Measurements of thermal insulation performance: The challenge of the next decade

Abstract

The past two decades have stimulated significant growth both in thermal insulation materials and product development and in their use for new and different applications. These activities have had a resultant impact both on existing methods of measurement of relevant thermal properties and on the development of new or modified measurement techniques. Various examples of present measurement technologies applicable to the new materials and applications are discussed in relation to the current state of the art. These include (1) measurements on very high-thermal resistance per unit thickness insulation systems for appliances and buildings, (2) improvements in current standard methods of test, particularly in speed of operation and relevance to application, and (3)in situ and field measurements. The discussion includes examples of current limitations. These relate particularly to accuracy, especially at elevated temperatures, product variability, a need for relevant transient techniques, and very urgent requirements for reference materials and transfer standards. As a result, recommendations are proposed in the hope that they will stimulate necessary research and development work in the next decade.