ISO INTERNATIONAL STANDARD 5085-1 First edition 1989-11-15 Textiles --- Determination of thermal resistance : Part 1 : Low thermal resistance Textiles - Determination de la resistance thermique Partie 1: Faible resistance thermique Reference number ISO5085-1:1989 (E) ISO5085-1:1989(E) Foreword iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (Iso member bodies). The work of preparing International Standards is normally carried out through ISo technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISo, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by least 75 % approval by the member bodies voting. International Standard ISO 5085-1 was prepared by Technical Committee ISO/TC 38, Textiles. Iso 5085 consists of the following parts, under the general title Textiles -- Determi- nation of thermal resistance: Part 1: Low thermal resistance Part 2:Highthermal resistance Annexes A to D form an integral part of this part of ISo 5085. ISO 1989 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 . CH-1211 Geneve 20 . Switzerland Printed in Switzerland ii ISO 5085-1 : 1989 (E) Introduction The thermal insulation provided by woven and knitted fabrics and nonwoven fibre ag- gregates (fleeces, batts and wads) is of considerable practical significance in connec- tion with the use of these materials as clothing (especially cold-weather clothing), bed- ding (blankets, quilts), carpets, roof insulation, etc. The measurement of the thermal resistance of textiles allows the incorporation of the values for clothing and furnishing fabrics into calculations for thermal environments, heat losses from rooms, etc. Thermal resistances of layers of fabrics are additive, thus the values for whole clothing assemblies can be calculated. The method of test can be easily adapted to allow for provision of air gaps between layersoffabric. It has been suggested that a simple measurement of thickness provides an adequate measure of the thermal insulation of, say, blankets. This is only acceptable, however, if a common value can be assumed for the thermal insulation per unit thickness. However, the transmission of heat through a textile can occur not only by conduction through the fibres and the entrapped air but also by radiation through the air spaces within the fabric. Because of this, there is a considerable variation in the thermal in- sulation per unit thickness, and thickness is, therefore, an unreliable guide to the warmth provided by, say, blankets even when they are of one type (e.g. raised, cellular or terry). ISO 5085 is published in two parts. This part is suitable for the determination of low thermal resistances, i.e. up to about 0,2 m?. K/W, although it may be usable for values up to about 0,4 m2.K/W. For values greater than about 0,2 m2.K/W, the method specified in ISo 5085-2 is suitable. ili