ÖNORM EN 1934

This standard establishes the principles and criteria to be complied with for the determination of the laboratory steady-state heat transfer properties of masonry walls in a hot box by means of a heat flow meter mounted on one face of the masonry wall to be tested (i.e. the test specirnen). It describes the apparatus, measurement technique and necessary data reporting. It does not, however. specify a particular apparatus design since requirements vary particularly in terms of size, and also to a lesser extent in terms of operating conditions. The property that is rneasured is the surface-to-surface thermal resistance of the specimen, provided that the metering section of the heat flow meter Covers a representative portion of the specimen, and the homogeneity criteria of 6.2.1 are met. From these measurements the thermal resistance for application in buildings is derived. The thermal transmittance of a masonry wall can then be calculated from this value with standardized surface coefficients. This standard is applicable to measurements on both dry and moist specimens, provided that the conditions indicated in 5.3.3 are met. The influence of moisture content on the thermal properties of masonry can be taken into account by measurements at different moisture contents of the specimen in the range of the practical moisture content including the dry state, which corresponds to the most frequent testing condition. The method is also suitable for horizontal elements such as ceilings and floors.