Outdoor testing of building and building components under real weather conditions provide useful information about the dynamical performance. Such knowledge is needed for properly characterizing the heat dynamics and provides useful information that can be used eg. to implement energy saving strategies. In order to analyse such tests models and methods for dynamic analysis are required. However a wide variety of models and methods exists, and the problem of choosing the most appropriate approach for every particular case is a non-trivial and interdisciplinary problem.
This paper presents the application of IDENT Graphical User Interface of MATLAB to estimate the thermal properties of building components from outdoors dynamic testing, imposing appropriate physical constraints and assuming linear and time invariant parametric models. Theory is briefly described to provide the background for a first understanding of the used models. The relationship between commonly used RC-network models and the parametric models proposed is deduced. The analysis is generalised for different possibilities in the assignment of inputs and outputs and even multioutput.
Dynamic analysis is very useful to obtain thermal properties of building components. However different methodologies can be applied, and several software tools based on these methodologies are available which application requires certain degree of experience. The main differences between methodologies are the numerical procedure and the model assumed to estimate the required parameters. Different approaches can lead to different and even wrong estimations of the parameters.
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