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Abstract Worldwide, the residential buildings are consuming a considerable amount of energy. The high potential of buildings towards energy efficiency has drawn special attention to the passive design parameters. A comprehensive study on optimal passive design for residential buildings is presented in this paper. Twenty-five different climates are simulated with the aim to produce best practices to reduce building energy demands (for cooling and heating) in addition to the life-cycle cost (LCC). The occupants' adaptive thermal comfort is also improved by implementing the appropriate passive cooling strategies such as blinds and natural ventilation. In this respect, the implemented methodology is composed of four phases: building energy simulation, optimization, Multi-criteria Decision Making (MCDM), sensitivity study, and finally an adaptive comfort analysis. An optimal passive solution of the studied building indicates the potential to save up to 54%, 87% and 52% of the cooling demands (Qcool), heating demands (Qheat) and LCC respectively with respect to the initial configuration. The obtained optimal passive parameters are validated with the National Renewable Energy Laboratory NREL benchmark for low energy building's envelope. Additionally, the integrated passive cooling strategies have demonstrated its competency since it leads to a significant overheating decrease. Highlights • Residential building's passive design parameters are optimized. • Effect of different climates of Köppen Geiger classification is studied. • Thermal comfort and energy performance of the case-studies are significantly enhanced. • Passive cooling strategies lead to adequate thermal comfort and fewer cooling systems. [ABSTRACT FROM AUTHOR]

Enhancing efficiency, meeting environmental standards, and preserving fuel resources are highly important objectives in power generation systems, at a time where world is endangered by several energetic, environmental, and health crises. Thus, better designs are constantly sought to increase the performance of such systems. In this study, an environment friendly trigeneration system based on solid oxide fuel cell (SOFC) is selected and designed for domestic applications. Negligible emissions are thus recorded as the SOFC is fueled solely by hydrogen. The system is modeled following three steps: the energy simulation of residential building to determine its demands, the system’s prime mover–SOFC, and the trigeneration recovery system ensuring the maximum coverage of heating, cooling, and domestic hot water loads respectively. The system is then evaluated under the 4-E assessment criteria: energy, exergy, economy, and environment. Depending on these criteria, the system is multi-objectively optimized. Two operation strategies are adopted: off-grid following electrical load and on-grid base load operations. Optimization results show that the trigeneration system is energetically and economically superior and performs well under both strategies. The maximum energy and exergy efficiencies (65.2% and 45.77%) and minimum system cost rate (22.2 cents/kWh) are obtained under on-grid base load operation. [ABSTRACT FROM AUTHOR]

The hybrid cooling system has proved to be an energy saving technology for building air conditioning. Numerous systems combining different cooling processes or cooling machines have been proposed and investigated in the literature. A properly selected hybrid cooling system offers a great reduction in energy consumption and a coefficient of performance improvement varying according to different climates and system designs. This paper provides a detailed review of existing hybrid cooling systems with their corresponding individual cooling machines. A brief state of the art of the most common individual cooling systems in hybrid cooling for building use is firstly presented. Then, the hybrid cooling systems are classified into five main categories according to the combination of cooling processes or machines: Vapor compression based cooling, absorption based cooling, adsorption based cooling, desiccant-evaporative and multi-evaporator cooling. In each category, the studied configurations and the benefits of each hybridization method are presented. It is found that each hybrid system combines the advantages of the different cooling processes used. However, a hybrid system could have a negative repercussion if it does not match the climatic zone where it will be used. Consequently, a selection scheme to recommend the best hybrid cooling system for minimum energy consumption and pollution emissions in buildings according to different parameters is proposed. [ABSTRACT FROM AUTHOR]