach

On account of interaction effects of fire and ventilation openings on heat transfer process, a 3D transient computational fluid dynamics model considering the real shape of human body and clothing was developed. The model was validated by comparing heat flux history and distribution with experimental results. Heat transfer modes and fluid flow were investigated under three levels of fire intensity for the microclimate with ventilation openings and closures.

Findings

Temperature distribution on skin surface with open microclimate was heavily depended on the heat transfer through ventilation openings. Higher temperature for the clothing with confined microclimate was affected by the position and direction of flames injection. The presence of openings contributed to the greater velocity at forearms, shanks and around neck, which enhanced the convective heat transfer within microclimate. Thermal radiation was the dominant heat transfer mode within the microclimate for garment with closures. On the contrary, convective heat transfer within microclimate for clothing with openings cannot be neglected.

Practical implications

The findings provided fundamental supports for the ease and pattern design of the improved thermal protective systems, so as to realize the optimal thermal insulation of the microclimate on the garment level in the future.

Originality/value

The outcomes broaden the insights of results obtained from the mesoscale models. Different high skin temperature distribution and heat transfer modes caused by thermal environment and clothing structure provide basis for advanced thermal protective clothing design.

Details

International Journal of Clothing Science and Technology, vol. 33 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 July 2006

Hiroyuki Ueda, Yoshimitsu Inoue, Mitsuo Matsudaira, Tsutomu Araki and George Havenith

The aim of this study is to explore the influence of the clothing ventilation in three body regions on the humidity of the local clothing microclimates under five work‐shirts…

1021

Abstract

Purpose

The aim of this study is to explore the influence of the clothing ventilation in three body regions on the humidity of the local clothing microclimates under five work‐shirts immediately after the onset of sweating in light exercise.

Design/methodology/approach

The clothing microclimate ventilations were measured at chest, back and upper arm using a manikin. Separate wear trials were performed to determine the sweat production and the humidity of the clothing microclimate at the same locations as where the ventilation was measured during light exercise.

Findings

Every shirt shows the greatest value of ventilation index (VI) for the chest and the smallest one for the upper arm. The values of VI differ remarkably at the chest among the five shirts. Comfort sensation became gradually worse as the time passed after starting exercise. There was no significant difference among the clothing conditions in mean values of rectal temperature, local skin temperatures, microclimate temperatures, microclimate relative humidities and local sweat rates at three regions over 10 min after the onset of sweating. A relationship was observed between the ratio of the mean moisture concentration in the clothing microclimate to the mean sweat rate at the chest and the back and the VI.

Originality/value

The results suggest that clothing ventilation should be measured in different body regions in response to sweat rates in corresponding regions.

Details

International Journal of Clothing Science and Technology, vol. 18 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 October 1999

E.J. Holland, C.A. Wilson, R.M. Laing and B.E. Niven

The rate and volume of air exchanged between the bed microclimate and the ambient environment determines in part how much heat is lost from the human body. This study investigated…

Abstract

The rate and volume of air exchanged between the bed microclimate and the ambient environment determines in part how much heat is lost from the human body. This study investigated the ventilatory characteristics of infant over‐bedding to determine whether different combinations of bedding items (i.e. sheets, blankets, duvets) and types of tucking (i.e. loosely, firmly and swaddled/firmly tucked) affected microclimate ventilation. Microclimate volumes and air exchange rates were determined and used to calculate the ventilation indices. The presence of a duvet in the bedding combination resulted in lower ventilation indices than when bedding did not include a duvet. The type and combination of blankets did not significantly affect ventilation indices. The type of tucking had a significant effect on ventilation indices only when the assembly did not include a duvet.

Details

International Journal of Clothing Science and Technology, vol. 11 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 15 May 2024

Yijie Zhang, Ziyi Guo, Jiangang Wei and Yijun Li

The aim of this paper is to achieve a reasonable microclimate between clothing and the human body and optimize the custom dress pattern.

