TABLE OF CONTENTS - The Professional Green Building Council

Theme B: Creating a livable, healthy and environmentally viable citiesTable 6: by changing heat exchanger typeDesignheatexchangertypeInitialInvestmentcost(KRW)Operationcost(KRW/Yr)PDCO 2 (PPM)Non-dominatedSolution(Design 8)Total HeatExchanger1,569,700264,780A 700DominatedSolutionSensibleHeatExchanger1,619,700826,450A 700The sensible heat exchanger was not selected as shown in Table 3 for the followingreasons: since a sensible heat exchanger uses a heat exchange component madewith metal, it is more expensive and has lower heat transfer efficiency than a totalheat exchanger which uses a component made with paper. An advantage of thesensible heat exchanger is that it reduces problems associated with a total heatexchanger such as mold growth and dust clogging in the filters, etc because it usesmetal as a heat exchange element. However, these problems in the total heatexchanger can be solved by replacing filters regularly. Be noted that the cost offilter exchange is included in this study. With a given airflow rate, the sensible andtotal heat exchanger provide identical PD and CO 2 concentration. But, the sensibleheat exchanger requires higher initial investment cost and provides lower heatrecovery. Thus, the sensible heat exchanger becomes dominated by the total heatexchanger. Accordingly, the sensible heat exchanger is not selected in this study.4.2 Application in design scenariosIn the previous section, it was shown that all 18 designs were non-dominatedPareto optimal solutions. The advantage of Pareto optimality is that it offers not‘one’ but ‘multiple’ non-dominated solutions, enabling the DM to select his/herpreferred design choice. In other words, there is no need to determine the weightsamong the objective function elements. As mentioned earlier, the weights can varyaccording to the DM’s preference. Since Pareto optimality is not associated withthe issue of weights, the DM is able to select an optimal design of his/her choicefrom Table 3.407