Abstract
The determination of the energy consumption of a building requires the computation of the coupled heat and mass transfers inside the wall. The existing models require the determination of the hygrothermal properties of the materials, and of the boundary and initial conditions, prior to computing numerically the temperature and vapour fluxes and the energy and mass balance of the building. However, the experimental measurements do not give accurate values, yielding a wrong estimation of the energy consumption. In order to determine the influence of the uncertainties on the values of the input parameters of the Kunzel model, we carried out a local sensitivity analysis (LSA) by varying by 5% the hygrothermal properties of the materials, the surface transfer coefficients and the initial conditions. The results of the LSA are treated by means of quartile boxes in order to identifiy the most influent parameters. The LSA is applied to two walls made of highly porous and hygroscopic materials: limestone and hemp concrete. The results show that the surface transfer coefficients and the adsorption isotherm are the most influential parameters. However, the conclusions are slightly different between the two materials, because of differences in the relative importance of transfer phenomena.
Acknowledgements
The authors want to thank the French Environment and Energy Management Agency for funding this thesis.
Disclosure statement
No potential conflict of interests was reported by the authors.