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This work analyzed the thermal behavior of an existing building, considering different retrofitting strategies. The methodology starts with an in-situ survey that allowed for obtaining information about occupation, work schedules, envelope materials, lighting, and equipment, which was vital to develop an energy model of the building. Then, the thermal analysis, employing simulations, demonstrates a higher relevance of heat flows through the building's envelope than internal loads and higher cooling rather than heating demands. Afterward, several retrofit strategies focusing on modifying architectural elements were assessed. Finally, these strategies were compared based on their impact on the air-conditioning energy demand. A systematic review identified a lack of studies relating certification and energy policies to buildings retrofitting. Therefore, we assessed the energy performance of the building, when modified to meet the baseline requirements set on the Chilean certification requirements for sustainable buildings, to verify if the certification is a suitable method to assess the energy efficiency of an office building. Although the study only involves a single building, it aims to illustrate identified limitations using the energy policies for Chilean public buildings. The Chilean certification for sustainable buildings seems not to be suitable for the evaluation of energy consumption for the retrofit of existing buildings. Although this study does not demonstrate general trends, it presents a precedent for subsequent studies to evaluate the relevance of the Chilean certification guidelines. [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]

The application of phase change materials (PCM) in the thermal envelope of buildings has proven to be an alternative to reduce energy consumption and to improve thermal comfort conditions. The present work evaluates the thermal behavior of gypsum boards modified with a microencapsulated PCM (mPCM) in a cubic test enclosure, considering the climatic conditions of Santiago de Chile in the September–November period of 2017. The design of the test enclosure was performed considering the minimization of parameters that affect the variation of its inner temperature and favoring the heat flow through the gypsum boards. Experimentally, the results reflect the main effects of the implementation of a mPCM, among which the displacement of the maximum heat load and the decrease in the daily oscillation of the internal temperature of the test enclosure (up to 2 °C) stand out. In addition, the mPCM modified gypsum board was thermally characterized to carry out a thermal simulation of the enclosures using EnergyPlus™. The obtained numerical results agree with those obtained experimentally, including the behavior of the transient heat flux through the gypsum boards. Moreover, it was found that considering a null infiltration rate gives place to unrealistic results, suggesting that this parameter should be controlled. [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]