Identifying key parameters through a sensitivity analysis for realistic hygrothermal simulations at wall level supported by monitored data

The reliability of hygrothermal simulations of building components is key for designing energy efficiency measures, assessing living comfort, and preventing building damage. The model accuracy is related to the reliability of the selection of input parameters. Due to the high uncertainty, the selection of the input values is challenging. This work aims to calibrate a hygrothermal simulation model exploiting monitored values recorded in a case study located in Settequerce (Italy), to understand how close to reality a numerical model can be. Moreover, a sensitivity analysis, based on the Morris method together with a Latin Hypercube sampling, is applied to identify the input parameters that affect most significantly the simulation. The results of the calibration indicated that is possible to obtain reliable outputs by appropriately selecting materials within the database. The sensitivity analysis showed that the relative humidity under the insulation is largely influenced by the water vapor diffusion resistance factor of the plaster, applied during the renovation phase both on the internal and external side. Among the coefficients describing the coupling with the boundary conditions, only the external convective heat coefficient and the coefficient of short-wave solar radiation influence slightly the objective function.

Automated summary

The reliability of hygrothermal simulations for building components is crucial for energy efficiency, living comfort, and preventing damage. The accuracy of the simulation model depends on the selection of input parameters, which is challenging due to high uncertainty. This study calibrates a hygrothermal simulation model using monitored values from a case study in Italy to assess its closeness to reality. The sensitivity analysis identifies the input parameters that significantly affect the simulation. The results show that reliable outputs can be obtained by selecting appropriate materials and indicate the importance of factors like water vapor diffusion resistance and boundary conditions.