RT Journal Article
T1 Estimation of thermal resistance and capacitance of a concrete wall from in situ measurements: 												A comparison of steady-state and dynamic models
A1 Arregi, Beñat
A1 Garay-Martinez, Roberto
A1 Ramos, Juan Carlos
AB There is a growing interest in characterising the thermal performance of building envelopes when exposed to realistic weather and indoor conditions. In this study, data from a full-scale test of four uninsulated concrete panels is analysed using (1) a steady-state model as per the standard average method, (2) a dynamic lumped resistance–capacitance model with a stochastic method, and (3) a dynamic distributed capacitance model based on an analytical solution. These have been favoured over purely data-driven methods, since their physical formulation allows the characterisation of thermal capacity alongside the usual thermal resistance. The models are applied to different data subsets, sampling times and campaign lengths. For the sole estimation of thermal resistance, winter conditions with constant indoor heating allow campaign lengths around 72 h. For a strong indoor-outdoor temperature difference (e.g. 10 °C) steady-state models provide reliable estimates, and lumped capacitance models are found to suit lower temperature differences or less stable conditions. However, for estimating thermal capacity, fluctuating indoor and outdoor temperatures are preferred and only the distributed capacitance model provides consistent estimates for different time steps and data subsets. The present work might be helpful in establishing future guidelines for the use of dynamic methods with physical interpretation, presenting a case study of a simple well-known wall facing a variety of winter and summer conditions. It might also provide a basis for further research, extending the application of these models to more complex multi-layer walls and/or for the assessment of design scenarios including thermal insulation.
SN 0378-7788
YR 2023
FD 2023-10-01
LA eng
NO Arregi , B , Garay-Martinez , R & Ramos , J C 2023 , ' Estimation of thermal resistance and capacitance of a concrete wall from in situ measurements : A comparison of steady-state and dynamic models ' , Energy and Buildings , vol. 296 , 113393 . https://doi.org/10.1016/j.enbuild.2023.113393
NO Publisher Copyright: © 2023
NO The experimental campaign featured in this study has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement ID 637138. This paper reflects only the authors’ views and neither the Agency nor the Commission are responsible for any use that may be made of the information contained therein. The experimental campaign featured in this study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement ID 637138. This paper reflects only the authors’ views and neither the Agency nor the Commission are responsible for any use that may be made of the information contained therein.
DS TECNALIA Publications
RD 1 sept 2024