DETAILED TECHNICAL REPORT POTENTIAL OF ENERGY EFFICIENCY IN EXISTING … · 2018-10-04 · buildings and by improving the energy utilization efficiency in the operation of existing

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DETAILEDTECHNICALREPORTPOTENTIALOFENERGYEFFICIENCYINEXISTINGBUILDINGJKRHEADQUARTERSBLOCKF,JALANSULTANSALAHUDDIN,KUALALUMPUR.

Preparedby:CKTANG,GBEETSDNBHDEmail:[email protected]

December2011

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FOREWORDThistechnicalreportispreparedunderthescopeofBuildingSectorEnergyEfficiencyProgram(BSEEP)forMalaysiainNovembertoDecember2011.

BuildingSectorEnergyEfficiencyProject (BSEEP)has for itsgoal thereduction in theannualgrowthrateofGHGemissions fromtheMalaysiabuildingssector.Theprojectobjective is theimprovementoftheenergyutilizationefficiencyinMalaysianbuildings,particularlythoseinthecommercial and government sectors, by promoting the energy conserving design of newbuildings and by improving the energy utilization efficiency in the operation of existingbuildings.Therealizationofthisobjectivewillbefacilitatedthroughtheremovalofbarrierstotheuptakeofbuildingenergyefficiencytechnologies,systems,andpractices.

Thisreport ispreparedbyCKTangofGBEETSDNBHDwhomwasemployedasashorttermBSEEPconsultantfromNovembertoDecember2011forthiswork.

Theviewsexpressedinthisdocument,whichhasbeenreproducedwithoutformalediting,arethoseoftheauthorsanddonotnecessarilyreflecttheviewsoftheneitherJKRnorGovernmentofMalaysianorUNDP.

CKTANGGBEETSDNBHDZehnBukitPantaiA‐10‐3,JalanBukitPantai,59100KualaLumpurMalaysia.Email:[email protected]

gBEET

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TABLEOFCONTENTSForeword.............................................................................................................................................................................2

ExecutiveSummary.........................................................................................................................................................6

1.Introduction................................................................................................................................................................11

1.1BuildingEnergySimulation..........................................................................................................................12

1.2WeatherData......................................................................................................................................................14

1.3BasicInputData.................................................................................................................................................15

1.4OperationDailyandWeeklyProfiles........................................................................................................17

2.BaseSimulationModelvsMeasuredData......................................................................................................24

2.1EnergyResultsComparison..........................................................................................................................24

2.2TemperatureandHumidityComparison................................................................................................33

2.3DataCenterInBlockF.....................................................................................................................................35

3.EnergyEfficiencyRetrofitsPotentialforBlockF........................................................................................37

Electricitytariff.....................................................................................................................................................37

3.1BaseCase0:TheComfortableBaseCaseScenario..............................................................................38

3.2BaseCase0:As‐IsBaseCaseScenario......................................................................................................39

3.3Case1:FixAir‐TightnessofBlockF...........................................................................................................40

3.4Case2:BetterComfort....................................................................................................................................41

3.5Case3:SmallPowerReductionatNight..................................................................................................42

3.6Case4:OfficeElectricalLightingEfficiency............................................................................................44

3.7Case5:LightSwitchesand/orOccupancySensorinOfficeSpace................................................45

3.8Case6:OccupancySensorinToilets.........................................................................................................47

3.9Case7:LiftEfficiency.......................................................................................................................................48

3.10Case8:CO2SensorwithMotorisedFreshAirDamper...................................................................49

3.11Case9:BetterComfortAgain,ReduceRoomTemperature..........................................................50

3.12Case10:ReduceChilledWaterFlowRate............................................................................................51

3.13Case11:IncreaseChilledWaterSupplyTemperatureto9°C......................................................53

3.14Case12:HighΔTChilledWaterSystem................................................................................................54

3.15Case13:FixDuctLeakages,RebalanceAirFlow...............................................................................56

3.16Case14:IncreaseTemperatureSet‐Point............................................................................................57

3.17Case15:ReduceAHUSupplyAirFlowRate........................................................................................58

3.18Case16:LowLostAirFilters.....................................................................................................................60

3.19Case17:FanEfficiency.................................................................................................................................62

3.20Case18:VAVSystem,OffCoilTemp14°C............................................................................................63

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3.21Case19:VAVSystem,OffCoilTemp16°C............................................................................................65

3.22Case20:IncreaseLiftLobbyTemperatureto26.5°C......................................................................67

3.23Case21:ChillerEfficiency...........................................................................................................................68

3.24Case22:VariableSpeedChiller................................................................................................................70

3.25Case23:CondenserFlowRate2.5gpm/ton.......................................................................................72

3.26Case24:CondenserFlowRate2.0gpm/ton.......................................................................................74

3.27Case25:Primary/SecondaryChillWaterFlow.................................................................................76

3.28Case26:PrimaryVariableChillWaterFlow.......................................................................................77

3.29Case27:ChilledWaterPumpEfficiency...............................................................................................78

3.30Case28:CondenserWaterPumpEfficiency........................................................................................80

3.31Case29:PumpMotorEfficiency...............................................................................................................82

3.32Case30:CoolingTowerEfficiency...........................................................................................................83

3.33Case31:VSDonCoolingTower,30.5°C................................................................................................85





3.38Case36:OversizedCoolingTower,26.5°C..........................................................................................92

3.39Case37:200LuxGeneralLighting,19WTaskLight.......................................................................93

3.40Case38:200LuxGeneralLighting,11WTaskLight.......................................................................96

3.41Case39:200LuxGeneralLighting,5WTaskLight.........................................................................97

3.42Case40:DaylightSensorforToilets.......................................................................................................98

3.43Case41:ImprovedAir‐Tightness&AddHeatRecoveryWheel.................................................99

3.44Case42:ChangeGlazingToSingleGlazing‐Clear..........................................................................101

3.45Case43:Daylight3.5mDepthFromFacade.....................................................................................103

3.46Case44:Daylight4.5mDepthFromFacade.....................................................................................105

3.47Case45:PerformanceFilmonGlazing................................................................................................106

3.48Case46:ChangeToPerformanceDoubleGlazing..........................................................................107

3.49Case47:RoofInsulation,50mmPolystyrene...................................................................................108

3.50Case48:RoofInsulation,100mmPolystyrene.................................................................................109

3.51Case49:RoofInsulation,150mmPolystyrene.................................................................................110

3.52Case50:AirTemperatureSet‐Point:24.5°C.....................................................................................111

3.53Case51:ResizeHVACAsPerCurrentNeed......................................................................................113

3.54Case52:ResizeHVAC@12W/m²SmallPower.............................................................................115

3.55Case53:SmallPowerBackToMeasuredValue..............................................................................116

3.56Case54:SmallPower@12W/m²........................................................................................................118

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3.57Case55:25%EnergyReductioninDataCenter..............................................................................119

3.58Case56:50%EnergyReductioninDataCenter..............................................................................121

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EXECUTIVESUMMARYItisdifficulttofindagoodcasestudyinMalaysiaaboutoptimizingenergyefficiencyinexistingbuilding.Therearemanyreasonsforthislackofgoodcasestudy,oneofwhichbeingthatmostbuildings in Malaysia are normally demolished and rebuilt rather than refurbished. The fewrecently retrofitted buildings inMalaysiawere refurbishedwithout consideration for energyefficiency,duelargelytothelackofpublicinformationonthepotentialofenergyefficiencyinexisting building. This represents a loss of opportunity to optimize the building energyefficiencyfortheseretrofittedbuilding.

This document was made to showcase the potential energy efficiency gain of retrofitting anexisting building fitted with technologies that are more than 20 years old with the currentenergyefficienttechnologyavailable today.Thestudywasbasedonacomputersimulationofanexistingbuildingwhereadetailedenergyauditwasconductedonthisbuildingin2008.Theenergy audit report provided sufficient data to enable the total energy consumption of thebuilding tobemodeledwithin0.1%accuracyof the totalbuildingenergyconsumption in thesimulationmodelascomparedtothemeasuredvalues.

Uponestablishingthisaccuratebasecasescenario,energyefficiencystrategieswereappliedontothesimulationmodelofthebuilding,testingeachstrategyforitsannualenergysavingsthatcanbeprovidedbyeachdesignfeature.

A total of 58 simulation cases were tested by this study. The combined maximum energyreductionpotentialofthesetested58caseswassimulatedtobe50.1%,providinganaverageof0.9%energyreductionperenergyefficiencyfeature.

KeyLessonsLearnedfromthisstudy

1. Itispossibletoreduceexistingbuildingenergyconsumptionbymorethan50%.2. Thereisnosingle“silverbullet”forenergyefficiencyinexistingbuildingwhereenergy

reduction can be brought down by 50% with just the implementation of one singledesignfeature.Minorimprovementmadeoneverypotentialenergyreductionfeaturesin the building provides the efficiency gain step by step until it reaches 50% energyreductionforthewholebuilding.

3. Airleakageinoldbuildingsisamajorsourceofenergyleakagesinbuilding.4. By implementation of energy efficiency features, the reduced capacity of the chiller

would itself, provides a significantbudget for the implementationof energyefficiencyfeatures.

5. Thisstudyalsoshowedthatitmaybepossibleforabuildingownertochangethechillertoalargercapacity,duetothecomplaintsreceivedfromthebuildingoccupantthattheexistingbuildingair‐conditioningsystemisnotprovidingenoughcoolingforthem.Thisextracostforalargerchillercouldbeusedinsteadforimprovementinenergyefficiencyfeatures of the buildingwhile keeping the capacity chiller the same as shown in thisstudyorperhapsevenreducethesizeoftheexistingchiller.

6. Reducing building cooling load has a “domino” effect in energy efficiency for thebuilding.Oncethebuildingcoolingloadisreduced,theair‐conditioningsupplyairflowrateandchilledwaterflowratecanbereducedaswell.Thereductionofairandwaterflowratereducesfan/pumppowerbyacubicfactorbecausetheyfollowthefan/pumpaffinity’slaw.Forexample,areductionof15%flowratereducesenergyconsumptionof

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thepumporfanbyalmost40%.Theheatgeneratedbythepumporfanwouldalsobereducedby40%,therebyfurtherreducingcoolingloadrequirementonthechiller.

7. Itmaynotbenecessarytoimplementvariablespeeddrive(VSD)foreveryequipmentinthe building. In this study for Block F, the cooling load was measured to be fairlyconstant and consistent every working day, the implementation of VSD on the AHU(converting it into a variable‐air‐volume system), and on the chilled water supply(primary/secondary) provided marginal efficiency gain. However, it should behighlighted too that if the building cooling load changes in future, the buildingwouldlack the ability to response efficientlywithout having VSD in the building.Moreover,VSDisnotanexpensiveitemandcanbeeasilyinstalledontoanexistingsystem.

8. It ismore energy efficient to oversize a cooling tower to provide as cold as possiblecondenser return water temperature to the chiller to gain chiller efficiencyimprovement than to seek fan energy reduction in cooling tower via the use of VSD.However,thismaybesystemspecific,i.e.dependingontheexistingchillerperformancecurve.FuturetechnicalguidelinefromBSEEPwilladdressthisissueinmoredetail.

9. It ismore energy efficient inBlockFbuilding to reduce flow rateof condenserwaterflow rate to 2.0 gpm/ton (instead of the typical flow rate of 3.0 gpm/ton) to save onpumping energy, while accepting a small decrease in chiller efficiency. However, thismayalsobesystemspecific,i.e.dependingontheexistingpumpefficiency,pumpheadandchillerperformancecurve..FuturetechnicalguidelinefromBSEEPwilladdressthisissueinmoredetail.

10. Heatrecoverywheelwouldonlyworkinanair‐tightbuilding.Theexhaustairducthastobecarefullydesignedtocaterfortheexpectedexhaustairflowrate.

11. Chiller efficiency has improved significantly over the past 20 years. This efficiencyimprovement(moneysaved)canpayfor½thecostofthenewchilleroverthelifetimeof15yearsforchillers.

12. Inavariable‐air‐volume(VAV)system,wheretheAHUfanpowerislow(asinBlockFafterthereductionofairflowrate),itwouldbemoreenergyefficienttosettheAHUtohave higher off coil temperature to reduce moisture removal (increasing relativehumidity, while ensuring that room relative humidity stayswithin the recommendedrange). Fan energy to delivery cooling to the room increases due to the lower airtemperaturedifferences,however, thesaving from lessmoistureremoval, savedmoreenergy for the chiller than the increase in fan power used. Future technical guidelinefromBSEEPwilladdressthisissueinmoredetail.

13. It is energy efficient to reduce general lighting level down to 200 lux level whileprovidingtasklightforthebuildingoccupants.Thepowerconsumptionofthetasklightitself(testedfrom19Wdownto5Wtasklight)hasaverysmallimpactonthebuildingenergyefficiency.

14. The energy efficiency gained from daylight harvesting is not significant in this studybecausethebuildingalreadyhasaverylowlightingpowerdensityandaveryefficientchilledwatersysteminplacebeforedaylightharvestingoptionwasconsidered inthisstudy. In a building where the mechanical and electrical equipment are not energyefficient,thebenefitfromdaylightharvestingwillbesignificantlyhigher.

15. Daylight harvesting in building has the potential to improve building occupantperformance, reduces sick leaves andgive anoverall better environment to the officespace.

16. Oncethebuildingair‐conditioningsystemhasbeenmadeveryenergyefficient,passivefeaturessuchashighperformancedoubleglazing,daylightharvestingusinglightshelve

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is shown to have poor financial feasibility. However, if these passive features wereimplemented before the air‐conditioning system is improved, its financial feasibilitywouldbemuchbetter.

TheimplementationofenergyefficiencystrategiesinJKR’sBlockFbuilding(~24,000m²)wassimulated to reduce the building energy consumption by RM 660,000/year or RM 2.30/m²/month.ThechillersizereductionduetotheenergyefficiencyfeaturesemployedontothebuildingprovidedanimmediatesavingofRM4.2million.ThesavingofRM4.2millioncanusedtofinanceamajorpart(ifnotall)oftheproposedenergyefficiencyretrofitforthisbuilding.

