Determination of the Thermal Resistance of Pipe Insulation Material from Thermal Conductivity of Flat Insulation Products

New European product standards now include a mandatory requirement for manufacturers to declare the temperature-dependent thermal conductivity for each insulation used in building equipments and industrial installations. For pipe insulation systems, the measurement is usually performed by a standard pipe test method, in which the value on a large temperature range is integrated to reduce temperature range and improve temperature measurement control. The alternative proposed in this article consists in determining the thermal conductivity of a pipe insulation system from the results measured on a flat slab specimen. The protocol used in this study consists in collecting the thermal conductivity data and then in fitting the curve with a polynomial regression, using a leastsquare method. The comparison between the pipe insulation specimen and the flat slab product is then done at a specified temperature using the extrapoled polynomial. The methodology is illustrated with a mineral wool over a large range of temperature.