Energy efficiency in the commercial sector. Thermodynamics fundamentals for the energy transition

Any building plays a pivotal role due to its global energy and environmental impact. In particular, food retail trade buildings have a large potential for improvement due to their high energy consumption per unit floor area. The main aim of the present study is to identify, through a systematic literature review, the most mature and promising high energy performance and low greenhouse gas emissions strategies, technologies, and refrigerants, and outline the research trend in food retail buildings. More than 110 studies are collected and analysed to reply to a fundamental question: What are the strategies for refrigeration and other energy systems functional to the energy transition? Results show that many studies focus on the development of improved refrigeration systems setups and configurations using natural refrigerants (mostly CO2) to cut down environmental impact. Other notable strategies concern closed refrigerated cabinets utilization and integration of combined cooling, heat, and power systems and photovoltaic as renewable energy sources. Implementation of LED lighting and proper management and control of the complex connection between plants are other important solutions. This review stresses these potential future directions for research and technological advancements to facilitate the achievement of green energy transition and energy environmental sustainability.