Asummaryofthe58simulationstepsemployedistabledbelowforquickreference.

Cases Short Descriptions BEI %Saved RM/year Saved

B0 Comfortable Base Case 172.7 ‐6.7% (88,481)

B1 Base Case As‐Is 161.9 0.0% ‐

C1 Air‐Tight the Building 156.1 3.5% 46,787

C2 Improve Comfort 164.3 ‐1.5% (20,036)

C3 Reduce Small Power at Night 160.7 0.7% 9,717

C4 Reduce Lighting Power 153.4 5.2% 69,401

C5 Office Use of Occupancy Sensor/Lighting Switches 148.7 8.1%

107,861

C6 Toilet Use of Occupancy Sensor 148.5 8.3% 109,566

C7 50% Lift shutdown after 7pm 147.8 8.7% 114,994

C8 Fresh Air Supply Regulated by CO2 sensor 141.5 12.6% 166,438

C9 Improve Comfort 144.8 10.5% 139,400

C10 Reduce Chill Water Flow Rate 142.8 11.8% 156,031

C11 Increase Chill Water Supply Temp to 9deg 141.5 12.6% 166,543

C12 High Delta Temperature Chill Water 140.3 13.3% 176,302

C13 Fix Duct Leakages 140.9 12.9% 171,230

C14 Increase AHU setpoint temperature 139.3 13.9% 184,654

C15 Reduce AHU flow rate 120.7 25.4% 336,747

C16 Use of low pressure loss air filters 118.2 27.0% 356,921

C17 Improve Fan Efficiency 117.6 27.3% 361,995

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C18 Use VAV system with off coil temp of 14 deg 117.5 27.4% 363,039

C19 Use VAV system with off coil temp of 16 deg 116.7 27.9% 369,343

C20 Lift Lobby Air Temp 27deg 116.3 28.2% 373,068

C21 Chiller Efficiency (COP of 6.3) 107.2 33.8% 447,149

C22 Use of VSD Chiller 104.3 35.6% 470,948

C23 Reduce Condenser Water Flow to 2.5 gpm/ton 102.2 36.8% 487,653

C24 Reduce Condenser Water Flow to 2.0 gpm/ton 101.5 37.3% 493,340

C25 Use of primary/secondary chill water system 101.6 37.2% 493,044

C26 Use of primary variable chill water system 101.4 37.3% 494,356

C27 Improve chill water pump efficiency 101.0 37.6% 497,921

C28 Improve condenser water pump efficiency 100.3 38.0% 503,378

C29 Improve all pump motor efficiency 100.1 38.1% 504,805

C30 Improve cooling tower fan efficiency 99.1 38.8% 513,573

C31 Cooling Tower VSD fan, setpoint 30.5 deg 99.4 38.6% 511,245





C36 Oversize cooling tower 98.6 39.1% 517,554

C37 Reduce Light Level to 200 lux, wt 19w Task Light 91.9 43.2%

572,190

C38 Reduce Light Level to 200 lux, wt 11w Task Light 91.2 43.6%

577,581

C39 Reduce Light Level to 200 lux, wt 5w Task Light 90.8 43.9% 581,589

C40 Daylight Sensor in Toilet 90.6 44.0% 582,760

C41 Use of Heat Recovery Wheel 88.1 45.6% 603,168

C42 Use of Clear Glazing 89.3 44.9% 593,841

C43 Daylight Harvesting in Offices, 3.5m depth 85.6 47.1% 624,004

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C44 Daylight Harvesting in Offices, 4.5m depth 84.6 47.7% 631,580

C45 Apply Performance Film on Clear Glazing 83.7 48.3% 639,522

C46 Use of Double Glazing High Performance 82.7 48.9% 647,467

C47 Roof insulation with 50mm polystyrene 82.4 49.1% 650,120



C50 Increase Air Temperature (comfort maintained) 81.1 49.9% 660,487

C51 Resize HVAC 80.7 50.1% 663,840

C52 Resize HVAC with 12 W/m2 small power 80.9 50.0% 662,187

C53 Small Power back to Base Case (no change) 84.6 47.8% 632,288

C54 Small Power up to 12 W/m2 117.2 27.6% 365,450

C55 Data Center reduces 25% energy 107.3 33.7% 446,177

C56 Data Center reduces 50% energy 97.4 39.8% 526,911

Itshouldbenotedthatthestrategiesandsavings listedintheabovetable isvalidforBlockFbuildingonly.ThedetailsofwhyeachofthisstrategyworkedforBlockFis fullydescribedindetail part of this document. Other existing building may have different problems and thesavingsfromeachstrategydescribedabovemaybedifferentforadifferentbuilding.

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1.INTRODUCTIONThistechnicalreportwasmadetoprovidetheresultofanenergyefficiencypotentialstudyonanexistingbuilding.TheBlockF,JKRHeadquartersbuildinginJalanSalahuddin,KualaLumpurwasselectedforthisstudy.Thisbuildinghasundergoneacomprehensiveenergyauditinyear2008byCofreth(M)SdnBhdandhasprovidedadequatemeasureddataforadetailedenergysimulationtobemodeledaccuratelyandcalibratedtothebuildingactualoperatingcondition.

Inthisstudy,theannualenergyconsumptionofthebasebuildingsimulationmodelwasabletobecalibratedintolessthan1%differencesfromtheEnergyAuditorreport,usingmatchingpeakpowerdataasprovidedintheEnergyAuditorreport.

58 simulation runs were conducted on this building with a total of 52 energy efficiencystrategiesandscenariostested.Thesummaryofresultisasshownviathefigure1and2below.Figure1,showedareductionofBuildingEnergyIndex(BEI)from172.7kWh/m²/yeardownto80.9kwh/m²/year,areductionof50.1%.

Figure1BEIReductionPotential

Figure2PotentialAccumulatedEnergyReductioninPercentagesfromMeasuredCaseScenario

Theresultofthisstudyshowedthatonlyfive(5)outof52energyefficiencyfeaturesproposedforthebuildingyieldmorethan4%savingswhenusedsingularly.Onaverage,eachproposed

0

20

40

60

80

100

120

140

160

180

200

B0

C1

C3

C5

C7

C9

C11

C13

C15

C17

C19

C21

C23

C25

C27

C29

C31

C33

C35

C37

C39

C41

C43

C45

C47

C49

C51

kWh/m

2/year

Block F Simulated BEI Potential

‐10%

0%

10%

20%

30%

40%

50%

60%

B0

C1

C3

C5

C7

C9

C11

C13

C15

C17

C19

C21

C23

C25

C27

C29

C31

C33

C35

C37

C39

C41

C43

C45

C47

C49

C51

% Accumulated Energy Reduction

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energyefficiency feature for thebuildingonly reducesapproximately1%.However,whenalltheproposed energy efficiency features areused in combination, thebuildingwasbe able tosave50%energyfromitsbasemeasuredcondition.

1.1BUILDINGENERGYSIMULATIONTheBlockF,JKRbuildingwasmodeledinenergysimulationsoftwarebasedonfoundhardcopyofbuildingplan,datedbackinthe1970s.

Figure3BuildingPlan

Figure4CrossSectionofBuilding

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Figure5EnergySimulationModel

Figure6PictureofBlockFatJalanSalahuddin

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Buildingenergysimulationisapowerfultool,allowingonetosimulateenergyperformanceforavarietyofscenarios.Itcansimulatetheperformanceofbuildingenergyconsumptionbasedon8760hoursofweatherdataofdrybulbtemperature,wetbulbtemperature,windspeed,winddirection, direct solar radiation, diffuse solar radiation and cloud cover. Building energysimulationcapturestheinteractiveeffectsofthemechanicalsystems,occupancyrequirementsandthebuildingenvelope.Thepurposeofrunningbuildingenergysimulationinthisstudyistotest the potential of energy efficiency of Block F, using various energy efficiency retrofitstrategiesthatareapplicableforthisbuilding.

Buildingsimulationisusedinthiscasetoevaluatetheenergyuseinexistingbuildingsasabasisfor understanding the current energy use and to predict energy reduction associated withbuildingretrofits.

The building energy simulation tool used for this study is the IES <Virtual Environment>version6.4.0.6fromUK(http://www.iesve.com).ItmeetstherequirementofAshraeStandard140 and Cibse AM11 for a building dynamic energy simulation tool. This software iscomprehensiveenoughtoallowallthetypesofpassiveandactiveenergyefficientstrategiestobestudiedforthepurposeofthisreport.

1.2WEATHERDATASubangTestReferenceYearThehourlyweatherdata ofKuala Lumpurused in the simulation studywasbasedon aTestReferenceYearweatherdatadevelopedbyGregersReimanninUniversityTeknologiMalaysia(UiTM)basedon21yearsofweatherdatafromtheMalaysianMeteorologicalStationinSubang,Klang Valley, Selangor in year 2000. The hourly weather data that were obtained from thisstationisasshowninTablebelow.

Table:WeatherdatacollectedinSubang

SubangMeteorologicalStation(KlangValley,Selangor,Malaysia)Longitude:101deg33'Latitude:3deg7'Parameters(hourly1) UnitsCloudcover [oktas]Drybulbtemperature [°C]Wetbulbtemperature [°C]Relativehumidity [%]Globalsolarradiation [100*MJ/m²]Sunshinehours [hours]Winddirection [deg.]Windspeed [m/s]

ATestReferenceyear(TRY)consistsofweatherdataforagivenlocation.InorderfortheTRYtoberepresentativeoftheclimateitwasconstructedonthebasisofatleast10yearsweatherdata.TheTRYismadeupfromactualmonthlydata(notaveragevalues)thatarepickedafterhavingbeensubjectedtothreedifferenttypesofanalysis.

1 The values are integrated over a period of one hour, but the exact time interval has not been specified.

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Itshouldbenotedthatenergysimulationprogramrequire2extradatathatwerenotcollectedby theMalaysianMeteorologicalService,namely thedirectanddiffuseradiation.ThemissingradiationdatawascalculatedfortheTRYviaErbs’EstimationModelfromthehorizontalglobalsolarradiationbyReimann.

Comparison of this set of weather data were made against the data provided by theInternational Weather for Energy Calculation (IWEC) and the weather data provided byMeteonorm. It was found that the TRY ismore accurate in predicting the direct and diffuseradiationsplitoftheKualaLumpurweatherdatabecauseitaccuratelypredictedthatthedirectradiationishigherinthemorningthanintheevening,onaveragethroughouttheyear,duetothe higher frequency of rainfall in the afternoon/evening hours in a tropical climate such asMalaysia.

Although not perfect, the TRY is currently themost accurate set of weather data for energysimulationavailabletodayforKualaLumpurandithasbeenusedinmanyenergysimulationsofvariousbuildingsinMalaysiawithsatisfactoryresults.Thisweatherdatawasalsousedforthedevelopment of the constants in the Overall Thermal Transmission Value (OTTV) equationfoundinthelatestMalaysiaStandard(MS)1525,EnergyEfficiencyinNon‐ResidentialBuilding.

1.3BASICINPUTDATASpacesTemplateDataforthebasebuildingscenarioOfficeSpace Air‐Conditioned:2AHUsystemsperfloor.

1AHUsharedwithOfficeSpace1and31AHUsharedwithOfficeSpace2andLiftLobby.Air‐ConditioningHours:ACHours FluorescentLighting MaxSensibleGain: 11.70W/m²MaxPowerConsumption: 11.70W/m²VariationProfile: OffLights People:OffPeople MaxSensibleGain: 90.00W/PMaxLatentGain: 60.00W/POccupantDensity: 20.00m²/person(1,000personforthewholebuilding)VariationProfile: 8‐6weekdayworking Computers:OffSmPwr MaxSensibleGain: 4.10W/m²MaxPowerConsumption :4.10W/m²VariationProfile: OfficeSmPwr InfiltrationVariationProfile: InfiltrationsMaxA/CRate: 1.65AC/h

LiftLobby Air‐Conditioned:SharedAHUwithOffice2

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FluorescentLighting: 5.50W/m²VariationProfile: LobbyLgtsInfiltration: 1.65AC/hVariationProfile: Infiltrations

Stairs Un‐ConditionedSpace. FluorescentLighting MaxSensibleGain: 4.00W/m²MaxPowerConsumption: 4.00W/m²VariationProfile: StairsLights InfiltrationType InfiltrationVariationProfile: oncontinuouslyMaxA/CRate: 1.50AC/h

Toilets Un‐ConditionedSpace. FluorescentLighting:MaxSensibleGain: 4.60W/m²MaxPowerConsumption: 4.60W/m²VariationProfile: ToiletLights InfiltrationVariationProfile: oncontinuouslyMaxA/CRate: 1.50AC/h

LiftPower MaxPowerConsumption :25kWfor6lift.VariationProfile:LiftPwr

FacadeLights MaxPowerConsumption:1984.00WVariationProfile:FacadeLgts

Data Center,inclusive ofPrecision Air‐ConditioningSystem

MaxPowerConsumption :105.325kWVariationProfile:oncontinuously

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1.4OPERATIONDAILYANDWEEKLYPROFILESOperationHourly,DailyandWeeklyProfiles

1. ACHours

2. OffLights

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3. 8‐6weekdayworking(PeopleOccupancy)

4. OfficeSmPwr

19

5. Infiltrations

20

6. LobbyLgts

7. StairsLights

21

8. ToiletLights

22

9. LiftPwr

23

10. FacadeLgts

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2.BASESIMULATIONMODELVSMEASUREDDATA

2.1ENERGYRESULTSCOMPARISONAlldatausedbythesimulationmodelwasderivedfromthemeasuredpeakpowerconsumptionwith the exception of chiller coefficient of performance (COP). The chiller COP has to becalibrated in the simulation study because the simulation softwarewas unable to simulate adifferentchillerCOPeveryalternatedayaspracticedbyBlockFbuilding.

