Sustainability of non-residential buildings and relevance of main environmental impact contributors' variability. A case study of food retail stores buildings

Abstract European tertiary sector represents about 13% of EU-28 final energy consumption. As an example, food retail stores sector amounts about 3% of EU members’ electricity consumption. Furthermore, currently, fluorinated gases, which are the most used refrigerants for space conditioning and refrigeration systems, involve 2% of EU emissions, having risen since 1990 by 60%. Specifically, commercial refrigeration is responsible for 35% of EU-27 CO2-eq emissions related to refrigerants. A methodology based on Life Cycle Assessment standards is presented in this study to assess the energy and environmental implications of non-residential buildings, adapted to particularities of food retail stores buildings, in terms of Primary Energy Demand, carbon footprint and water demand. Relying on a reference building, constructive improvements are tested and evaluated. Then a sensitivity analysis of several configurations of food retail stores are studied considering their building location, refrigerant typology and schedule. Results show that electricity and refrigerants are the main contributors and sensitive to potential improvements. In fact, static calculations reveal that a food retail store may involve, in terms of Global Warming Potential, about 800 kgCO2- eq/m2 year, more than 20 times higher than a regular building. Thus, future scenarios are estimated through a dynamic calculation methodology. Due to optimal dimensioning and configuration of the refrigeration system, together with refrigerant replacement, an 80% of Global Warming Potential minimization can be reached. Furthermore, temporal dynamic assessment can present a variability of environmental impacts estimation from static Life Cycle Assessment of more than 15%, by considering a wider approach towards sustainability assessment of non-residential buildings.