Life cycle analysis of the environmental impact of different cabinet designs

Abstract

The design of refrigerated display cabinets greatly affects their subsequent environmental impact. To control this impact, a designer must primarily consider the operating efficiency of a cabinet. However, less account is taken of the materials used to make the cabinet, nor the construction techniques used. These both have a significant effect on the environmental impact of different cabinets outside the use phase of their life cycle. Initial construction impact, remanufacturability and recyclability are all affected. Given the ubiquity of the display cabinet in the retail sector, it is important to assess their lifetime impact in toto. This is particularly so with the increasing implementation of the WEEE directive in member states. Three typical refrigerated display cabinets are examined in this paper, all offering the same function, but manufactured with quite different constructions and materials. The mass of materials in each cabinet was determined experimentally and the methods of assembly examined. The stages in the life of each cabinet were then modelled and life cycle analyses performed. To compare the efficiency of the cabinets in terms of their environmental impact, the Eco Indicator Points/litre of refrigerated space/day were determined in each case. When combined with the energy performance (kWh/litre/day) this provides a good measure of the overall environmental impact of a cabinet and a way of choosing between different models that nominally provide the same refrigeration function. Different end of life scenarios, and improvements in the choice of materials, were also investigated depending on the type of construction. INTRODUCTIONRefrigerated display cabinets are used worldwide to sell chilled food and beverages in supermarkets and smaller stores. The subject of this study is the open-fronted vertical display cabinet which offers the advantage of unimpeded selection and access to the products by a customer. This free access is also associated with the high energy use of this type of cabinet, compared with those cabinets fitted with doors or other thermal barriers. It is debatable whether these open-fronted cabinets would be introduced now in the current climate of high energy prices and concerns for global warming. However, given their continuing use, it is useful to look at ways of reducing their environmental impact. The particular type of cabinet examined in this paper is the integral cabinet, i.e. the refrigeration system and defrost water disposal are all provided within the cabinet itself, in contrast to the more usual remote systems of large supermarkets, serviced by central chilling plant. Integral cabinets have the advantage of simplifying changes in a store's layout, reducing the potential for a large loss of refrigerant inventory, and often providing a better balance between heating and cooling in a store. However, they usually operate with lower efficiency than their larger, remotely serviced counterparts.

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

“…Refrigerated cabinets and shelves' embodied carbon, between 280 and 620 kgCO2-eq/m regarding length of display case [44], is not taken into account in this study due to: i) it has been demonstrated that their use phase represents more than 90% of their environmental impacts (approx. 93% [45], 95% [46]) and ii) they may represent less than 0.04% of building's total GWP. Furthermore, the embodied primary energy corresponding to the addition of glass doors would possibly represent less than 2% of the energy savings related [43].…”