Cut out of measured tables from Energy Auditor’s report is provided alongside with thesimulatedvalues.

Table1EnergyAuditorReportonAnnualEnergyConsumptionofBlockF

Simulated Results

Date Total energy (MWh)

Jan 01‐31 316.8979

Feb 01‐28 291.7742

Mar 01‐31 340.1605

Apr 01‐30 301.8921

May 01‐31 340.8951

Jun 01‐30 322.0787

Jul 01‐31 307.8406

Aug 01‐31 333.5537

Sep 01‐30 300.0826

Oct 01‐31 318.7742

Nov 01‐30 307.8691

Dec 01‐31 300.6721

Summed total 3782.491 Table2SimulatedBaseScenarioofAnnualEnergyConsumptionofBlockF

Thesimulatedtotalannualenergyconsumptionofthebuildingof3,782MWh/yearisonly2.2%lowerthanmeasuredvalueof3,866MWh/year.

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Figure7MeasuredDailyEnergyConsumption

Figure8SimulatedDailyEnergyConsumption

Thesimulationof theenergyconsumptionof theLowVoltage(LV)circuit,ChillerSystemandTotalmatchesfairlywellwiththemeasuredvalues.

The maximum demand of the chilled water production also matches closely between themeasuredvalue(447MW)andthesimulationvalue(469MW).

Table3MeasuredElectricityConsumptionforChilledWater

‐

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

Sat Sun Mon Tue Wed Thu Fri

Simulated Total Energy Consumption (kWh) on Weekly Basis

LV Chiller System Total

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Days Max Demand (kW)

Chiller system Daily (kWh)

Sat

468,746

‐

Sun ‐

Mon 4,293

Tue 4,595

Wed 4,781

Thu 4,488

Fri 4,621 Table4SimulatedElectricityConsumptionofChiller,BaseScenario(Week2)

Table5MeasuredChilledWaterSystemBreakdown

Days Chiller Daily (kWh) Cooling Tower & Condenser Pump

Chill Water Pump

Sat ‐ ‐ ‐

Sun ‐ ‐ ‐

Mon 3,023 727 542

Tue 3,338 728 529

Wed 3,466 750 565

Thu 3,284 713 491

Fri 3,368 726 526

Total 16,480 3,644 2,653 Table6SimulatedBaseScenarioofChilledWaterSystemBreakdown(Week2)

TheIESsoftwareusedforthissimulationlumptogetherthecoolingtowerandcondenserpumppowertogetherasheatrejectionpowerused. Inaddition, itwasalsonotpossible tosimulatealternate chiller COP used on the same or alternate days. Only one chiller ismodeled in thesimulationwhilethemeasuredresultcontainstwo(2)chillerswithtwodifferentCOP.

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Table7MeasuredAHUElectricityConsumption

Days Max Demand (kW) AHU Daily (kWh)

Sat

171.54

‐

Sun ‐

Mon 1,973

Tue 1,973

Wed 1,973

Thu 1,973

Fri 1,973

Total 9,864 Table8 SimulatedBase ScenarioAHUElectricityConsumption(Week2)

ThedailyAHUenergyconsumptioninthesimulationmodelwassimulatedtobelowerthanthemeasured value based on the average peak power measured at every AHU. It was laterdiscovered by JKR that the measured value of AHU circuit includes one precision air‐conditioningunitusedbythedatacenter.Whentheenergyconsumptionofthisprecisionair‐conditioning unit is removed from the measure value, the numbers matches between thesimulationandmeasuredvalues.

Table9MeasuredDailyLoadforLift


Lift Daily Load (kWh)

Sat

25.00

126

Sun 126

Mon 363

Tue 363

Wed 363

Thu 363

Fri 363

Total 1,941 Table10SimulatedBaseScenarioLiftDailyLoad

Thesimulatedweeklylift(verticaltransport)energyconsumptionmatchesthemeasuredvalueaccurately.

Table 11 Measured Energy Consumption forLightingandSmallPower


Lights and Small Power Daily (kWh)

Sat

338.76

758

Sun 758

Mon 3,737

Tue 3,737

Wed 3,737

Thu 3,737

Fri 3,737

Total 19,441

Table 12 Simulated Base Scenario, Lighting andSmallPower

Thelightingandsmallpowerenergyconsumptionwasalsomatchedwellthesimulationvalueof19,441kWhperweek,being6.3%lowerthanthemeasuredvalueof20,757kWhperweek.

28

Table13MeasuredLightingandSmallPower

Total Lighting + Small Power (kWh)

Total Lights (kWh)

Total Small Power (kWh)

Annual Load (kWh) 1,051,104 701,779 349,324

Percentages (%) 100% 67% 33% Table14SimulatedBaseScenario,LightingandSmallPower

Thedistributionoflightingandsmallpowerenergyconsumptionhastobesplitbytheenergyauditormanuallybecausetheyweresharingthesamemeasuredcircuitry.Theenergyauditorderivedtheenergysplitbetweenthesmallpowerenergytothelightingpowerenergyinaratioof2:1.Thisratiowasmaintainedinthesimulatedresultasshownintable14.

Table 15 Measured Measured Facade LightingElectricity


Façade Lighting Daily (kWh)

Sat

1.98

24

Sun 24

Mon 24

Tue 24

Wed 24

Thu 24

Fri 24

Total 143 Table 16 Simulated Base Case Facade LightingElectricityConsumption

Thesimulatedfaçadelightingenergyforatypicalweekis143kWhascomparedtomeasuredvalueof110kWhperweek foradifferenceof30%.Thesimulationwasbasedon theenergyaudit report of peak façade lighting load of 1.98 kW each night. However since the façadelighting contributes to a small fractionof thebuilding total energyuse, this figurehas a verysmallinfluenceinthewholebuildingscenario.

29

Table17MeasuredEnergyBreakdownbySystem

Descriptions Measured (kWh) Simulated (kWh)

% diff from Measured

Chilled Water Production System 1,188,724 1,188,216 0.0%

Air Handling Units (AHU) 603,640 512,909 ‐15.0%

Air Handling Units, without weekend and nights 517,090 512,909 ‐0.8%

Lighting and Small Power 1,085,851 1,051,104 ‐3.2%

Domestic Pump 14,783 ‐ ‐100.0%

Vertical Transport 101,587 107,610 5.9%

Others (Essential Supply) 871,804 922,647 5.8%

Total (using AHU without weekends and nights) 3,779,839 3,782,486 0.1% Table18SimulatedBaseCaseEnergyBreakdownbySystemcomparedtoMeasuredvalues

Thecomparisonbetweenthemeasuredandsimulatedannualenergyconsumptionyieldanetdifferenceof0.1%.Thechilledwaterproductionhasa0.0%differencesbecausethesimulationwascalibratedtomatchthemeasuredvalue.

Figure9TypicalWeekAHUPowerUsage

The simulationof the air‐handling‐units (AHU)energy consumptionwas15% lower than themeasured value. The simulation was based on the average measured peak AHU powerconsumptionas the inputbasis.Further investigationshowed that themeasuredAHUenergyconsumption includes a precision air‐conditioning unit used by the data center. The energy

20kW,approximately75%ofnon‐chillersoperatinghours

30

consumption by the precision air‐conditioning unit should not be part of the AHU energyconsumption. The precision air‐conditioning unit energy consumption should be lumpedtogetherwiththedatacenterenergyconsumption.

ItwasestimatedfromFigure9thattheprecisionair‐conditioningunitconsumesonaverage,20kW during operation and it is running every alternate few hours. A quick estimate from thefigure9showedthatthisprecisionair‐conditioningunit isrunningapproximately75%ofthehoursduringthetimetheAHUisnotrunning.

ChillerOperatingHours=7am to6:30pm (11½hours),Monday toFriday =11.5hours x5days/weekx52weeks=2990hoursperyear.

HoursAHUrunningwithoutchillerrunning=(8760–2990)x75%=4327.5hoursperyear.

PrecisionAirConditioningUnit,EnergyConsumptionEstimateduringweekendsandnighttime=4327.5hoursx20kW=86,550kWh/year.

Measured energy use by the AHU only = 603,640 (measured) ‐ 86,550 (estimate of precision air

conditioning unit) = 517,090 kWh/year.

Figure10SimulatedAHUPowerUsage

ThesimulatedAHUenergyis512,909 kWh/year or 0.8% lower than the measured value.

The lighting and small power simulated annual energy consumption is 3.2% lower thanmeasured value. The domestic pump was not modeled in the simulation case because theconsumptionisonlyafractionofthebuildingtotalenergyconsumption.Theverticaltransportannual energy consumptionwas simulated to be 5.9% higher than themeasured value. Theannualenergyconsumptionof“others(essential)”,i.e.thedatacenter,wassimulatedtobe5.8%higher than the measured value. The overall comparison of annual energy consumptionbetweenthemeasuredandsimulatedvalueshasadifferenceof0.1%onlyafteraccountingfortheprecisionair‐conditioningunitmeasuredattheAHUcircuitry.

Sat Sun Mon Tue Wed Thu Fri Sat

180

160

140

120

100

80

60

40

20

0

Pow

er (

kW)

Date: Sat 14/Jan to Fri 20/Jan

ApHVAC distr fans energy: (01base01_as_is.aps)

31

Table19MeasuredEnergyBreakdownforChilledWaterSystem

Descriptions Measured (kWh)

Simulated (kWh) % diff from Measured

AHU 603,640 512,909 ‐15.0%

AHU without weekends and nights 517,090 512,909 ‐0.8%

Chillers 858,977 863,176 0.5%

Heat Rejection (Cooling Tower & Condenser Pump) 179,445 189,792 5.8%

Chilled Water Pumps 141,475 135,248 ‐4.4%

Others 8,827 ‐ ‐100.0%

Total (using AHU without weekends and nights) 1,705,814 1,701,126 ‐0.3% Table20SimulatedBaseCaseEnergyBreakdownforChilledWaterSystemcomparedtomeasuredvalues

The chilledwater system breakdown comparison between the simulated andmeasured casealsoyieldssimilaraccuracyrange.Thesimulatedchillerannualenergyconsumption ishigherby0.5%becauseitwascalibratedtomatchascloselyaspossible.Thesimulatedheatrejectionannualenergyconsumptionishigherby5.8%,whilethechilledwaterpumpislowerby4.4%.The“Others”,i.e.switchboard&otherstandbylosses,wasmeasurablebutwasnotsimulated,againthisisasmallfractioncomparedtothewholebuildingenergyconsumption.

The building energy index (BEI) was computed by the energy audit report to be 158.81kWh/m²/year.ThisBEIwascalculatedbasedonthemeasuredair‐conditioningareaof24,345.4m². However, the simulation model created from the building plans yields a smaller air‐conditionedareaof23,367.86m²,or4%lowerthanthemeasuredarea.Sinceallthesimulationcasesrunarebasedonthesimulationmodel,thesimulationair‐conditionedareaof23,36.86m²isusedasthebasisforallcomputationmadeinthisdocument,includingtheBEI.

32

Descriptions Measured Simulation Model

% diff from Measured

Air Conditioned Area (m2) 24,345.40 23,367.86 ‐4.0%

3,782,490.723,367.86 ²

161.87

The area differences can be attributed to the different methodology used to measure thebuilding.Thesimulationcasemodeledthebuildingusingdrawingsfound,whileenergyauditorconductedsitemeasurementtoestimatethebuildingair‐conditionedarea.

Inthisstudy,thesimulationmodelair‐conditionedarea(m²)isusedconsistentlyintheentirereport.ThiswillcausethebasescenarioBuildingEnergyIndex(BEI)tohaveaslightdifferencesascomparedtotheenergyauditor’sreport.

33

2.2TEMPERATUREANDHUMIDITYCOMPARISONThemeasuredtemperatureandhumiditybyEnergyAuditorisasshowninthetablebelow.Itshowedanaverageairtemperatureinofficestobe24.6°Candamaximumtemperatureof27°Candminimumof23°Cduringair‐conditioninghours.

Table21MeasuredTemperatureandHumidity

However,feedbackfromthebuildingoccupantsinJKRindicatesthattheofficesabovethe8thflooraresignificantlywarmerthanofficesbelowthe8thfloor.Thesimulatedtemperatureandhumidityofofficespaceandlobbyisshowninthefiguresbelow.

Figure11TypicalDayAirTemperature

Figure12TypicalDayRelativeHumidity

The typical days air temperature in the offices during office hours was simulated to be justbelow26°C.Onahotday,itgoupashighas27°Candonacoldday,itreducesdownto24°C.The relative humiditywas simulated to bewell above 70% almost at all timewith amax of82~83%.Thesenumbersseemstomatchthemeasuredvaluesfairlywell.

