Ce travail concerne une étude expérimentale du comportement hygrothermique de matériaux bio-sourcés sous la forme de briques de terre comprimée (BTC) et de briques de terre stabilisée (BTS). Nous avons déterminé les propriétés thermo-physiques et les isothermes de sorption de ces matériaux et évalué l'influence de l'ajout de stabilisants chimiques (ciment et chaux), sur leurs conductivités thermiques et leurs capacités hygroscopiques. Cette étude est complétée par une modélisation et une simulation numérique des transferts de chaleur et de masse dans une cavité ventilée dont l'une des parois verticales est composée de BTC. Les transferts hygrothermiques dans la paroi, assimilée à un milieux poreux, et dans la cavité ventilée sont décrits respectivement par le modèle de Luikov et les équations classiques de la convection mixte. Ces équations de transferts sont résolues par une méthode implicite aux différences finie, la méthode itérative de Gauss-Seidel et l'algorithme de Thomas. Nous avons analysé l'influence de la température, de l'humidité relative et de la vitesse de l'air ambiant, la densité du flux de chaleur appliqué sur la face externe de la paroi ainsi que la nature du matériau bio-sourcé sur les transferts hygrothermiques dans cette paroi et l'écoulement d'air dans la cavité. Les résultats montrent que la stabilisation chimique augmente la conductivité thermique de la BTC et réduit sa capacité de sorption. L'accroissement de la densité du flux de chaleur appliqué sur la face externe de la paroi de BTC provoque une augmentation des transferts de chaleur par mode latent et sensible entre la face interne de cette paroi et l'air qui s'écoule dans la cavité. / This work concerns an experimental study of the hygrothermal behavior of compressed earth bricks (CEB) and stabilized earth bricks (SEB). We determined its thermo-physical properties and sorption isotherms and evaluated the impact of the chemical stabilizers (cement and lime) addition on their thermal conductivities and hygroscopic capacities. This study is complemented by a modeling and numerical simulations of heat and mass transfers in a ventilated cavity one of its vertical walls is composed of CEB. The heat an mass transfers in this wall, assimilated to a porous medium, and in the ventilated cavity are respectively described by the Luikov model and the mixed convection equations. The transfer equations are solved using an implicit finite difference method, the Gauss–Seidel method and the Thomas algorithm. We have analyzed the effects on the heat and mass transfers within this wall and in the cavity of the temperature and relative humidity air, the inlet air velocity in the cavity and the heat flux density applied on the external face of the vertical wall composed of CEB. These results show that chemical stabilization increase the thermal conductivity of CEB and leads to a reduction in moisture sorption capacity. The increase of the heat flux density applied to the external face of the wall composed of CEB leads to an augmentation of the latent and sensible heat transfers between the inner face of this wall and the air flowing in the cavity.

Global warming is one of the biggest challenges today, and the construction sector is one of the main sectors contributing to climate change. Due to this, using environmentally friendly materials in construction is an important decision against global warming. This thesis aims to evaluate the most important building envelope components to achieve a house in Sweden to become near net-zero energy building (ZEB). Due to this, different ecological insulation materials, and window types were presented, analyzed, and evaluated to choose the most energy-efficient alternatives for the Utsikten village project. In terms of reduction of electricity bought, renewable energy on-site photovoltaic (PV) and ground source heat pump systems are used. In this study, numerical simulations for building envelope components such as windows, ground floor, external walls, and roofs were performed to evaluate the thermal performance of the components by IDA ICE and UBAKUS. The primary energy for different building cases has been calculated to evaluate thermal performance and energy classification levels to identify the most environmentally friendly solutions. There is a variation of ecological material for insulation that can be used for different parts of the building envelope. In general, ecological insulation material has less life expectancy but a much lower environmental impact compared to minerals and synthetic materials. However, there are also some limitations to using some ecological insulation materials in the ground construction. This study also shows how several pane glasses, gap dimensions, gas fill gap, and Low-E coating impact the energy performance of the windows and the building. Simple solar PV panel simulation shows that the maximum electricity production on a site is very related to orientation, tilt, and sun exposure. The result of this master thesis shows that it is possible to reach near-net-zero energy building by enhancing building envelope components and using renewable energy sources for heating, cooling, and electricity production.