Abstract

Purpose

The aim of this paper is to achieve a reasonable microclimate between clothing and the human body and optimize the custom dress pattern.

Design/methodology/approach

An interactive design method of 3D modeling, virtual try-on and heat transfer simulation are used. First, a 3D dress is designed with nonuniform rational B-splines curves and tried on virtually. After that, the heat transfer in the body-air-clothing microclimate and temperature distributions on the clothing surface are obtained. Based on the heat transfer in the body-air-clothing system, we design a method to improve the thermal comfort by optimizing the garment pattern digitally. Then, this paper utilized two heat transfer validating indexes to quantify the improvement of thermal comfort, and evaluate the modified model of dress.

Findings

The microclimate under the clothing is varied with the air gap distance, and the heat transfer on the area of the clavicle, bust point and front abandon are higher than other parts due to the narrow air gaps. In view of thermal comfort, the pattern optimization changes the distance ease and reforms the air circulating efficiency. The mean heat transfer and its standard variance are changing by about 10% and more than 20%. Thus, the heat transfer evaluation indexes are suitable to represent the heat transfer and thermal comfort in the microclimate system.

Research limitations/implications

It can be concluded that the methodology proposed in this paper has the advantage of interactive design, 3D visualization and local heat transfer simulation. This technology meets the need of personalized customization and well-considered garment and has broad application prospects.

Originality/value

This study demonstrates that modifying the distance ease on body key girths based on heat transfer is a reliable way to improve thermal comfort. This method meets the consumers’ demand of the comfort of body-fit clothing under the condition of daily activities.

Highlights

  • 3D air gap distributions.

  • Heat transfer varies with air gap distance.

  • Thermal comfort can be improved by optimizing garment pattern.

3D air gap distributions.

Heat transfer varies with air gap distance.

Thermal comfort can be improved by optimizing garment pattern.

Details

International Journal of Clothing Science and Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 22 March 2024

Saghar Hashemi, Amirhosein Ghaffarianhoseini, Ali Ghaffarianhoseini, Nicola Naismith and Elmira Jamei

Given the distinct and unique climates in these countries, research conducted in other parts of the world may not be directly applicable. Therefore, it is crucial to conduct…

Abstract

Purpose

Given the distinct and unique climates in these countries, research conducted in other parts of the world may not be directly applicable. Therefore, it is crucial to conduct research tailored to the specific climatic conditions of Australia and New Zealand to ensure accuracy and relevance.

Design/methodology/approach

Given population growth, urban expansions and predicted climate change, researchers should provide a deeper understanding of microclimatic conditions and outdoor thermal comfort in Australia and New Zealand. The study’s objectives can be classified into three categories: (1) to analyze previous research works on urban microclimate and outdoor thermal comfort in Australia and New Zealand; (2) to highlight the gaps in urban microclimate studies and (3) to provide a summary of recommendations for the neglected but critical aspects of urban microclimate.

Findings

The findings of this study indicate that, despite the various climate challenges in these countries, there has been limited investigation. According to the selected papers, Melbourne has the highest number of microclimatic studies among various cities. It is a significant area for past researchers to examine people’s thermal perceptions in residential areas during the summer through field measurements and surveys. An obvious gap in previous research is investigating the impacts of various urban contexts on microclimatic conditions through software simulations over the course of a year and considering the predicted future climate changes in these countries.

Originality/value

This paper aims to review existing studies in these countries, provide a foundation for future research, identify research gaps and highlight areas requiring further investigation.