00:00 06:00 12:00 18:00 00:00

29.529.028.528.027.527.026.526.025.525.024.5

Te

mp

era

ture

(°C

)

Date: Tue 14/Feb

Air temperature: OFFICE3_F07 (01base01_as_is.aps)

00:00 06:00 12:00 18:00 00:00

95

90

85

80

75

70

65

60

Pe

rce

nta

ge

(%

)

Date: Tue 14/Feb

Relative humidity: OFFICE3_F07 (01base01_as_is.aps)

34

Figure13HotDayAirTemperature

Figure14HotDayRelativeHumidity

Figure15CoolerDaysAirTemperature

Figure16CoolerDaysRelativeHumidity

Figure17TypicalDayLobbyAirTemperature

Figure18TypicalDayLobbyRelativeHumidity

00:00 06:00 12:00 18:00 00:00

29.529.028.528.027.527.026.526.025.525.024.5

Te

mp

era

ture

(°C

)

Date: Mon 22/May

Air temperature: OFFICE3_F07 (01base01_as_is.aps)

00:00 06:00 12:00 18:00 00:00

95

90

85

80

75

70

65

60

Pe

rce

nta

ge

(%

)

Date: Mon 22/May

Relative humidity: OFFICE3_F07 (01base01_as_is.aps)

00:00 06:00 12:00 18:00 00:00

28.528.027.527.026.526.025.525.024.524.023.5

Te

mp

era

ture

(°C

)

Date: Tue 14/Feb

Air temperature: Lobby_F06 (01base01_as_is.aps)

00:00 06:00 12:00 18:00 00:00

100

95

90

85

80

75

70

65

60

Pe

rce

nta

ge

(%

)

Date: Tue 14/Feb

Relative humidity: Lobby_F06 (01base01_as_is.aps)

00:00 06:00 12:00 18:00 00:00

28.528.027.527.026.526.025.525.024.524.023.5

Te

mp

era

ture

(°C

)

Date: Mon 22/May

Air temperature: Lobby_F06 (01base01_as_is.aps)

00:00 06:00 12:00 18:00 00:00

100

95

90

85

80

75

70

65

60

Pe

rce

nta

ge

(%

)

Date: Mon 22/May

Relative humidity: Lobby_F06 (01base01_as_is.aps)

35

2.3DATACENTERINBLOCKFThedatacenteronthe16thfloorofBlockFservestheentireJKR’sworkforcefromBlockAtoF,in Jalan Sultan Salahuddin. It has an average power consumption of 105 kW over 24 hours,everydayoftheyear.ThisisshownbytheFigure19&20below,labeledasOthers.Thepowerconsumption of this data center includes all the servers and the precision air‐conditioningsystem.(Itwaslaterfoundthatoneoftheprecisionair‐conditioningunitswasnotconnectedtothiscircuitrybecauseitwasconnectedtotheAHUcircuitryinstead).

Thedatacenterpowerwasnotreducedinthisstudyuntilthelast2casesinthisstudy,i.e.case55and56.ThepredictedpeakenergysavinginBlockFof50.1%didnothaveanyreductiononthedatacenterenergyconsumptionatall,althoughthedatacenterenergyconsumptionisusedintheBEIcomputationinallcases.ThisisshowninFigure21&22.

Figure19PowerUsageProfileinBlockF

Figure20EnegyConsumptionofBlockF

36

Figure21SimulatedBaseCaseEnergyConsumptioninBlockF

Figure22Case51EnergyEfficientScenario‐DataCenterremainsthesameasBaseCase

‐

200,000

400,000

600,000

800,000

1,000,000

1,200,000

1,400,000

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

Chilled

Water

Production System

Air Handling Units

Lighting and Small

Power

Domestic Pump

Vertical Transport

Others (Essen

tial

Supply)

Simulated Base Case Energy Consumption of Different Systems

Simulated (kWh) %

‐ 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000

0%5%

10%15%20%25%30%35%

Chilled

Water

Production

System

Air Handling Units

Lighting and Small

Power

Domestic Pump

Vertical Transport

Others (Essen

tial

Supply)

Case 51 Energy Consumption of Different Systems

Simulated (kWh) %

37

3.ENERGYEFFICIENCYRETROFITSPOTENTIALFORBLOCKFBytheimplementationof52proposedenergyefficientdesignfeaturesinBlockF,thebuildingenergyindexdropsfromahighofapproximately170kWh/m²/yeardowntoapproximately80kWh/m²/year.Insimulationcase54,thesmallpoweruseisincreasedto12W/m²toreflectatypicalsmallpowerenergyusedinofficebuildingsinsteadofthemeasuredsmallpowerpeakuseof4.1W/m²asdocumentedbytheEnergyAuditor’sreport.ThiswouldthenincreasestheBEIof thebuilding slightly to120kWh/m²/year.Energy efficiency in thedata center is thenrequiredtopushthebuildingBEIbelow100kWh/m²/year.

ELECTRICITYTARIFFAnelectricitytariffrateof0.35RM/kWhisusedinthisdocumenttocomputealleconomicdata.

0

20

40

60

80

100

120

140

160

180

200

B0

C1

C3

C5

C7

C9

C11

C13

C15

C17

C19

C21

C23

C25

C27

C29

C31

C33

C35

C37

C39

C41

C43

C45

C47

C49

C51

C53

C55

kWh/m

2/year

Block F Simulated BEI Potential

38

3.1BASECASE0:THECOMFORTABLEBASECASESCENARIOGeneralDescriptions

Theas‐isbasecasescenario(BaseCase1)hasanaverageairtemperatureof25°Candanaveragerelativehumidityabove70%.Thisisconsistentwiththemeasureddata provided by Energy Auditor’s report. From the as‐is base case 1 scenariosimulation, it was found that the chiller capacitywas inadequate to cater for theexistingbuildingcoolingload.

In thissimulationcase,basecase0, thechillercapacitywas increased tocater fortheactualcoolingloadrequirement.

DesignDetails

BaseCase0 ChillerCapacity Required:3500kWcooling(995 Ton)

As‐Is Base Case 1, Chiller Capacity: 1330 kW cooling (380 Ton), this capacity isbelowthebuildingrequirementandisreflectedbytheuncomfortabletemperatureinofficesasmeasuredandsimulatedbyBaseCase1.

BUILDINGBEI(kWh/m²/year) 172.7

EnergySavedkWh/year/m²(%)

‐6.7%

EnergySaved(kWh/year) ‐253,000

RinggitSaved(RM/year) ‐88,500

ProposedLifeTime NA

Budget Available forInvestment(RM)

NA

Remarks:Thisscenariowasmadetocomputethepeakchiller loadrequiredtokeeptheentirebuildingcomfortable. A very likely scenario, if energy efficiency is not addressed in this building, thebuildingownerwouldhavetoorderachillerof995Toncapacitytoaddressthecomfortissuefacedbytheoccupantsofthisbuilding.The computed peak cooling load of 3,500 kW (995 Ton) for this building scenario representapproximately a cooling loadof150W/m² (47Btu/hrper ft²)of air‐conditioned space. Theexistingchillercapacityof1330kWisequivalentto57W/m²(18Btu/hrperft²).Itislikelythatthis chiller capacity was selected during the days (early 1990s) when small power load inbuildingwaslowwithveryfewusersofpersonalcomputerinthebuilding.

39

3.2BASECASE0:AS‐ISBASECASESCENARIOGeneralDescriptions

The as‐is base case scenario (Base Case 0) has been simulated using the data ofmeasuredvaluesfromEnergyAuditor’sreport.

All inputdata for the simulationcase is exactly aspermeasurementvalueon sitewiththeexceptionofthechillercoefficientofperformance(COP)orkW/ton,whichwascalibrated.

Forthebasecasesimulationstudy,theCOPofthechillerwascalibratedtogivethecorrectannualenergyconsumptionofthechiller.

Details TheEnergyAuditor’sreportmentionedthattherewere3differentchillersinBlockF,which isusedoneatatime,everyalternateday,duetotheconfigurationof thechill water pipe circuit. Chiller #1 was out of order during the period ofmeasurement conducted by the energy auditor. The kW/ton of the 2 measuredchillersare:

Where,0.81kW/ton=4.34COP0.72kW/ton=4.88COP

It was not possible to run simulation based on 2 different chillers COP everyalternateday.ItwasthendecidedtocalibratethechillerCOPofthesimulationcasetomatchwith theactualmeasuredannualenergyconsumptionofboth thechillerforthebuilding.

CalibratedCOPofthesinglestagescrewchillerforthebasecaseyieldedavalueof4.88(0.72kw/ton)tomatchthesimulatedannualchillerenergyconsumptiontothemeasuredannualchillerenergyconsumptionwithinasmallerrormargin0.5%.



NA

EnergySaved(kWh/year) NA

RinggitSaved(RM/year) NA

ProposedLifeTime NA


NA

Remarks:The calibrated single stage screw chiller COP of 4.88 provided an annual chiller energyconsumption of 863,176 kWh/year. This value matched with the measured chiller energyconsumptionof858,977kWh/yearwithadifferenceof0.5%only.

40

3.3CASE1:FIXAIR‐TIGHTNESSOFBLOCKFGeneralDescriptions

In a separate reportmade by CawanganAlam Sekitar dan Tenaga (CAST), JKR in2010,themeasuredvalueoftotalfreshairintakeforBlockFwasfoundtobeaveryhighvalueof1.65air‐changesperhour(ach).Thisincludesboththefreshairintakeandinfiltrationofoutdoorairintobuilding.

Themeasuredhigh intake of fresh air is causedby the partially openedwindowsanddoorsatthattimeasshowninthesepicturesbelow.

Details Thebase casehas a combinedmechanical supply fresh air and infiltration rate of1.65ach.

Thissimulationcasestudyassumedthatall theseair leakagesare fixed.The freshairintakefromtheAHUroomismaintainedat10%flowrateofthesupplyair.Thebuildingisassumedtoex‐filtrateallthefreshairsuppliedfromtheAHUroom.

For the simulation in this case, it is assumed that the same air‐temperature ismaintainedfortheofficesroomasperthebasecasescenariotocomputetheenergysavingpotentialby reducing infiltrationof freshair intobuilding. However, sincethebuildingwasnotcomfortable inthe1stplace, it is likelythatanyimprovementmade to the building will be targeted towards providing comfort rather thanprovidingenergysaving.



3.5%

EnergySaved(kWh/year) 134,000

RinggitSaved(RM/year) 46,800

ProposedLifeTime 10


RM468,000forwholebuildingorRM190perm²glazing

Remarks:Improvingthebuildingair‐tightnesswhilemaintainingthesamecomfortconditionasthebasecasewouldprovideasignificantbuildingenergyreductionof3.5%.However,duetothereasonthatexistingcondition isnot comfortable for theoccupant in thisbuilding, it isexpected thatuponimprovementmadetothebuildingair‐tightness,comfortconditionwillbeprovidedtothebuildingviathereductionofairtemperaturefortheoffices.

41

3.4CASE2:BETTERCOMFORTGeneralDescriptions

Duetothereasonthatthechillerinstalledforthebuildingisinadequatetoprovidethe necessary cooling to the entire building, the average air temperature wassimulatedtobe25°C.

However, once thebuilding air‐tightnesshas been improved, the chillerwouldbeable toprovide themore coolingnecessary for the average air temperature tobereducedfromtheaverageof25°C.

Details Thebasecasesimulationstudytakesintoaccountoftheairleakagesintheduct.ThemeasuredtemperatureintheAHUroomisapproximately1°Clowerthantheofficeroom temperature. It has been calibrated in Case 9 simulation (when the chillercapacityisadequatetoprovidethenecessarycoolingtothebuilding)toallowaby‐pass(leakages)of20%ofsupplyair intothereturnairstreamtoachievethis1°Clowerthantheofficeroomtemperature.

Theair‐temperaturesetpointwastobesetto20°CintheAHUroom.However,thesimulation showed that itwasonlypossible for theoffices tohave an average airtemperature of 23.8°C. In this simulation study, the chiller capacity was stillinadequate tokeeptheroombelow23.5°C.Theaverageair temperatureof23.8°Cwas maintained until Case 9, where the cooling load of the building has beenbroughtdownlowenoughfortheexistingchillercapacitytoprovidethenecessarycoolingtomaintain23.5°C.



‐5%



ProposedLifeTime NA


NA

Remarks:Improvementtothebuildingair‐tightnesswouldallowthebuildingtohaveamorecomfortable(colder)airtemperature.Theimprovementincomfortcausesthelossofallthegainmadefromimprovingthebuildingair‐tightness.

42

3.5CASE3:SMALLPOWERREDUCTIONATNIGHTGeneralDescriptions

SmallpoweruseinblockFbuildingduringnighttimeandweekendwasmeasuredtobeapproximately25%ofthepeakdaytimeload.

These are small power use due to standby power consumption of computers,monitors,printers,refrigeratorsandanyotherelectricalequipmentthatispluggedtothepowerpoint.Evenaphonechargerthatisleftonthepowerpoint(nophoneconnected)wouldhave2~5wattstandbypowerconsumptionif theswitchonthepowerpointremainswitchedon.Alltheseequipmentstandbypowerconsumptionanda fewofficeequipment thatwerenotswitchedoff, lead to themeasured25%baseloadduringnighttimeandovertheweekendofsmallpowerconsumption.

Details The measured lighting and small power consumption of block F is as shown inFigure23belowforatypicalweek.Thesmallpowerconsumptionisthencomputedbydeductingthelightingpowerconsumptionfromthisgraph.Atableoflightingperwing,perfloorwasprovidedbytheenergyauditreport(asamplecutoutisshowninTable22).Thebaselightingpowerconsumptionovertheweekendandnightwascomputedbyassumingthatalllightinthestaircasesandexitsignsareswitchedonatalltimeand20%ofliftlobbylights,2%ofofficelightsand10%oftoiletlightsarestillswitchedonduringnighttimeandovertheweekend.

Figure23MeasuredTypicalWeekofLightingandSmallPowerConsumption

Level Room No./Description

No. of lamps/ fitting

No. of fittings

Total No. of lamps

Watts (lamp + ballast)

Total Watts

No. of Faulty Lamps

Total Watt for Faulty Lamps

Actual Lighting Power (W)

17 Staircase L 2 2 4 20 80 0 0 80

17 Office R 3 4 12 40 480 0 0 480

17 Office (Director) 3 1 3 20 60 0 0 60

17 Office (Director) 3 1 3 40 120 0 0 120

17 Meeting Room 3 6 18 40 720 0 0 720

17 Meeting Room 1 12 12 26 312 0 0 312

17 Meeting Room 1 8 8 20 160 2 40 120

17 Meeting Room 1 8 8 18 144 1 18 126

17 Eng Accreditation

3 3 9 20 180 0 0 180

Table22SampleCutoutofAppendix4.4.2fromEnergyAuditorReportofLightingPower

43

Itisassumedinthissimulationthatthis25%ofthepeakdaytimeloadatnightcanbereducedto10%withtheuseof timerstoswitchoffequipmentthataresharedandisnotrequiredtorunatnight.Thepotentialitemsthatcanbeswitchedtotallyoffduringnon‐occupiedhoursarepersonalcomputers,printers,waterdispensers,microwaveovens,andetc.

