Steady-state heat transfer properties may be measured by a number of standardized test methods: the choice of the most appropriate method depends on specimen characteristics. BS EN 12664 covers the guarded hot plate and the heat flow meter methods only.
BS EN 12664 specifies principles and testing procedures for determining, by means of the guarded hot plate or heat flow meter methods, the thermal resistance of test specimens either in the dry state or conditioned to equilibrium with moist air, having a thermal resistance of not less than 0,1 m2·K/W and a (hygro)thermal transmissivity or thermal conductivity up to 2,0 W/(m·K).
Note1: BS EN 12664 does not supply general guidance and background information (e.g., the heat transfer property to be reported, product-dependent specimen preparations, suggested materials for vapour tight envelopes when testing moist specimens, procedures requiring multiple measurements, such as those to assess the effect of specimen non-homogeneities, those to test specimens whose thickness exceeds the apparatus capabilities, and those to assess the relevance of the thickness effect). Due to these limitations, BS EN 12664 shall only be used in conjunction with the product standard relevant to the product to be tested.
Note2: BS EN 12664 does not cover measurements on thick products of high and medium thermal resistance.
BS EN 12664 on the thermal performance of building materials and products is useful for:
BS EN 12664 provides general information on the apparatus, all mandatory limits for the equipment design and operation, and the specification of the testing procedure, for dry and moist specimens, with medium and low thermal resistance, described in relevant technical specifications (e.g., a European product standard or a European technical approval)
BS EN 12664 also includes examples of equipment designs that meet the apparatus requirements, so that the assessment of the accuracy of equipment designed accordingly does not need an error analysis but only the equipment performance check.
Overall, the guidelines of BS EN 12664 enable you to perform the guarded hot-plate and heat flow-meter methods accurately and determine the thermal performance of low thermal resistance building materials.
EN 12664:2001