Details

Smart and Sustainable Built Environment, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2046-6099

Keywords

Article
Publication date: 5 May 2020

Wafa Ghaffour, Mohammed Nabil Ouissi and Marc André Velay Dabat

The preservation of historic urban centres prevents anarchic development of the city and ensures a harmonious evolution of the urban form. It also improves the quality of life in…

Abstract

Purpose

The preservation of historic urban centres prevents anarchic development of the city and ensures a harmonious evolution of the urban form. It also improves the quality of life in the context of climate and environmental change. Morphological and geometric indicators of the urban fabric are key parameters in the formation of external microclimates. They provide a positive effect on the thermal comfort of pedestrians. The objective of this work is to study the impact of the site morphology on the external microclimate and to understand the relationship between the subjective perception and the objective quantification of the thermal environment. The result of this study has allowed us to propose solutions for the creation of a microclimate favourable to the appropriation of outdoor spaces. The authors finally propose guidelines for the design and rehabilitation of the historic site based on the establishment of links between the site's configuration, microclimatic conditions and users' perceptions.

Design/methodology/approach

Part of this study included the analysis of the microclimate of the historic “Bab El Hadid” district of the City of Tlemcen, by developing a questionnaire survey and a numerical simulation validated by measurements of the microclimate the authors made on site. To complete this task, the authors applied the Envi-met 4.1 model during the coldest month of the winter and the hottest month of the summer. Urban parameters are represented at different measurement points characterised by a variability of the sky view factor (SVF).

Findings

The results presented in terms of average expected the predicted mean vote (PMV) voting, solar access and air temperature. They show that thermal conditions are directly related to the SVF, the height/width ratio (H/L) of streets as well as the orientation of urban canyons. The points located in the streets facing North–South, present an acceptable performance. Streets shaded by trees with a canyon aspect ratio of between 1.18 and 1.70 reduce heat stress in outdoor spaces. The PMV models discussed provide information on the most appropriate locations for pedestrians. The authors have proposed urban orientations that could limit unfavourable conditions in outdoor spaces. They are useful for architects and urban planners in the design and rehabilitation of historic centres.

Originality/value

In Tlemcen, the microclimate is not taken into account in the design and rehabilitation of urban fabrics. For this specific purpose, the authors want to stress in the research the importance of safeguarding urban heritage through the renewal of the old city and the bioclimatic rehabilitation of its urban spaces.

Details

Smart and Sustainable Built Environment, vol. 10 no. 2
Type: Research Article
ISSN: 2046-6099

Keywords

Article
Publication date: 10 April 2019

Yan Hong, Xuechun Cao, Yan Chen, Zhijuan Pan, Yu Chen and Xianyi Zeng

The purpose of this paper is to investigate physiological indices related to comfort and health condition, based on which corresponding electronic equipment are selected and…

Abstract

Purpose

The purpose of this paper is to investigate physiological indices related to comfort and health condition, based on which corresponding electronic equipment are selected and applied. A wearable monitoring system using sensor and liquid crystal display (LCD) techniques are then designed. Sensors are used to collect and transmit recording required signals from the wearer. A microcomputer with the type of AT89C52 is used to record and analyze the collected data. LCD is applied to display the health and comfort condition of the wearer.

Design/methodology/approach

A novel wearable monitoring system for the measurement of physiological indices and clothing microclimate is proposed in this study in order to monitoring both health and comfort condition of the wearer.

Findings

The proposed system provides reference for the application of sensor and display technologies in the field of smart clothing, which can be further applied to infant and child care, health care, home entertainment, military and industry.

Originality/value

This paper, first, investigated a framework of a wearable monitoring system considering both comfort and health condition and summarized the related physiological indices. The requirements of both comfort and health condition monitoring are analyzed to select appropriate electronic elements.

Details

International Journal of Clothing Science and Technology, vol. 31 no. 3
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 27 May 2014

Grażyna Bartkowiak, Anna Dąbrowska and Anna Marszałek

People working in the hot environment are constantly exposed to the overheating, that can lead to cardiovascular disorders and as a consequence result in occupational diseases…

Abstract

Purpose

People working in the hot environment are constantly exposed to the overheating, that can lead to cardiovascular disorders and as a consequence result in occupational diseases. The purpose of this paper is to present developed personal liquid cooling system that is able to efficiently draw excess heat from the human organism, protecting against thermal stress.