Powermanagementinpersonalcomputerswouldhelptocontributestothissavingby ensuring that computers that are accidentally left on at night wouldautomaticallyhibernateorshutdownafteraperiodofnoactivityonit.



2.2%



ProposedLifeTime 3

BudgetAvailableforInvestment(RM)

40timersperfloorallocated.RM130/timer

Remarks:Toreducethesmallpowerbaseloadof25%to10%requiresthebuildingoccupantcooperationtoshutdownanyelectricalequipmentisnotbeingusedatthepowerpointitself.Thismayormaynotrequire theuseofweeklyprogrammableautomatic timer.Anallocationof40 timersper floorwasassumed tobeused toshutdownnon‐criticalelectricalequipmentduringnon‐occupancy hours to compute the available budget for investment of these timer. Equipmentsuch as hot/cold water dispenser and shared printers/photocopiers can be shut down after7pmatnightandbeswitchedbackonagainat7amfortheseofficesduringweekdaysandbetotallyoffduringtheweekend.Itisalsorecommendedtoprovideextensionpowerpointplugtoextendthepowerpointtobelaidontopoftheworkingtableinsteadofonlyhavingthepowerpointonthefloorwhereitisinconvenientforbuildingoccupanttoreachforittoswitchitoffwhentheyareleavingtheofficeattheendoftheworkingday.Makingitconvenientforthebuildingoccupanttoswitchoffthepowersupplyatthepowerpointwillcutthestandbypowerconsumptiontotally.Partofthe25%basepowerconsumptionisduetotheuseofUPS(uninterruptedpowersupply)foreverycomputerinthebuildingbackinyear2008.TheUPSisrequiredtobechargedatalltimeandthereforeconsumingenergy24hoursdaily.FrequentchargeanddischargeofUPSwillshortenUPS lifespan.However,power failure inofficebuilding inKualaLumpur isquite rarethese days. In addition, almost all commonly used software such as Words, Excel andPowerPointhaveAutoSavefeatureinitthatifthereisapowerfailureonlyamaximum10‐15minutes of work is lost. It is also possible to change the AutoSave feature to a shorter timeperiod to prevent lesswork lost in case of power failure. A typicalUPS for a single personalcomputer consume up to 15 watt each. In a building like Block F, for 1,000 occupants, thisrepresents15kWofpowerconsumption24hoursdailyorRM46,000peryear.

44

3.6CASE4:OFFICEELECTRICALLIGHTINGEFFICIENCYGeneralDescriptions

There are a few options for energy efficiency in electrical lighting for an existingbuilding.Twooftheseoptionsaredescribedbelow.

Option 1: Replace existing T8 lamps (magnetic ballast) with T5 lamps with aconvertor and built in electronic ballast. This option does not require the lightfittingstobechangedandwouldreducetheenergyconsumptionthelampsfrom40wattsto30wattseach(includingballastlost).Thisprovidesa25%powerreductionimmediately.Thisoptionwouldallowtheofficeelectricallightingpowerdensitytobereducedfrommeasuredvalueof11.7W/m²downto9W/m²(25%reduction).

Option 2: Replace the entire light fittings with newer better light distributionfittings.ThenewlightfittingswithT5lampsandelectronicballastwouldallowtheofficeelectrical lightingpowerdensitytobereducedfrom11.7W/m²downto7.5W/m²orevenlower.

Details This simulation case study reduces the electrical lighting power consumption inofficesfrom11.7W/m²downto9W/m².



4.5%



ProposedLifeTime 3


RM30perlamps5925lampsrequiredforwholebuilding

Remarks:ThetypicalcostofT5lampswithconvertor(withbuilt‐inelectronicballast)intoT8lightfittingsis also approximately RM 30 per lamp. The lifespan of the T5 (or even T8) lamps isapproximately3~4years fora typicalofficebuilding.Therefore, itmayseemthat ithasanetzeronetpresentvalueadvantageovera3yearsanalysisperiod.However,theelectronicballastthatcomeswiththeseT5lampshasatypicallifespanof6~8years,allowingasecondchangeoftheT5lampsatthecostofthelampcostonly,whichiscurrentlyaroundRM10~15each.ItisalsoexpectedthatthecostofT5lampwillbereducesoverthenextfewyearsduetothehigherdemandandproductionofT5lamps.Therefore,thereisapositivenetpresentvaluewhenthisfeatureisevaluatedoveralongertimeperiod.

45

3.7CASE5:LIGHTSWITCHESAND/OROCCUPANCYSENSORINOFFICESPACEGeneralDescriptions

As in most offices, higher ranked staffs in Block F are allocated with their ownpersonal room. A typical walk about in Block F would shows that higher rankedstaffsholdmoreresponsibilitiesandarenormallybusyattendingmeetingsoutsidetheirownroom.Mostofthemwouldonlybeintheirownroomapproximately50%ofthetime.

Thiscasestudyassumesthatingeneral20%ofbuildingoccupantsarenotintheirplace due to reasons such as attending meeting outside the building, attendingmeeting inadenselypopulatedmeetingroom,onholidaysorhavingsick leaveofabsent. Theprovision of light switchesor occupancy sensor allows their personalroomlightstobeswitchedoffwhentheyarenotintheroom.

MeasuredlightingprofilefromtheLowEnergyOffice(LEO)ofMinistryofEnergyinparcel E4/5 in Putrajaya indicates that more than 50% of the lights can remainswitchedoffduringpeakworkinghoursduetothereasonabove.

In theLEObuilding,occupancy sensorwasplaced inevery room,however, itwasalso noted that building occupant do switch off the lights on their own as theywalked out of their own personal offices as long as the location of the switch isstrategicallyplacedsuchthatthebuildingoccupantisnotrequiredtotakeanyextrastepstoswitchoffthelightsastheywalkoutoftheroom.Thelightingswitchesarelocatedatlocationwhereifthelefthandisusedopenthedoor,thelightingswitchisplacedontherighthandforthebuildingoccupanttoturnitoffeasilyandvice‐versawhentherighthandisusedtoopenthedoor.

Unfortunately, due to the occupancy sensors provided in the LEO building, itremains uncertain if placing the lighting switches strategically is enough toguaranteeenergysavingwithouttheuseofoccupancysensor.

Details Thissimulationcasestudyassumesthattheelectrical lightingpowerconsumptioninofficesreducesby20%from9W/m²downto7.2W/m².



2.9%



ProposedLifeTime 5


RM570perOccupancySensorAllocated20sensorsperfloor.

Remarks:Thereexistofficespacestodaywhereone(1)lightingswitchisprovidedfortheentirespaceofmore than200m²housing up to 20 building occupants ormore. There are also office spacestodaywhere all the lighting switches are allocated together near themain exit door. Thesekindsoflightingswitcharrangementdonotallowanyenergyefficiencytobepracticedwhenasectoroftheofficespaceisempty.

46

For cost efficiency and reduced maintenance issue, it is recommended to use strategicallylocated lighting switches that allows for personal control of the lighting need. This type ofsolutionwouldneed thebuildingoccupants tohaveawarenessof energyefficiency toensurethattheywillswitchoffthelightswhenitisnotnecessarytobeused.However forgeneral openoffice spaceswhere there isnodistinctperson responsible for thelighting,occupancysensorisrecommendedtoensurethatthelightsareswitchedoffwhennooneisusingthespace.

47

3.8CASE6:OCCUPANCYSENSORINTOILETSGeneralDescriptions

Public space such as toilet is a location where lighting switches will not workbecausenooneisreallyresponsiblefortoiletlights.Thistypeofspacerequirestheuseofoccupancysensors.

There exists occupancy sensors that can sense occupants behind light weightpartitionssuchaswoodendoors/partitionthatarenormallyfoundintoilets.

Thesemotionssensorscanbeusedtoswitchoffthelightswhenitsensesthatthereisnooneinthetoiletanymore.

Details Thissimulationcaseassumesthat50%oftheworkinghoursthelightsintoiletsareswitchedoff.



0.1%



ProposedLifeTime 8


RM400/toilet

Remarks:Thissimulationisaguesstimateofthepercentageoftimethetoiletsareusedinofficebuildingduring office hours. By allowing the lights to be switched off 50% of the time, the budgetavailableforinvestinginthemotionsensorfortoiletsisRM400pertoiletinBlockF.

48

3.9CASE7:LIFTEFFICIENCYGeneralDescriptions

Itwasfoundthattheliftleftonstandbyallthetime,evenduringnon‐workinghours.The standby lift power during non‐occupancy hours was measured to beapproximately5kWonaverage.

Figure24MeasuredLiftPowerover1week

All the lift cannot be shut down totally because there are building occupants thatworkeduptolatenightsandwillrequirethelifttobeoperational.

However,itwouldbepossibletoshutdown50%ofthelifttobetotally,leavingonly3outof6liftstobeoperatingduringnon‐officehours.

Details Thissimulationcaseassumesthatliftpowerconsumptionreducedfrom5kWto2.5kWduringnon‐occupiedhours.



0.4%



ProposedLifeTime 8


RM7,240perlift

Remarks:The measured power consumption of the 6 number of lifts in Block F showed thatapproximately5to8kWisbeingconsumedeveninthehoursof12midnightto6am.Areductionof2.5kWduringnon‐occupiedhourswouldprovideasavingofRM5,400peryearforBlockF.

-20

0

20

40

60

80

kW

Time

Chart J : Load Distribution for Vertical Transport(For a typical workweek start from Saturday to Friday - 7

days)

49

3.10CASE8:CO2SENSORWITHMOTORISEDFRESHAIRDAMPERGeneralDescriptions

CO2 sensor withmotorized fresh air damperwill control the amount of fresh airintake into buildings by measuring the CO2 level from the return air. The morepeopleareintheoffices,thehighertheCO2amountandthemorefreshairwouldbeprovidedtotheofficestomaintainairqualityautomatically.

Thelesspeopleisintheoffices,thelessCO2amountisdetectedandlessfreshairisrequired to be supplied to the office and still provides a conditions of good airquality.Byreducingtheamountoffreshairprovided,thebuildingwillsaveenergybecausetheenergyforcoolinganddryingoffreshairisasignificantpartofthetotalenergyconsumptioninbuilding.

Details ThelimitofCO2issetto1,000ppm(partspermillion).



3.9%



ProposedLifeTime 8


RM12,100perAHU

Remarks:TheCO2controloffreshairrequirestwo(2)componentstobeinstalledineachAHUroom.

1. ACO2sensortodetecttheCO2levelofthereturnair.2. Motorisedfreshairdamperthatopenorclosethefreshairintakebasedonthereading

bytheCO2sensor.

50

3.11CASE9:BETTERCOMFORTAGAIN,REDUCEROOMTEMPERATUREGeneralDescriptions

Making improvement to the building allows the room temperature to be reducedfurtherforbettercomfort.

Details Itisnowpossibletomaintaintheofficesairtemperatureat23.5°Cwiththeexistingchiller capacity. Temperature set point in the AHU has to be adjusted to 22.5°C,whileroomtemperatureismaintainedat23.5°C.Thisdifferenceintemperatureiscaused by leakages in the supply air duct. Calibrated simulation showed that itrequires 20% of the air flow rate to be leaked back into the AHU to be able tomaintainatemperaturedifferenceof1°CinBlockF.



‐2.0%



ProposedLifeTime NA


NA

Remarks:ImprovingthecomfortofBlockFbuildingcostRM27,000peryearor2%ofthebuildingenergyconsumption. This large expenditure is partially caused by inefficient chilled water systemcurrently inplace.Once theair‐conditioning systemefficiencies is improved (asdone in latercases),theimpactofreducingairtemperatureinBlockFwouldbelesssignificant.

51

3.12CASE10:REDUCECHILLEDWATERFLOWRATEGeneralDescriptions

Theexistingchilledwaterflowratewasmeasuredtobe24%higherthanthechillerspecification.Thishighflowratehascausedthesupplychilledwatertemperaturetobe supplied at 10.4°C (50.7°F) instead of the set point of 6.7°C (44°F) mostlybecausethechillwaterdoesnotstaylongenoughforittobechilleddownto6.7°C.

Itispossibletoreducetheflowratebyinstallingavariablespeeddrive(VSD)orbychangingthemotoror/andpumptomatchthecorrectflowrateandpumpheadofthesystem.

Details In thissimulationstudy, chilledwater flowratewasreduced to thespecified flowrateforthe380tonchillerwithachilledwaterflowtemperaturedifferenceof5.6°C(10°F).

Thechilledwatersupplytemperaturewasalsoreducedto6.7°C(44°F)from10.4°C(50.7°F)previously,alongwiththereductionofchilledwaterflowrate.Thepumpaffinitylawisusedtocomputethenewpumpheadatthenewflowrate.

Duetothereducedchillwatersupplytemperature,theCOPofchillerwassimulatedtobereducedfromthepreviousaverageCOPof5.04downtoanaverageof4.4inthiscasescenario.



1.3%



ProposedLifeTime 8


Existing:2setsofchillwaterpumpRM66,520perpump

Remarks:Inthissimulationstudy,theexistingscrewchillerisappliedwitharatedCOPof4.88,however,theaveragerunningCOPofthechilleris5.04duetothehighsupplychilledwatertemperatureof10.4°C.Reducing thesupplychilledwater temperaturedownto6.7°C, theaveragerunningCOPofthechillerreducesdownto4.4from5.04earlier.Reducing the chill water flow rate also reduces the pumping energy significantly due thepump/fanaffinity’slaw.Thepump/fanaffinitylawsaysthat,Withimpellerdiameter(D)heldconstant:Law1a.Flowisproportionaltoshaftspeed:

Law1b.PressureorHeadisproportionaltothesquareofshaftspeed:

52

Law1c.Powerisproportionaltothecubeofshaftspeed:

where

Q is the volumetric flow rate (e.g. CFM, GPM or L/s),

D is the impeller diameter (e.g. in or mm),

N is the shaft rotational speed (e.g. rpm),

H is the pressure or head developed by the fan/pump (e.g. ft or m), and

P is the shaft power (e.g. W).

