Standard Methods for Thermal Comfort Assessment of Clothing

Ivana Špelić, Alka Mihelić-Bogdanić, Anica Hursa Šajatović

• Publisher: CRC Press
• Year: 2019
• Print ISBN: 9781138391475
• eBook ISBN: 9780429750649
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Chemical & Biochemical Engineering
• Index: Technology & Engineering

Providing detailed analysis of the thermal comfort assessment of clothing as the basis for developing standards, this book discusses the thermal protective role of clothing as a way of modelling heat transfer from the body, general thermal regulation of humans, and the importance of globally accepted test methods and standards to improve quality.

New materials and discoveries in the study of thermal comfort necessitate the need for standard improvements and update. The development of international standards and the unification of testing methods is of crucial significance to ensure cost reduction and health protection. The book promotes instruments, methods, implementation of unified specifications, and the definition of standards so that a clear quality management system can be established, for both production systems and testing methods. It discusses standards in ergonomics of the thermal environment, clothing thermal characteristics, and subjective assessment of thermal comfort, which allows for systematic control of the measuring methods and the services and final products that are distributed on the global market.

This book is aimed at industry professionals, researchers, and advanced students working in textile and clothing engineering, comfort testing, and ergonomics.

1	Introduction

Vast knowledge of the principles of human physiology is required by practitioners for conducting most of the tests and measurements involving clothing. Since clothing is merely a part of the greater body–clothing–environment system, every single component of this system is connected and dependent on the other.

The heat and mass transfer pathways through textile and clothing structures are complex, and often a few simultaneous transport processes occur. Since clothing is a basic human need for survival, along with the food and shelter (Textile Technology, 2006), scientists and industry practitioners put a lot of effort into scientific research and technological improvements for producing textile structures and clothing for different end users and applications. Continuous improvements emerge on a daily basis for assisting with the thermal and moisture regulation of the human body through fibres, yarns and fabric construction engineering, and by developing special protective clothing for different environmental conditions and working environments.

New fabric and other textile materials are continuously designed in order to protect the human body from outside agents and to (Heat & Mass Transfer in Textiles, 2011):

1. Modify the water vapour and moisture loss rate of the insensible perspiration thus assisting the skin in conserving essential levels of body fluids or to cool the body.
2. Modify the heat loss rate of to keep the body in a cold environment at its critical internal temperature.
3. Keep the moisture penetration in the form of the rain and snow from the outside ambient to the skin and causing the body to become too cold.
4. Absorb solar hazardous electromagnetic waves and substances, such as ultraviolet radiation and toxic gases.
5. Block the penetration of harmful fluids such as blood-containing pathogens.

When it comes to clothing, its basic role is to modify the heat transfer between the human body and the environment. In this manner, the design process should always consider the intended usage and final purpose of the clothing. The other important factor to consider is the individual variations in heat exchange rate. The heat exchange rate varies greatly from person to person, for the various activities concerned and for the type of clothing worn (Gagge and Nishi, 1977). Finding common ground between the functional details needed, the production costs and the optimum design, which can provide the intended protection for the average consumer, involves the integration of various requirements in an all-around multidisciplinary approach.

In the past, testing of specialised protective clothing mainly concentrated on the material requirements and a few important clothing properties, although an important advantage of material test methods are that they are designed to produce accurate and reproducible results, both within and between laboratories, at minimal cost (Havenith and Heus, 2004).

Over the last few decades, clothing and textile design was driven by government and military needs for functional, protective and well-fitted garments, and performance-based garments for sport clothing companies. A new problem-solving design research area emerged focusing on both quantitative and qualitative methods in addition to practice (Bye, 2010).

Contemporary clothing design follows the crossover, multidisciplinary approach to clothing design involving the cooperation of two or more different areas for dealing with the more psychological needs of the complex survival environment. Growing clothing design requirements impose great diversification in the designs. The multidisciplinary design process incorporates human body engineering, medicine, chemical technology, nanotechnology, biotechnology, optics and many other disciplines. Besides the traditional people-oriented principle, the contemporary clothing design is fostered by new innovative material developments, the need for higher performance, development of intelligent clothing, the assistance of virtual technology and the need for sustainable and ecological development (Chunyan and Yue, 2014). Various effects need to be taken into account during the design development and testing of the protective clothing. These are the effects of the manufacturing process on the material’s properties (stitching, seams, treatments), the effects of clothing design, sizing and fit, the effect of the interaction of the clothing with other components or gear and how the clothing performs in actual use (Havenith and Heus, 2004). The trend of developing multifunctional fashion garments, defined as clothing or clothing systems that allow adaptation to diverse social situations or weather conditions, or simply as having different characteristics for different body areas in order to have different functional features, resulted in new design requirements. One of the basic requirements of clothing design is the issue of comfort (Cunha and Broega, 2009).

In the light of thermophysiological comfort, clothing generally has to be designed to (Angelova, 2016; Vecchi et al., 2017):

1. Protect the human body from weather conditions.
2. Protect from cold and solar radiation.
3. Provide a protective barrier against heat flows (open fire and high temperatures).
4. Provide sufficient comfort in a physical and psychological sense, regardless of the type of activity.