Design/methodology/approach

The paper presents study concerning the assessment of effect of the coolant temperature in the developed liquid cooling garment (LCG) on physiological parameters of the subjects (heart rate, body temperature, skin temperature) and parameters of the undergarment microclimate, as well as subjective sensations reported by volunteers exercising in hot microclimate while wearing LCG and without LCG.

Findings

Obtained results of physiological parameters measurements, as well as undergarment physical parameters and volunteers subjective sensations, proved satisfactory level of thermal stress reduction while working in the aluminized protective clothing in hot environment by the developed personal liquid cooling system for the variant with coolant temperature 19°C and the flow rate 0.9 dm3/min.

Originality/value

This paper presents a new clothing construction intended for LCG that can efficiently support human thermoregulation processes while working in the hot environment.

Details

International Journal of Clothing Science and Technology, vol. 26 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 2 November 2015

Ying Ke, Jun Li and George Havenith

An experimental study was conducted to investigate the local ventilation (the right arm, the chest and the back) and wear response of three types of working jackets in different…

Abstract

Purpose

An experimental study was conducted to investigate the local ventilation (the right arm, the chest and the back) and wear response of three types of working jackets in different conditions. The relationship between the local ventilation and its related wear response was also explored. The paper aims to discuss these issues.

Design/methodology/approach

A clothing local ventilation measuring system was developed based on the steady state method to measure the local ventilation of the right arm, the chest and the back. Separate wear trials were conducted to determine the local skin temperature, local microclimate temperature and humidity, clothing local surface temperature, heart rate (HR), eardrum temperature and subjective perceptions.

Findings

The results indicated that the back part of the jacket had the highest ventilation, followed by the chest and the arm. Fabric permeability affected the local ventilation of the arm and the chest more than on the back. Clothing local surface temperature was significantly related to garment regions but not to fabric permeability. Back ventilation and back surface temperature, arm or chest ventilation and local microclimate humidity of the arm or chest, HR and back ventilation, local ventilation of the arm or the chest and its related thermal sensation, had significant linear relationships.

Originality/value

The research will help to understand the relationship between the air exchange of the microclimate and the wear response, and thus gives some suggestions on garment design or selection, especially for the working garments.

Details

International Journal of Clothing Science and Technology, vol. 27 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 20 July 2021

Yoon Jeong Baek, Seung-Hyun Kim, Sayup Kim, Eui-Sang Yoo and Joo-Young Lee

The purpose of the present study was to evaluate the effect of air mattress pressure on sleep quality.

Abstract

Purpose

The purpose of the present study was to evaluate the effect of air mattress pressure on sleep quality.

Design/methodology/approach

Ten young healthy males participated in all hard surface [AH], shoulder soft [SS] and shoulder and hip soft mattress [SHS] conditions. The surface pressure for SS and SHS were set at their preferred levels.

Findings

The results showed that sleep efficiencies were over 95% for all the three conditions; there were no significant differences in individual sleep variables among the three conditions, but overall sleep quality was better for SS than AH (p = 0.065); heart rates during sleep was greater for AH than the other two conditions (p < 0.1); and a stronger relationship between clothing and bed microclimate humidity were found for SS and SHS than that for AH.

Research limitations/implications

These results indicated that the both pressure relief air mattresses that were set at their own preferred levels provided high quality sleep with no marked differences.

Practical implications

Air pressure relief mattresses can improve sleep quality of healthy individuals during sleep at night. The results can be used to understand appropriate pressure distribution on surface mattress according to body region, and also to develop algorithms to provide optimum sleep using mattresses with surface pressure control by body region.

Originality/value

The present study found that the shoulder and/or hip pressure relief air mattresses that were set at their own preferred levels provided high quality sleep with no marked differences.

Details

International Journal of Clothing Science and Technology, vol. 34 no. 2
Type: Research Article
ISSN: 0955-6222

Keywords

1 – 10 of 551