Fromthislaw,itwaspossibletocalculatethepumpheadandpumppowerreductionduetothereductionofchilledwaterflowrate.

53

3.13CASE11:INCREASECHILLEDWATERSUPPLYTEMPERATURETO9°CGeneralDescriptions

Chiller efficiency improveswhen the temperature differences between the returncondensertemperatureandthesupplychillwatertemperatureisreduced.Thiscanbedonebyreducingthecondenserreturnwatertemperatureorbyincreasingthechillwatersupplytemperature.

Details Inthiscasethechilledwatertemperatureisincreasedfrom6.7°Cto9°Ctoimprovethe efficiency of the chiller, since the chillerwas previously supply chill water at10.5°C.

COPofchillerimproved6.4%from4.40to4.68.



0.8%



ProposedLifeTime 8


2chillersRM42,000perchiller

Remarks:This feature is free because it is available as chillwater supply temperature set point in anychiller.Increasingthechillwatertemperatureimprovesthebuildingenergyefficiencyby0.8%.Thisstudyshowedthatinaconstantflowchillwatersystem,itmaybeagoodideatotesttheefficiency improvementof thesystemby increasing thechillwatersupply temperature. If theAHUwereoversizedbytheinitialdesign,thecoolingcoilwillnothaveanyproblemtoprovidethecoolingtothebuildingevenwiththeincreasedchillwatersupplytemperature.In the case of Block F, the energy efficiencymeasures taken up this stage have reduced thebuildingcoolingload(lowerlightingload,lowerinfiltration,lowersmallpowerload,etc.etc.),andtherefore,theexistingAHUwouldbeoversizedandwouldallowforthisoptimizationtobeaccomplished.

54

3.14CASE12:HIGHΔTCHILLEDWATERSYSTEMGeneralDescriptions

HighΔT(hightemperaturedifferences)chillwaterdesignreducespumppowerbyreducingtheflowrateofthechillwatersupplied.However,itrequiresthattheAHUcooling coil to be sized adequately to provide a higher leaving chill watertemperaturefromthecoolingcoils.

Details Theheatcapacityofflowingwaterisgovernedbytheequationshownbelow.

∆ Where;Q=Coolingload(kW)m=Massflowrateofwater(kg/s)Cp=Specificheatcapacityofwater4.187kJ/kg°C‐approx.4.2kJ/kg°C.ΔT=Thetemperaturedifferencebetweenflowandreturnwater.(°C)TheequationaboveshowedthatbyincreasingtheΔT,themassflowrateofwatercanbereducedtoprovidethesamecoolingcapacity.

For this simulation case, the chilledwater supply temperaturewas reduced from9°Cto6.7°C(44°F). Thereturnchillwatertemperaturewassimulatedtobe14°C(57°F) base on the existing cooling coil configuration based on the conditionsdescribedbelow.

Theexistingcoolingcoilconfigurationwasnotprovidedbytheenergyauditreport.The cooling coil configuration was derived from the assumed initial designparameter. The following assumptionsweremade to size the cooling coil for thisstudy:

Descriptions Values AssumedorFoundinEnergyAuditor’sReport

AirFlowRate 12,155cfmratedcapacity FoundinReportAirOncoilTemperature

23°C@50%RH Assumedbasedontypicaldesign.

AirOffcoilTemperature

12°C Assumedbasedontypicaldesign.

Wateroncoil 7°C(44.6°F) Assumedbasedontypicaldesign.Wateroffcoil 12°C(53.6°F) Assumedbasedontypicaldesign.

From the numbers above, it was possible to estimate the original cooling coilconfiguration and then predict the behavior of the cooling coil based on newconditionsastestedbythiscasescenarioofahighΔTchillwaterflowrate.

BasedonthenewconditionofhighΔTdesign,itcanbecomputedthattheexistingcooling coil configurationwould reduce the chillwater flow rateby50%, and thewateroffcoiltemperatureatthisconditionwouldbe14°C.

The average COP of chiller reduces from 4.68 down to 4.4, due to the lowertemperatureofthesupplychillwaterinthiscase.

55



0.7%



ProposedLifeTime 8


RM39,000/pumpThisfeatureisfreeforblockF.Refertoremarksbelow.

Remarks:HighDelta‐T(hightemperaturedifferences)chillwaterdesignispossibleinblockFwithoutanycost increasebecausetheexistingAHUwasdesignedforahighercoolingload.All theAHUinBlockFwasreplacedabout7~8yearsback.Duetothereasonthatthebuildingoccupantswerecomplainingthatthebuildingair‐conditioningwasnotcoldenough,thenewAHUsuppliedwasupsized.Unfortunately,thechillerremainsthesame,therefore,thebuildinghaveAHUcapacitythatdoesnotmatchthechillercapacity.WiththeexistingAHU,thesupplyairflowrateandthecoolingcoilwasoversizedforthecurrentreducedcoolingcondition.Aquickcheckwasdoneontheexistingcoolingcoilconfigurationbyassuming a typical design condition at that point of time. It was found that due to theimprovementsmadetothebuilding(loweringthetotalcoolingcapacity),theexistingcoolcoilshould be able to provide higher leaving chillwater temperature if the controls areworkingappropriately.This feature would requires the control valves to operate properly at the cooling coil,controllingthechillwaterflowrateaccuratelytoprovidetherightoff‐coiltemperatureforboththeairandwaterside.

56

3.15CASE13:FIXDUCTLEAKAGES,REBALANCEAIRFLOWGeneralDescriptions

Theexistingsupplyairductsysteminthisbuildingisknowntobeleakingbecausethe measured air temperature in the AHU room is colder than the office roomswheretheairisbeingsupplied.Thisindicatesthatthesupplyairflowisleakinginthefalseceilingwhichisalsothespaceforfree‐returnoftheairbackintotheAHUroom.

Onaveragethereisameasured1°CdifferencebetweentheairtemperatureintheAHUroomandtheofficerooms.

Details In the simulation model, the air leakage from the duct was calibrated to have aleakage rate of 20% to maintain a 1°C difference between the office roomtemperatureandAHUroomtemperature. This leakagewasmodeledasaby‐passductcircuitdirectlybacktotheAHUroom.

Inthiscasestudy,theleakageisstoppedtotally,pushingthetotalairflowintotheair‐conditioned spaces. Several calibrations were made between the zones tomaintain similar air temperature between the different zones. This would beequivalenttoconductingairbalancingatthediffuserstobalancetheairflowratetomaintainthecorrectairtemperatureineachzone.



‐0.4%



ProposedLifeTime 8


‐60/m2ofACfloorarea

Remarks:The air‐temperature in the offices dropped to 22.5°Cwhen the air leakages in the ducts arefixed. This actually followed the temperature set point as at the AHU room. Therefore, uponfixing the duct leakages, the air temperature should be reset as well to ensure that the air‐conditionedspacesarenotovercooled.

57

3.16CASE14:INCREASETEMPERATURESET‐POINTGeneralDescriptions

The existing temperature set‐point of 22.5°C is now providing the room withtemperatureof22.5°C insteadof23.5°Cwhentheductwas leaking.Aresettingoftheairtemperatureset‐pointismadeinthiscase.

Details Theset‐pointtemperatureintheAHUisnowraisedto23.5°Ctomaintaincomfortcondition.



1.0%



ProposedLifeTime 8


RM160/m²ofACfloorareaThisfeatureisfree.

Remarks:Anetsavingof0.6%ismadebyfixingtheduckleakagesandresettingtheairtemperaturesetpointat theAHU. Inaddition, thisalso indicate that it isnowpossible to reduceair flowratesuppliedtotheair‐conditionedspacesbecauseitwaspossibletomaintaincomforttemperatureevenwith80%ofthesuppliedairflowrate.

58

3.17CASE15:REDUCEAHUSUPPLYAIRFLOWRATEGeneralDescriptions

Existing AHU (air handling unit) delivers 5,737 l/s of cold air. After fixing thebuilding air‐tightness, improved the lighting power density and fixing the ductleakageitisnowpossibletoreducetheairflowratewhilestillbeingabletoprovideadequatecoolingtotheroom.

ResizingoftheAHUflowratewascomputedforthisnewscenario.Itwasfoundthatflowratecanbereduced to3,753 l/sor35%reduction fromtheexistingair flowrate.

Details ThesupplyairflowratefromtheAHUisreducedto3,753l/sforeachAHU.

Uponreducingtheair flowrate, the fantotalpressurewasalsoreduced followingthefanaffinity’slawwhichisthesameaspumpaffinity’slaw.

Thefanaffinitylawsaysthat,Withfandiameter(D)heldconstant:Law1a.Flowisproportionaltoshaftspeed:

Law1b.PressureorHeadisproportionaltothesquareofshaftspeed:

Law1c.Powerisproportionaltothecubeofshaftspeed:

where Q is the volumetric flow rate (e.g. CFM, GPM or L/s),

N is the shaft rotational speed (e.g. rpm),

H is the pressure or head developed by the fan/pump (e.g. ft or m or Pa), and

P is the shaft power (e.g. W).



11.5%



ProposedLifeTime 8


RM36,000/ahu

Remarks:Therearethree(3)optionstoreducetheairflowrateattheAHUatBlockF:

59

Option1Reducethepulleysizeatthemotoror/andincreasethepulleysizeatthefan.

Option2InstallaVSD(variablespeeddrive)toreducefanspeed.

Option3Changethefanandmotorcombinationtomatchnewrequirement.Theaffinitylawholdstruewhenthepump/fanefficiencyisthesame(orclosetothesame)atthesedifferentoperatingpoints.I.e.thepump/fancurvesneedtobecheckedtoconfirmthattheefficiency is still the same at the different operating point. Unfortunately, this checkwas notpossible in this study because the pump/fan curves for the AHU and pumps are no longeravailable. However, using the affinity’s law as it is for this study should be quite accuratebecausethestaticheadwouldbesomewhatlowatlowflowrate,allowingittofollowthesameefficiencycurveastheflowratereduceswhichistypicaloffan/pumpcurves.

60

3.18CASE16:LOWLOSTAIRFILTERSGeneralDescriptions

PressuredropthroughairfilterinAHUisacauseofenergyconsumptioninfan.Thehigherthepressuredrop,themoreenergyisused.

Most type of electronic air‐filters and certain type of mechanical air filters aredesignedtohavelowpressuredrop.Itisquitecommontofindelectronicairfiltersthathaveapressuredropof80PalessthantypicalmechanicalairfilterforuseinAHU.

Details ThefanpowerconsumptionwasmeasuredinkWoffanpowerused.Thisfanpoweristhenconvertedintofantotalpressurebyassumingthatthetotalfanefficiencyis60%. A fan total efficiency of 60% is typical of backward curve fans usingconventionalmotors.

With this assumption, the base building was computed to have an average fanpressureof539Paat themeasuredaverage flowrateof5737 l/sofair flowrate.Thereductionofflowrateto3,753l/swouldreducethefantotalpressureto231Pausingthefanaffinity’slaw.

Inthiscasethetotalpressureofthefanisreducedfurtherby80Pato150Pa.



1.5%



ProposedLifeTime 8


4,750/ahu

Remarks:There is a certain amount of uncertainty of the base scenario total pressure loss by the fansbecausethiswasnotmeasuredbytheenergyauditor.Anassumptionwasmadethatthetotalfanefficiencyis60%tocomputethetotalpressurelossbythefan.Ifthetotalfanefficiencyishigher than 60%, the total pressure loss would be higher than the 539 Pa. If the total fanefficiencyislowerthan60%,thetotalpressurelosswouldbelowerthan539Pa.According to the fan affinity law, reducing the air flow rate by 35%would reduce the totalpressureby58%,thereforereducingthiscasescenariototalpressurelossofthefanto230Pa,whichmayseemverylowtosomepracticingengineers.However,thetotalfanefficiencyof60%wouldhaverequirementofabackwardcurvefanefficiencyof70%withamotorefficiencyof89%andabeltefficiencyof97%.Fora7~8yearoldAHU,theseefficiencynumbersseemstoberather realistic and conservative (the actual case may even have lower total fan efficiencybecauseenergyefficiencywasnotwell‐knownyet).Therefore,thecomputedtotalpressurelossofthefanfromthepowerconsumptionshouldbefairlyaccurate.Onreflection,thepressurelossthroughtheoriginalairfilterisreducedasperthefanaffinity’slawaswellwithreductionofairflowrate.Thepressurereduction,byusingalowpressurelostair filter such as electronic air filter, of 80 Pa should also be reduced by 58% following the

61

affinity’slaw,i.e.apressuredropof34Paonlyduetothelowerairflowrate.Therefore,totalfanpressureinthiscaseshouldbe231–34=197Pa.Thetotalpressureusedinthisstudyof150Paisnotcorrectandis24%lowerthanitshouldbe.Thereforetheresultprovidedbythiscaseisnotcorrectatthisstage.Anothersetofsimulationwillbeconductedatalaterstagetocorrectthissimulationcasestudy.

62

3.19CASE17:FANEFFICIENCYGeneralDescriptions

Backwardcurvefanwithanefficiencyof60~70%attheflowrateof3200to6000l/s iscommonlyusedtodaybythebuilding industry.However, in thepastseveralyears,airfoilfanisgettingpopularinthemarketandthesefansprovideefficienciesupto85%forcertainmodelandflowrates.

With a fan efficiency of 85%,motor efficiency of 90%and a fan belt efficiency of97%, a total fan efficiency of 74% was possible. A conservative assumption ofimprovingthefantotalefficiencyto70%wasmadeforthiscasestudy.

Details Thefantotalefficiencywasimprovedfrom60%to70%efficiency.



0.4%



ProposedLifeTime 8


1,200/ahu

Remarks:There is notmuchof a case to improve the fan efficiency further as the savings providedbyupgradingtoanairfoilfanprovidesverylowreturninthisstudyforblockF.Themainreasonforthislackofenergysavinginthiscaseisbecausetheflowrateisquitelowandtotalpressurelossisactuallylowaswell.Duetothesereasons,theimprovementonthefanefficiencyhasverysmallimpactonthesavingsthatcanbefurthergained.

