The study of energy savings in ventilation systems within buildings is crucial. Impinging jet ventilation (IJV) systems have garnered significant interest from researchers. The identification of the appropriate location for the IJV reveals a gap in the existing literature. This research was conducted to address the existing gap by examining the impact of IJV location on energy savings and thermal comfort. A comprehensive three-dimensional CFD model is examined to accurately simulate the real environment of an office room (3 × 3 × 2.9 m³) during cooling mode, without the application of symmetrical plans. Four locations have been selected: two at the corners and two along the midwalls, designated for fixed-person positions. The return vent height is analyzed utilizing seven measurements: 2.9, 2.6, 2.3, 1.7, 1.1, 0.8, and 0.5 m. The RNG k–ε turbulence model is implemented alongside enhanced wall treatment. The findings indicated that the optimal range for the return vent height is between 1.7 and 0.8 m. It is advisable to utilize the IJV midwall 1 location, positioned behind the seated individual and away from the exterior hot wall. It is characterized by low vortex formation in the local working zone that contributes to a more comfortable sensation while providing recognized energy-saving potential.

The rapid depletion of fossil fuel reserves and their associated environmental impacts, including global warming, have led to an increased emphasis on waste heat recovery and renewable energy sources. The present research proposes a novel trigeneration system that harnesses solar energy to generate electricity, heating, and cooling for buildings. The research seeks to reduce energy waste and boost system efficiency. In the Kalina cycle, which is combined with the absorption refrigeration cycle, a heliostat-based central receiver with helical coils and Syltherm 800 oil as the solar heat transfer fluid enhances the conversion of solar rays into heat. Extensive parametric research and system modeling were conducted using the Engineering Equation Solver (EES) software, using mass, energy, and exergy equations. Direct normal irradiation (DNI) and coil form (rib height) affect receiver oil temperature using a mathematical model. ANSYS-FLUENT CFD simulations reveal a maximum of 39.4% rise in oil output temperature at 2 mm rib height, 42 mm coil pitch, and 1000 W/m² DNI. The proposed system’s energetic and exergetic evaluations demonstrate that incorporating an absorption refrigeration cycle (ARC) into the Kalina cycle improves its energy and exergy efficiencies by 23.78% and 14.55%, respectively. The exergetic assessment revealed exergy destruction, with the center receiver dissipating the most exergy (22.45%), followed by the heliostat field (11.67%). The examined receiver configuration provides a practical approach for improving the thermal performance of the solar collector and its associated system. The proposed system supports sustainable development by producing cleaner energy of various types to meet societal needs.

Z- and U-type parallel pipe network configurations are widely used in engineering applications such as solar collectors, fuel cells, microchannels, spargers, and irrigation systems. Although the Z configuration is more commonly employed, the U configuration may provide advantages under specific operating conditions. This study presents a comparative analysis of the two configurations in terms of flowdistribution uniformity and pressure drop. A three-dimensional computational fluid dynamics (CFD) model was developed to simulate realistic solar collector conditions, including both fluid and solid domains together with detailed inlet and outlet junctions. The system consists of manifolds and headers with a diameter of 20 mm and a length of 1150 mm, connected to ten parallel tubes of 7 mm diameter and 1780 mm length. The analysis was conducted over a wide range of inlet Reynolds numbers (Re_D = 100–5000) to represent diverse practical operating conditions. The CFD model was validated against experimental data from the literature and showed good agreement. Flowdistribution uniformity was evaluated using two quantitative indicators. The results show that flow maldistribution increases with Reynolds number in both configurations; however, the U configuration exhibits significantly improved flow uniformity at higher Reynolds numbers. In addition, both configurations exhibited comparable pressure drop characteristics over the investigated operating range. The findings suggest that the U configuration is better suited to high-flow-rate applications that require improved hydraulic and thermal uniformity, while the Z configuration remains effective at lower Reynolds numbers.