A practical method for in-situ thermal characterization of walls

A practical and fast method for thermal characterization of walls based on complex Fourier analysis is proposed to determine the thermal capacitance (defined as the product of density and specific capacity) and the thermal conductivity for a building wall using the monitored inner/outer surface temperatures and outer heat flux. This method is useful for in-situ determination of walls’ thermal properties in stochastic regimes and therefore does not require any particular constraints in boundary condition.The minimum measurement duration was analyzed by determining the relative deviation between consecutive optimal values for R and C in order to reduce as much as possible the monitoring duration for energy auditors without losing accuracy.