Hygrothermal performance of wood-cement walls across various climate conditions

Abstract

In response to the challenges of natural resource depletion and the need to reduce energy consumption in buildings, the demand for sustainable materials and energy-efficient construction practices has become critical. This study aims to evaluate the hygrothermal performance of walls constructed from wood aggregates-cement concrete and to compare their effectiveness with that of conventional walls under different climates. The numerical model for heat and moisture transfer through wood concrete walls, implemented using MATLAB software, is validated through a long-term in-situ measurement on a wood-cement concrete building over a 12-month period. Monitoring of temperature and relative humidity takes place both inside and outside the building, as well as at three specific positions within the walls. Thermo-physical parameters of wood concrete necessary to feed the model are initially determined through in-lab experimental characterization. Comparisons between the measured and numerical results demonstrate the ability of the adopted ‘reduced heat, air, and mass’ model to accurately replicate the hygrothermal behavior of wood-concrete walls under real climatic conditions. After successfully validating the model, the hygrothermal performance of the wood-cement wall under different climate conditions is evaluated. The assessment incorporates key parameters such as the decrement factor, time lag, and interstitial condensation. Focusing on the center position of the wall, the study demonstrates that the bio-based wall achieves up to 6% more temperature reduction than the conventional wall and maintains more stable RH levels, fluctuating around 70%. Furthermore, no condensation is observed in any of the climates studied, highlighting the material’s suitability for sustainable building designs.