Physical parameters identification of walls using ARX models obtained by deduction

Autoregressive models with exogenous (ARX) are widely used for parameters identification of walls although their parameters do not have a direct physical interpretation. This paper uses measured data and an ARX model, obtained by deduction from a thermal network, for identifying the parameters with physical meaning of a wall tested under real weather conditions. The physical parameters are the U-value, the dynamic solar energy transmittance and the effective heat capacity. The paper presents the whole chain of transformations from thermal networks to ARX models for demonstrating that the procedure used for recovering the physical parameters guarantees their unicity. The estimations of the physical parameters are presented together with their uncertainties.