Eco Audit White Paper. - Granta Design

60% or more of the energy—often much more.If large energy savings are to be achieved, it isthe dominant phase that becomes the firsttarget since it is here that a given fractionalreduction makes the biggest contribution. Thesecond: when differences are as great asthose of Figure 4, great precision is notnecessary—modest changes to the input dataleave the ranking unchanged. It is the natureof people who measure things to wish to do sowith precision, and precise data must be theultimate goal. But it is possible to moveforward without it: precise judgments can bedrawn from imprecise data.3. Base the subsequent action on theenergy or carbon breakdown.Figure 5 suggests how the strategy can beimplemented. If material production is thedominant phase, then minimizing the mass ofmaterial used and choosing materials with lowembodied energy are logical ways forward. Ifmanufacture is an important energy-usingphase of life, reducing processing energiesbecomes the prime target. If transport makesa large contribution, then seeking a moreefficient transport mode or reducing distancebecomes the first priority. When the usephasedominates the strategy is that ofminimizing mass (if the product is part of asystem that moves), or increasing thermalefficiency (if a thermal or thermo-mechanicalsystem), or reducing electrical losses (if anelectro-mechanical system). In general thebest material choice to minimize one phasewill not be the one that minimizes the others,requiring trade-off methods to guide thechoice. A full description of these and othermethods for materials selection can be foundin reference (2).Implementation requires tools. Two sets areneeded, one to perform the eco auditsketched in the upper part of Figure 5, theother to enable the analysis and selectionsketched in the lower part. The purpose of thiswhite paper is to describe the first: the EcoAudit Tool.4. The Eco Audit ToolFigure 6 shows the structure of the tool. Theinputs are of two types. The first are drawnfrom a user-entered bill of materials, processchoice, transport requirements and duty cycleFigure 5. Rational approaches to the eco design of products start with an analysis of the phase of lifeto be targeted. Its results guide redesign and materials selection to minimize environmental impact.The CES EduPack Eco Audit Tool 4 © 2012, Granta Design