63

3.20CASE18:VAVSYSTEM,OFFCOILTEMP14°CGeneralDescriptions

Thebasebuildingair‐sideair‐conditioningsystemusesConstantAirVolume(CAV)system.TheCAVsystemdeliversairataconstantflowratetotheroom;theroomtemperature is then regulated by supply air temperature. If the room is cold, thesupplyairtemperatureisincreasedtomaintaintemperatureatcomfortablelevel.Ifthe room is hot, the supply air temperature is reduced to cool the room to acomfortablelevel.

AVariableAirVolume(VAV)systemdeliversairataconstantairtemperaturetotheroom; the room temperature is then regulated by the supply air flow rate. If theroomiscold,thesupplyairflowrateisreduced.Iftheroomishot,theflowrateisincreasedtocooltheroomtothecomforttemperaturesetpoint.

TheadvantageoftheVAVsystemisthatitreducesfanenergyusewhenthebuildingisrunningonpartloadbecausethefanspeedisreduced.

AVAVsystemhastwoadditionaldevicesadditionaltoaCAVsystem.ThesearetheVAVBox (orBoxes)withamotoriseddamper to control the flowrate into roomsdependingon themonitoredair temperature, andavariable speeddrive (VSD) tocontrolthespeedoftheAHUfan’smotordependingonthepressuresensedintheduct.WhentheVAVdamperopenformoreflowrateintotheroom,thepressureintheductdrops, theVSD sensing adrop inpressurewill increase the speedof themotortoincreaseairflowratetomaintainthepressureintheductataparticularset point. When the VAV damper close to reduce flow rate into the room, thepressure in theduct increase, theVSDsensingan increase inpressurewill reducethespeedof themotor toreduce theair flowrate tomaintain thepressure in theductataparticularsetpoint.

Details AVAVsystemwasmodeledforthebuilding,witheachAHUhavingapeakflowrateof3,753l/sat150Pa.

Offcoiltemperaturewassetat14°Cinthiscasescenario.

Aminimumairflowrateof30%ofthepeakflowratewasalsoset.



0.1%

64



ProposedLifeTime 5


RM150/ahu

Remarks:TheenergyefficiencygainfrominstallingaVAVsysteminthisbuildingisquitelowduetothereasonthatthefanpowerisalreadyverylowasitisnow,duetothelowairflowrateandlowtotal pressure loss. The low flow rate is a cause of the lower building load from theimprovementmadeon thebuildingair‐leakages, lower lightingpowerconsumptionand fixedductleakages.Itshouldbehighlightedherethatthereisasortofdominoeffectofconductingenergyefficiencyinexistingbuilding,whereimprovementmadeearlieronthebuildingallowsbetterefficiencytobemadetotheAHUandalsoonthechillwatersystemaswell.Thisisbecausethebuildingair‐conditioning system was sized for a larger cooling load. When the building cooling load isreduced, the existing pipes and ducts became ‘oversized’, providing very low pressure loss,reducingpowerconsumptionsignificantlyasprojectedbythepump/fanaffinitylaw.Ofcourse,this efficiency gain can only be “claimed” when the pumps and fans flow rate are actuallyreducedinpractice.

65

3.21CASE19:VAVSYSTEM,OFFCOILTEMP16°CGeneralDescriptions

The simulation result of Case 18 showed that the air‐conditioned space relativehumiditywas reduced fromanaverageof70%to60%.This reductionof relativehumidityalsoincreaseschillerenergyusedbecausemoreenergyisusedtoremovemoisturefromtheair(latentload).

AcheckonearliersimulationcasesrunningonCAVsystemshowedanaverageoff‐coil temperature of 17~18°C. Due to this high off coil temperature, themoisturecontentintheairisstillrelativelyhighcausing,thefairlyhighrelativehumidityof70%assimulatedandmeasuredatsite.

Increasingtheoffcoiltemperaturefrom14°Cto16°Callowslessdehumidificationat the cooling coil, thus providing energy reduction on latent heat removal.However,attheoff‐coiltemperatureof16°C,theairflowratehastobeincreasedforit tobeable toremoveadequatesensibleheat fromtheair.This increases the fanenergyusage.

Thiscasestudyistotesttheoverallbenefit(orloss)byreducingmoistureremovalwhile increasing fan energy use by the AHU system by increasing the off‐coiltemperatureto16°C.

Details Offcoiltemperaturewassetat16°C.

Aminimumairflowrateof30%ofthepeakflowratewasset.



0.5%



ProposedLifeTime 5


RM930/ahu

Remarks:Increasingtheoff‐coiltemperatureto16°Cincreasesthefanpowerincase19ascomparedtocase 18 where the off‐coil temperature was set at 14°C. However, the reduction of chillerenergyincase19ishigherthantheincreaseinfanenergyused,providinganoverallsavingtothe air‐conditioning system. This feature does not require any additional cost to beimplemented.ItshouldalsobenotedthisstrategyworkedforBlockFatthisstagebecausethefanenergyusagesisrelativelylowduetothelowtotalpressurelossandthe“oversized”ductduetolowerflowraterequirement.Two(2)chartsareprovidedbelowtoshowthetotalenergyconsumptionofthechillerandfanenergyfromalltheAHUinBlockF.Where,

o Case17isaCAVsystemo Case18isaVAVsystemwithoffcoiltemperatureof14°Co Case19isaVAVsystemwithoffcoiltemperatureof16°C

66

As shownbyboth the chartsabove, the fanenergy increasesby~9MWh/year for theentirebuildingduetothehigheroffcoiltemperaturesetpointwhilethechillerenergyreducesby~22MWh/year.

67

3.22CASE20:INCREASELIFTLOBBYTEMPERATURETO26.5°CGeneralDescriptions

The installationofaVAVsystemmakes it iseasiertoregulatetemperaturewithinthezonewiththeuseofmotorizeddampercontrolledVAVboxes.

Inatransitionalspacesuchasliftlobby,itisnotnecessarytokeepthesespacesat23.5°C. The VAV box supplying to this space can be adjusted to maintain an airtemperature of 26.5°C at this zone to reduce energy consumption for the entirebuilding.

Details AirtemperaturesetpointforLiftLobbywas setto26.5°C



0.3%



ProposedLifeTime 5


RM550/ahuThisisanocostfeature.

Remarks:This is a very simple solution to provide an additional 0.3% savings to the building energyconsumption.ItshouldalsobenotedthatevenwiththeexistingCAVsystem,thisfeatureisalsopossibletobeimplemented,byreducingtheflowrateintotheliftlobbybyremovingdiffusersorbyclosingthediffuserdamperstoreducetheflowrateforthiszone.

68

3.23CASE21:CHILLEREFFICIENCYGeneralDescriptions

TheexistingchillerinBlockFwasmeasuredandthencalibratedbacktothetypicalchillerratingconditionbyEnergyAuditor.ThereportshowedthatoneofthechillerhasaCOPof4.3(0.82kW/ton)andanotheroneaCOPof4.88(0.72kW/ton). Atanymomentoftime,onlyone(1)chillerwasrunning.These2chillerswererunonalternatedays,givingopportunityforeachofthechilleradayofrest.

Details Itwilltakealotoftimeandefforttoconfigurethesimulationsoftwaretosimulatealternate chillers running every day. Due to the limited time available for thisproject,onlyonechillerismodeled.

The calibrationof the chiller efficiencywasmadebased on all themeasureddatausedforthebuildingenergymodel,suchasthemeasuredsmallpowerload,lightingload, infiltration (fresh air), no of people and etc. It was found that a simulationchiller COP of 4.88 (0.72 kW/ton) matches perfectly with the measured annualelectricalenergyconsumptionofthechiller.

Duetothereasonthatthemeasuredsupplychillwatertemperatureisonaverage10.5°Cinsteadofthetypical6.7°C(44°F),theactualaveragesimulatedCOPduringoperationwasat5.1(0.69kW/ton)althoughtheratedconditionCOPis4.88(0.72kW/ton).

The existing building is using single stage screw chiller. The chiller performancecurveused for thesimulationbuildingupto thisstage isbasedona typicalsinglestage screw chiller provided by US Department of Energy (DOE) for their Equestsoftware. The DOE chiller curve fit that accounts for the condenser returnwatertemperature, chill water supply temperature and part‐load performance of thechillertocomputetheCOPofthechiller.

Incase21,anenergyefficientcentrifugalchillerwasselectedtohavearatedCOPof6.3(0.56kW/ton).Againthechillerperformancecurveusedforthischillerisbasedon DOE curve‐fit for a centrifugal chiller that accounts for the condenser returnwater temperature, chill water supply temperature and part‐load performance ofthechiller.



5.6%



ProposedLifeTime 15


RM556,000perchiller2noofchillersforbuilding

Remarks:ImprovingthechillerCOPprovidesahighenergyreductionof5.6%tothebuilding.Tochange2chillers,at380tonperchiller,thecostwouldbeapproximatelyRM1.3millionperchiller.Thebudgetfromthesavingsasprovidedbythisstudyallowsapproximately50%ofthechillertobesubsidiesbythesavings.I.e.thebuildingownerisonlypayinghalfpriceforthenewchillerdue

69

totheefficiencygainachievablebythenewchiller.In addition, studies in Case 51 & 52 showed that if the building did not embark on energyefficiency, the chiller capacity that is required to provide adequate comfort to the existingbuilding scenario is a 1,000 ton chiller. A 1,000 ton chillerwould cost approximatelyRM3.5millionper chiller.Thenewchiller requirementafteroptimizing thebuilding isonly410 ton,costingonlyRM1.4millionperchiller.This indicatesthatabudgetofRM2.1millionissavedper chiller. For 2 chillers, the saving is RM 4.2million to replace both the old chiller in thisbuilding.

70

3.24CASE22:VARIABLESPEEDCHILLERGeneralDescriptions

Chillerfittedwithvariablespeeddriveisalreadyavailableinthemarkettoday.VSD(variablespeeddrive)chillerwouldtypicallyhavehigherefficiencyatpart‐loadof30%to60%ascomparedtoatypicalscreworcentrifugalchillerwithoutvariablespeed.

In climates with hot and cold seasons, VSD chiller has been shown to have COPabove 10.0 during season of low wet‐bulb temperature at part load scenario.Unfortunately in Malaysia climate, where the wet‐bulb temperature is fairlyconstantthroughouttheyear,theseVSDchillerswouldtypicallymaintains(orjustmarginallybetterthan)thepeakloadCOP.

In theexistingbuilding scenario,one (1) chiller isused for theentiredayofpeakload andpart load condition.Theuseof VSD chillerwouldhelp toprovidebetterperformanceduringpart‐loadcondition.

Details The DOE VSD centrifugal chiller performance curve fits was used to model thischiller for this case. A rated peak condition COP of 6.3 (0.56 kW/ton) wasmaintainedforthisstudy.



1.8%



ProposedLifeTime 15


RM178,500/chillerBudgettoupgradetoVSDchiller

Remarks:TheVSDchillerwouldbeafeasibleoptionforBlockF,ifthecostofVSDchillerisnotmorethanRM178,500foratypicalcentrifugalchillercost.

71

ThesimulationofcentrifugalVSDchillershowedmarginallybetterperformancethanatypicalcentrifugalchilleratpeakload.Howeveratpartloadofbelow50%,theVSDchillersoutperformthecentrifugalchillerbyabiggermargin.InthecaseofBlockF,thereisagoodreasonforusingaVSDchillerbecauseonlyonechillerisrunatanyonetime(evenatpartloadcondition).TheVSD chillers will provide better efficiency at part load conditions as compared to a typicalcentrifugalchiller.However, chiller performance is actually quite specific to themanufacturer. This VSD chillercurvefitprovidedbyDOEmaynotmatchallVSDchillersfromalldifferentmanufacturers.Itisrecommended to study each manufacturer chiller curve fit individually to get the bestperformanceandatthebestvalueofinvestmentforthisbuilding.

72

3.25CASE23:CONDENSERFLOWRATE2.5GPM/TONGeneralDescriptions

Chillercanberunwithcondenserflowrateof3gpm/ton,2.5gpm/tonoraslowas2.0 gpm/ton of chiller load. The lower the flow rate of condenser water, theefficiencyofthechillerbecomeslower.However,reducingthecondenserflowratewillreducethecondenserpumppowerbyacubicrelationship(pumpaffinity’slaw).

Thisstudyistocomparewhichfactorismoreimportantforthisbuilding,thechillerefficiencyversusthecondenserpumppower.

Details The flow rate of the condenser water was reduced from from 3 gpm/ton to 2.5gpm/ton.



1.3%



ProposedLifeTime 8


2existingcondenserpumpsinplantroom67,000/pump

Remarks:Casestudy23and24showedthatitispossibletoreducethecondenserflowratedownto2.0gpm/tonwithimprovementtotheoverallenergyefficiencyofBlockF.Thismayormaynotbereplicated for all buildings, as itwouldbedependent on the existing condenserpumppowerconsumptionandtheexistingchillerperformancecurve.This study uses chiller performance curve provided byDOE (USDepartment of Energy) thatwould account for the reduction of condenser water flow rate, therefore, the loss ofperformanceby the chiller is captured as shownby the chart belowof the simulatedCOP ofchillerofthecasewith3gpm/tonand2.5gpm/tonofcondenserflowrate.

73

Theexistingbuildingcondenserpumphasapumpheadof23.1mofwater.Areductionoftheflowrate to2.5gpm/ton reduces thepumphead to16.1mofwater andat2.0 gpm/ton, thepumpheadisthenreducedto10.3mofwater.Atthelowestpumphead,thepumppowerhasreducesby70%fromtheexistingcondition.Thesenumberswereallcomputedusingthepumpaffinity’slaw.

