Felipe Mercês Biglia

Buildings account for a significant portion of global energy consumption, estimated at 30-40%, and also contribute to greenhouse gas emissions. Energy consumption in a building is mainly thermal (natural gas) and electrical. This energy is usually used for heating water, cooking, illumination, ventilation and air conditioning, powering appliances, floor heating, and other activities. These activities were examined, and their substitution by solar-based energy sources was reviewed. To achieve this objective, an extensive literature review across Scopus, Direct Science, and Web of Science in relevant areas, including building energy needs, thermal and visual comfort, and construction materials and components, was conducted. Innovative construction materials, including mortars, bricks, concrete, and components such as Trombe walls, can enhance thermal efficiency and thermal comfort. Solar energy can replace fossil-based energy for the provision of hot water, and hot fluid for air conditioning absorption chillers systems. Building components such as thermally efficient windows (double-glazed, evacuated, etc.), bright windows, and facades can help maintain a thermally and visually comfortable indoor environment. Electric energy for buildings’ services, such as illumination, ventilation, and other services, can be provided by solar PV panels. The review shows that solar energy can significantly contribute to decarbonizing buildings’ energy needs, maintaining passive thermal and visual comfort, and reducing emissions. The review indicates that a solar air conditioner with a 12,000 BTU cooling capacity can save 8-28% of energy and reduce emissions by 7.74-28.27%. It also showed that selecting windows and facades is a critical issue. A comparison of the energy-saving of thermo-chromatic, double-glazed, and clear glass windows indicated a reduction of 8.91% to 10.96% in energy consumption due to double-glazed windows and a reduction of 20.22% to 24.19% due to thermo-chromatic windows. Smart windows with photovoltaic electrochromic (PV-EC) enabled a useful daylighting illumination of about 75.26% and energy saving of about 15.79% compared to ordinary windows. It is recommended that applications such as hot water, water distillation, illumination, electricity, and air conditioning be powered by solar energy. In the construction of buildings, thermally efficient materials and components should be prioritized. To promote building decarbonization, it is necessary to reduce the cost of materials, create financial incentives and low-interest grants for retrofitting, and create public policies to promote solar-based energy applications in buildings.

The efficient recovery of waste heat is essential for improving sustainability in industrial and urban energy systems. This study presents the experimental evaluation of a passive heat recovery unit composed of finned thermosyphons and Bismuth Telluride (Bi₂Te₃) thermoelectric generators (TEGs). The primary objective was to characterize its simultaneous thermal recovery and electrical generation capabilities under airflow and temperature conditions simulating low-grade industrial exhaust streams. The system was tested in an open-loop wind tunnel simulating exhaust gases under air velocities of 0.6, 1.1, and 1.7 m/s. Heat was transferred to the TEGs through finned thermosyphons, enabling power generation via the Seebeck effect. The passive heat exchange mechanism successfully recovered up to 250.9 W of thermal power, preheating the inlet air by a maximum of 9.5 °C with a peak thermal effectiveness of 44.4%. Simultaneously, the system achieved a maximum temperature difference of 30.0 °C across the thermoelectric modules, generating a total electrical power of 163.7 mW (81.8 mW per TEG). This dual-purpose operation resulted in a maximum overall first-law efficiency of 9.38% and an electrical power density of 52.20 W/m² from the low-grade thermal stream. These results confirm the technical feasibility of this compact, passive, and maintenance-free design, highlighting its potential for integration into applications like district heating or industrial ventilation, where balancing thermal and electrical outputs is crucial.

Anais do Congresso Internacional de Engenharia Mecânica e Industrial (2764-4294) - Estudo De Caso Da Utilização De Termossifões Como Alternativa De Pré-Resfiadores Aplicados À Indústria De Laticínios

Anais do Congresso Internacional de Engenharia Mecânica e Industrial (2764-4294) - Análise Fluidodinâmica E Térmica Do Escoamento Laminar Sobre Uma Placa Plana: Comparativo Das Soluções Numéricas Obtidas Via Openfoam E Ansys/Fluent

Anais do Congresso Internacional de Engenharia Mecânica e Industrial (2764-4294) - Estudo Numérico-Experimental Da Formação De Gelo Poroso Em Placas Planas De Aço Inoxidável

Uma Revisão Sistemática da Literatura sobre a Utilização de Nanofluidos em Trocadores de Calor / A Systematic Literature Review about the use of Nanofluids in Heat Exchangers