The development of standards related to thermal comfort and the unification of testing methods are of crucial significance to the global market. This allows for clear communication of the product’s performance, as well as allowing comparison between products and their materials from different producers. Information, requirements and quality control, which are described in international standards, provide applications for specific market segments and ensures that consumers’ needs are fulfilled worldwide. Unlike regulations, which are general laws that cover an entire sector rather than a single product, standards are more complex. Regulations typically set out only a general framework while standards are voluntary but provide more detail on rules, guidelines or characteristics for a product or process. In the absence of an official international standard, one can also use standards from the national organisation for standardisation.

The current definitions of standards always emphasise their voluntary nature. The Agreement on Technical Barriers to Trade by the World Trade Organization defines a standard as a document approved by a recognised body providing for common and repeated use rules, guidelines or characteristics for products or related processes and production methods compliance with which is not mandatory (Agreement on Technical Barriers to Trade, 1995). Similar terminology is also visible in the ISO definition of standards. In ISO/IEC Guide 2, a standard is defined as a document established by consensus and approved by a recognised body, providing for common and repeated use rules, guidelines, or characteristics for activities or their results aimed at the achievement of the optimum degree of order in a given context. The guide defines standardisation as the activity of establishing – with regard to actual or potential problems – provisions for common and repeated use aimed at the achievement of the optimum degree of order in a given context (ISO/IEC Guide 2:2004).

The standards provide the establishment of unique and generally accepted guidelines, methods and regulations, which define the requirements for production processes, quality control and the product itself. They also provide a uniform approach to doing something through open access for the general good. The adoption of standards should support efficiency and overall cost reduction through competition while ensuring product quality, interoperability, safety and reliability. Standards represent a consensus between experts on the best way of doing something. They do not require an inventive step; rather, they document ‘good practice’ (Taylor and Kuyatt, 1994; Hatto, 2001).

There are a vast number of standards currently in usage around the globe, but only the ISO standards are considered as truly international standards. Since states and governments cannot be members, the ISO is best described as a centrally coordinated global network comprising hundreds of technical committees from all over the world and involving thousands of experts representing industries and other groups for developing and regularly maintaining technical standards. The ISO has grown into the world’s largest and most widely recognised standards development organisation (O’Connor, 2015). The ISO’s influence is exercised due to size, popularity and recognition. The World Trade Organization (WTO) placed the ISO with a status of the world’s ‘trade-legal’ organisation (Morikawa and Morrison, 2004).

The ISO is formed of a global network of national standards bodies and serves as a global network of the world’s leading standardisers. As a leading international organisation, the ISO is nowadays one of the most significant generators of contemporary analysing standards, although none of the international associations mentioned does the product testing itself. Most of the European national standards organisations are simultaneously members of the ISO such as the BSI (British Standards Institution), the DIN (German Institute for Standardization), the SNV (Swiss Association for Standardization), etc. There are also American national standards organisations, which market their products internationally, the ASTM and ANISI/ASHRAE. Thanks to the work performed by these organisations, nowadays there is around 19,500 ISO standards, 12,000 ASTM standards and a few regular ASHARE publications in usage (Špelić et al., 2016).

The advance in technology during and after the Industrial Revolution was accompanied by simultaneous progress in standards development, both in terms of scope and number. A great deal of standards similar to technical specifications emerged as a means of making mass production economically viable and globally applicable. The standardisation of production methods and products stimulated rapid business adaptation (Standardization: Fundamentals, Impact, and Business Strategy, 2010). However, standards should be continually reviewed in terms of new knowledge and future requirements to provide the best available methods for the future (Parsons, 2013).

There is still much work to do since there are almost no evident standards for clothing aimed at protecting against cold environments in comparison to standards for clothing aimed at protecting against heat and flames. Another evident flaw is the lack of any standards that address the requirements for everyday clothing, which doesn’t fall in the scope of the protective clothing, but there is still great need to specify minimum requirements in order to produce optimum protection against cold.

This book is arranged into nine affiliated chapters. The first chapter is introductory and gives insight to the basic themes covered in the book. The second chapter provides detailed insights on human thermoregulation, from fundamental principles to different approaches in explaining the basic concepts of thermoregulation in humans. The focus is to explain the physiology of thermoregulation in humans that lies in the versatile description of the nervous system, temperature control mechanisms and energy transport modes. Chapter 3 covers the basic principles of a thermal comfort study, heat and moisture transmission through textiles and clothing, the function of clothing in preventing heat losses and factors influencing the ability to maintain a satisfactory thermal state. Chapters 4 to 9 discuss the details of thermal comfort standards: the globally accepted test methods for textile and clothing comfort testing; the basic principles...

Table of contents

• Cover
• Half-Title
• Series
• Title
• Copyright
• Dedication
• Contents
• Preface
• Textile Institute Professional Publications
• Author Bios
• Chapter 1 Introduction
• Chapter 2 Behind the Scenes: Thermal Regulation in Humans
• Chapter 3 Modelling Heat Losses from the Human Body
• Chapter 4 The Importance of Globally Accepted Test Methods and Standards
• Chapter 5 Why Use Thermal Comfort Standards?
• Chapter 6 Who Creates Standards?
• Chapter 7 The Standardisation of Thermal Comfort
• Chapter 8 The Distribution of Standards on Thermal Comfort
• Chapter 9 Overview of the Most Significant Standards on Thermal Comfort
• Index
• Standards Index