1 Sinusoidal response measurement procedure for the thermal performance assessment of PCM by means of 2 Dynamic Heat Flow Meter Apparatus 3 Stefano Fantucci a , Francesco Goia b* , Marco Perino a , Valentina Serra a 4 a Department of Energy, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy 5 b Department of Architecture and Technology, Faculty of Architecture and Design, NTNU, Norwegian University of 6 Science and Technology, Alfred Getz vei 3, 7491 Trondheim 7 * Corresponding author: Francesco Goia 8 E-mail addresses: francesco.goia@ntnu.no 9 10 Abstract 11 The implementation, in Building Performance Simulations (BPS) tools, of robust models capable of simulating the 12 thermophysical behaviour of a Phase Change Material (PCM) represents a fundamental step for an appropriate thermal 13 evaluation of buildings that adopt PCM-enhanced envelope components. 14 Reliable and robust measuring procedures are essential, at a material and component level, to provide experimental data 15 for the empirical validation of software tools. The traditional laboratory tests that are generally used for the validation of 16 models present some limitations, because PCMs are usually subjected to conditions that may be very different from the 17 real boundary conditions of the building components in which PCMs are applied. Furthermore, in many experimental 18 full-scale mockups, the relatively small quantity of installed PCM and the combination of several thermal phenomena do 19 not allow software tools to be tested in a reliable way. 20 In this paper, an experimental procedure, based on a modified Heat Flow Meter Apparatus, has been developed to test the 21 behaviour of PCM-enhanced components; the procedure, which is based on the measurement of the sinusoidal response, 22 has been set up to provide data for the comparison and testing of numerical models and of BPS tools. Moreover, general 23 indications and guidelines are provided to solve some issues related to building specimens that contain bulk PCM in order 24 to obtain a more accurate measurement of their performance.// 25 The experimental results presented in this paper were obtained from two different bulk PCMs (organic and inorganic). It 26 was found that it is important to evaluate different PCM typologies and different thermophysical boundary conditions, 27 including partial and full phase transitions, to test simulation codes that implement PCM modelling functions. In fact, 28 some phenomena, such as hysteresis and subcooling effects are more evident when partial phase transition takes place. 29 The results related to the characterization of the thermal conductivity of a paraffin-based PCM have shown a significant 30 increase (up to 42%) of the equivalent thermal conductivity from a solid to a liquid state, with an upward heat flux, thus 31 highlighting that further investigations and improvements are needed to measure the equivalent thermal conductivity in 32 the different PCM phases. 33 Keywords: Dynamic heat flow meter, phase change materials, experimental analysis, building components, building 34 energy simulation, model validation. 35 Original paper available at:https://doi.org/10.1016/j.enbuild.2018.11.011 Disclaimer: This manuscript is a pre-print version of the research article. Small differences in terms of wording may occur between this version and the original version of the article because of the final proofreading occurred after the pre-print version.