Characterization of hygrothermal transfers in the unfired earth

Abstract

In front of the building energy issues and environmental impact bound, it appears that the earth envelopes are a promising track in terms of improving thermal comfort, indoor air quality, energy consumption and indoor humidity regulation. For this purpose, a characterization of hygrothermal transfers in the unfired earth was been conducted with experimental and numerical approaches. Thus, the studies at the material and wall scales were necessary to check dissociate and coupled hygrothermal behaviour. The material scale has been used to characterize properties related to heat and mass transfers. The hygrothermal coupling has been the subject of a specific study via a dual-climate test chamber at an earth wall scale. Finite Differences (FD) and Finite Elements (FE) implementations have resulted in a detailed analysis of transfers across the tested earth wall with a reduction work of order required to limit the calculation time. Emphasis is placed on the effects of moisture in the hygrothermal transfer in order to validate a digital tool developed in this work.