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Renewable energy has become a relevant alternative to solve energy and environmental problems worldwide. Characterization of geothermal resources is fundamental for an efficient and sustainable extraction of heat. In this study, thermal conductivity, λ , volumetric heat capacity, C, and thermal diffusivity, α , of two soils from Chile, namely Bío Bío sand and Maicillo residual soil, were analysed. Bío Bío sand is a uniform and clean sand that mainly consists of basaltic particles, whereas Maicillo soil is a silty and clayey sand with a high quartz content. Samples were tested with a thermal needle probe at varying water contents and densities. Measurements to obtain λ , C and α were undertaken. These results allowed the patterns and relationships between geotechnical and heat transfer parameters to be analysed. It was found that dry soil conditions led to the lowest values of λ , while saturated soil conditions led to the highest values. Moreover, Maicillo soil has higher capabilities to transfer heat than Bío Bío sand, and can reach up to 50% greater λ for dense soil and saturated conditions. This is due to its quarzitic and clayey mineralogy and non-uniform grain-size distribution. The results from this research represent an important contribution to industrial applications. [ABSTRACT FROM AUTHOR]

The inadequate use of passive thermal conditioning alternatives, such as phase change materials (PCM), in Chile, despite the climatological advantages in various regions of the country and the need to improve thermal comfort indexes in many houses and buildings, is mainly due to cultural and economic reasons. Passive thermal conditioning measures entail economic benefits and an improvement in the quality of life. However, it is perceived as a luxury and not as an investment by many Chileans. We propose an optimized implementation methodology for PCM using a house belonging to the National Housing Monitoring Network (ReNaM) in Santiago, Chile. The strategic use of PCM is based on thermal comfort and occupancy. The proposed methodology improves the thermal comfort indexes and reduces the thermal loads of the building, resulting in lower energy consumption and CO 2 emission. The proposed methodology also considers economic aspects to promote PCM as a passive alternative for thermal conditioning. [Display omitted] • A methodology to implement PCM using actual data of dwellings in Chile was used. • Walls with higher gains of rooms with higher thermal stress hours were intervened. • Thermal stress hours are reduced by 11%–23% after using PCM. • PCM implementation decreases the cooling load by 45.4%–60.3% in the summer period. • A payback period of 9.64 years is determined after implementing the PCM. [ABSTRACT FROM AUTHOR]

• LHTES system was implemented along with a conventional chiller system of a building. • Strategies of operation were assessed by computational simulation with EnergyPlus. • A hybrid operation strategy was evaluated, and the cooling loads were obtained. • LHTES reduces by 7.8% the cooling energy consumption of the cooling system. Energy consumption of commercial buildings has increasingly gained attention worldwide, because of its significant electricity consumption and peak power demand. Chiller plants are mostly used in commercial buildings to generate cold water for air conditioning. However, because the chiller plants and the refrigeration systems tend to be oversized with respect to their critical design load conditions, they certainly lead to higher energy consumption than a properly sized chiller plant. One possible way to reduce the power consumption and redistribute energy use is through the integration of latent heat thermal energy storage (LHTES) systems with air-cooling system in buildings. In the present work, a LHTES system based on ice is implemented along with a conventional chiller system of an existing commercial building located in Santiago, Chile. Different strategies of operation in a design day are assessed by computational simulation with EnergyPlus. A hybrid operation strategy is evaluated for the hottest summer week, and the results of the cooling loads are obtained. Finally, we founded that the implementation of a LHTES reduces by 7.8% the cooling energy consumption of the cooling system during the analyzed period. [ABSTRACT FROM AUTHOR]