75.3

23.1

42.0

62.8

16.124.3

50.2

10.3 12.4

0

10

20

30

40

50

60

70

80

l/s head m kW

Condenser gpm/ton Options

3 gpm/ton 2.5 gpm/ton 2 gpm/ton

74

3.26CASE24:CONDENSERFLOWRATE2.0GPM/TONGeneralDescriptions

Chillercanberunwithcondenserflowrateof3gpm/ton,2.5gpm/tonoraslowas2.5gpm/ton.Thelowertheflowrateofcondenserwater,theefficiencyofthechillerbecomes lower. However, reducing the condenser flow rate will reduce thecondenserpumppowerbyafactorof3.

Thereforethisstudyistocomparewhichfactorismoreimportantforthisbuilding,thechillerefficiencyversusthecondenserwaterflowrate.

Details Reducing the flow rate of the condenserwater from2.5 gpm/ton to 2.0 gpm/tonreducesthepumppeakpowerfrom



0.4%



ProposedLifeTime 8


AdditionalRM22,800/pump

Remarks:Casestudy23and24showedthatitispossibletoreducethecondenserflowratedownto2.0gpm/tonwithimprovementtotheoverallenergyefficiencyofBlockF.Thismayormaynotbereplicated for all buildings, as itwouldbedependent on the existing condenserpumppowerconsumptionandtheexistingchillerperformancecurve.This study uses chiller performance curve provided byDOE (USDepartment of Energy) thatwould account for the reduction of condenser water flow rate, therefore, the loss ofperformanceby the chiller is captured as shownby the chart belowof the simulatedCOP ofchillerofthecasewith3gpm/tonand2.5gpm/tonofcondenserflowrate.

75

Theexistingbuildingcondenserpumphasapumpheadof23.1mofwater.Areductionoftheflowrate to2.5gpm/ton reduces thepumphead to16.1mofwater andat2.0 gpm/ton, thepumpheadisthenreducedto10.3mofwater.Atthelowestpumphead,thepumppowerhasreducesby70%fromtheexistingcondition.Thesenumberswereallcomputedusingthepumpaffinity’slaw.

75.3

23.1

42.0

62.8

16.124.3

50.2

10.3 12.4

0

10

20

30

40

50

60

70

80

l/s head m kW

Condenser gpm/ton Options

3 gpm/ton 2.5 gpm/ton 2 gpm/ton

76

3.27CASE25:PRIMARY/SECONDARYCHILLWATERFLOWGeneralDescriptions

The existing building uses a constant chill water flow rate at the moment. Mostchillersrequiresconstantflowchillwaterflowrateforittooperatesafelywithoutcausing the chiller to ‘trip’. Single primary only constant flow chill water iscommonlyprovidedfromthechillertotheAHUinthebuildingsduetoitssimplicityin design. However, this kind of constant flow system is designed for the peakcooling loadof the year, therefore the system isdesigned at thehighest flow raterequiredtocoolthebuilding.Constantprimaryflowchilledwaterwillcontinuestoflowatthefullrateevenwhenthebuildingisrunningonpartload.

Thereisapossibilitytoprovideconstantflowtothechillerwhileprovidingvariableflow to the AHU using a pipe configuration system called primary‐secondaryvariable flow system. The primary pump system refer to the pump/piping circuitrecirculating the chillwater at a constant flow to the chiller,while the secondaryvariablepumpsystemrefertothepump/pipingsystemthathaveavariablespeeddrive(VSD)onthepumpthatwilltrytomaintainthepipepressuretodeliverchillwaterattheflowrateasneededbythebuilding’sAHUload.

Energy is saved during part load condition when pump power is reduced in thesecondarypumptomatchthepartloadrequirementoftheAHUload.

Details Aconstantflowprimarypumpwithaheadof15mwaterwasspecifiedforthiscasescenariowithavariablesecondarypumpwithaheadof7mwaterwasspecified.Thelowheadatthesecondarypumpwasduetothelowerchilledwaterflowrateappliedinearliercases.



0.0%


RinggitSaved(RM/year) ‐300

ProposedLifeTime 8


‐1,200perchillerset

Remarks:There is no energy efficiency gain from installing a primary‐secondary chill water pumpingsystemforthisbuilding.Theinstallationofprimary‐secondarypumpsystemrequires2setsofpumps to be installed. The 1st set provides constant flow into the chiller while the 2nd setprovidesvariableflowtotheAHU.Oncloserinspectionofthesimulationresults,thecoolingloadofthebuildingwassimulatedtobe somewhat consistently stable. Itbasically showed that theenergy savingsprovidedby thesecondaryvariablepumpduringpartloadwasoffsetbythe1stsetofprimarypumpforconstantflowthroughthechiller.Againitshouldbenotedthatthechillwaterflowratehasbeenreducedinearliercasesandthepumppowerforchillwaterflowisfairlylownowduetothepumpaffinitylaw.

77

3.28CASE26:PRIMARYVARIABLECHILLWATERFLOWGeneralDescriptions

Inthepast,almostallchillersrequireconstant flowofchillwater for it tooperatewithout any problem. These days, chiller manufacturers have been able toincorporateprimaryvariableflowfortheirchillers.

Thisfeaturereducesinitialcostbecauselesspumprequirement(ascomparedtoaprimary/secondarysystem)andreducesoperatingcostaswellduetoreducedchillwater flow rate (i.e. it is not required to circulate the full flow rate through thechilleratpartloadconditionanymore).

Details Variableprimaryflowwasmodeledforthiscase.



0.1%



ProposedLifeTime 8


RM5,250/pump2chilledwaterpumpsinbuilding

Remarks:Variableprimaryflowrequires2itemsforittowork.One,avariablespeeddrive(VSD)onthechillwaterpumpand two, a chiller that can accept variable chillwater flow.All VSD chillersallow variable chilledwater flow, however only a couple ofmanufacturer of non‐VSD chillerallow variable chilledwater flow through it. Therefore, it is important to check if the chillerwouldallowforthistechnologytobeimplemented.Inthiscasestudy,itisshownthatenergysavingprovidedbythisfeatureismarginal.However,thecomputedbudgetavailableshouldbeadequatetopayfortheVSDforthepump.Therefore,as long as the chiller can accept variable chilled water flow, it is recommended to install aprimaryvariablepumpingsystem.

78

3.29CASE27:CHILLEDWATERPUMPEFFICIENCYGeneralDescriptions

Pump efficiencies provided by the Energy Efficiency Guideline in Malaysia(publishedbyPusatTenagaMalaysia),isasshownbelow.

Flow (gpm) Efficiency [%]

End Suction (incl. vertical & close impeller types)[%]

Horizontal / Vertical split casing (centrifugal and close impeller types)[%]

Vertical multistage & Horizontal multistage / Close Coupled (close impeller types) [%]

Submersible (semi open and open impeller types) [%]

Process Pump (open impeller types) [%]

100 50 – 60 - 55 – 75 48 – 55 48 – 52110 – 250 65 – 75 73 – 76 68 – 75 48 – 55 48 – 52300 – 450 75 – 80 75 – 79 70 – 75 55 – 65 48 – 52460 – 600 78 – 82 75 – 79 55 – 65 48 – 52700 – 1000 80 – 85 78 – 82 65 – 72 48 – 521100 – 1500 83 – 87 78 – 82 60 – 68 - 1600 – 2500 83 – 87 78 – 83 60 – 70 - 2600 – 3600 - 80 – 86 70 – 75 - 3700 – 4000 - 82 – 86 75 – 80 - > 5000 - 80 – 88 75 – 80 - Foraflowrateof1100to1500gpm,apumpefficiencyof83to87%isshowntobeavailableinthemarket.

Details Itwas possible to compute the pump total efficiency (motor andpump) from themeasured flowrate,pumpheadandpowerconsumptionof thepumpmotor. Thepumptotalefficiencycomputedwas40%fromthemeasurednumbers.

Assuming that the motor efficiency is at 80%, the existing pump efficiency iscomputedtobe50%.

Inthiscasethechilledwaterpumpefficiencywasraisedto85%.


Energy SavedkWh/year/m²(%)

0.3%



ProposedLifeTime 8


RM14,300/pump2existingchillwaterpumpinplantroom

Remarks:Thecomputedchillwaterpumpefficiencyof50%isquite low,even fora20yearsoldpump.Furthercheckreviewedthattheminimumstraightlengthofpipeof5~6pipediameterbeforethesuctionofpumpisnotfollowedintheexistinginstallationasshownbythepicturesbelow.

79

This installationmistake causes the efficiency of the pump to be lower than it should be. Itshouldalsobenotedthatthismistakeisalsoseeninmanynewbuildingsandseemstobeoneofthebadindustrypracticethatneedtobeaddressed.ThebudgetavailabletoimprovepumpefficienciesisapproximatelyRM14,300perpump.Thiswouldapproximatelycover theentirenewpumpcost.However, theearlier reductionof flowrateprovided amuchhigherbudget to replace thepump in the1st place.Therefore, this is abudgettochooseabetterefficiencypump.

80

3.30CASE28:CONDENSERWATERPUMPEFFICIENCYGeneralDescriptions

Pump efficiencies provided by the Energy Efficiency Guideline in Malaysia, is asshownbelow.

Flow (gpm) Efficiency [%]

End Suction (incl. vertical & close impeller types)[%]

Horizontal / Vertical split casing (centrifugal and close impeller types)[%]

Vertical multistage & Horizontal multistage / Close Coupled (close impeller types) [%]

Submersible (semi open and open impeller types) [%]

Process Pump (open impeller types) [%]

100 50 – 60 - 55 – 75 48 – 55 48 – 52 110 – 250 65 – 75 73 – 76 68 – 75 48 – 55 48 – 52 300 – 450 75 – 80 75 – 79 70 – 75 55 – 65 48 – 52 460 – 600 78 – 82 75 – 79 55 – 65 48 – 52 700 – 1000 80 – 85 78 – 82 65 – 72 48 – 52 1100 – 1500 83 – 87 78 – 82 60 – 68 - 1600 – 2500 83 – 87 78 – 83 60 – 70 - 2600 – 3600 - 80 – 86 70 – 75 - 3700 – 4000 - 82 – 86 75 – 80 - > 5000 - 80 – 88 75 – 80 - For a flow rate of 1100 to 1500 gpm, a pump efficiency of 83 to 87% should beavailableinthemarket.

Details Itwas possible to compute the pump total efficiency (motor andpump) from themeasured flowrate,pumpheadandpowerconsumptionof thepumpmotor. Thecondenserpumptotalefficiencywasalsocomputedtobe40%fromthemeasurednumbers.

Assuming that the motor efficiency is at 80%, the existing pump efficiency iscomputedtobe50%.

Inthiscasethecondenserwaterpumpefficiencywasraisedto85%.



0.4%



ProposedLifeTime 8


21,800/pump2existingcondenserwaterpumpinplantroom

Remarks:Thecomputedcondenserwaterpumpefficiencyof50% isquite low,even for a20yearsoldsystem.Furthercheckreviewedthattheminimumstraightlengthofpipeof5~6pipediameterbeforethesuctionofpumpisnotfollowedintheexistinginstallationaswiththechilledwaterpump.This installationmistake causes the efficiency of the pump to be lower than it should be. Itshouldalsobenotedthatthismistakeisseeninmanynewbuildingsaswellandseemstobe

81

oneofthebadindustrypracticethatneedtobeaddressed.ThebudgetavailabletoimprovecondenserpumpefficienciesisapproximatelyRM21,800perpump. This should cover the entire new pump cost. The budget is higher for the condenserpumpascomparedtothechilledwaterpumpwasduetothereasonthatthecondenserpumphasahigherflowrateandhigherpumpshead.Therefore,theimprovementtotheefficiencyofthecondenserpumpprovidedhighersavingthanimprovementtotheefficiencyofchilledwaterpump.

82

3.31CASE29:PUMPMOTOREFFICIENCYGeneralDescriptions

TheEFF1,motorefficiencyfor7.5kW,islistedbytheEnergyEfficiencyGuidelineinMalaysiatobehigherthan90.1%.

Details The existing assumption of 80% for both the chilled water pump motor andcondenserwaterpumpmotorwasimprovedto90%forthissimulationcase.



0.1%



ProposedLifeTime 8


RM2,860/motor(4motorstotal)2chillwaterpumpmotor

2condenserwaterpumpmotorRemarks:TheavailablebudgetofRM2,860permotorshouldbemorethanadequatetopayforahigherefficiencynewmotorwithefficiencyhigherthan80%.Motor efficiency is not exactly constant at different part load. A sample efficiency curve of amotorisprovidedbelow.Motorefficiencyisfairlyconstantfromfullloaduntil30%ofthefullload.Atlessthan30%ofmotorfullload,themotorefficiencydropsignificantly.

83

3.32CASE30:COOLINGTOWEREFFICIENCYGeneralDescriptions

TheMalaysianEnergyEfficiencyandConservationGuidelineforMalaysianIndustryprovidedthefollowingdatafora600HRTcoolingtower.

CoolingTowerType Size (NominalHRT)

(kWe/HRT) @ PumpHead(m)

ROUND COUNTERFLOWSINGLECELL

600 0.025 5

SQUARE COUNTERFLOWSINGLECELL

600 0.0357 3.7

SQUARE COUNTERFLOWMULTICELL

600 0.025 3.4

SQUARE CROSSFLOWSINGLECELL

600 0.0294 4.4

SQUARE CROSSFLOWMULTICELL

600 0.0275 3.3

Details Thecooling tower inBlockFbuildingwasmeasured toconsume0.0599kW/HRTfor theexisting cooling tower.This corresponded to themeasured19.4kWof fanpowerusedbythecoolingtower.

Inthissimulationcase,thecoolingtowerpowerconsumptionisreducedto0.0275kW/HRT.Thisreducesthefanpowerto10kW.



0.7%



ProposedLifeTime 8


RM35,000/coolingtower2coolingtowers

Remarks:The cooling tower was measured to consume 3.6% of the building air‐conditioning systemenergy consumption as shown in the table below. However, due to its inefficiency, it waspossible to reduce the cooling tower energy consumption by 50% using the latest energyefficientcoolingtoweravailabletoday.

84

Thenewdataavailablefromthepublishedenergyefficiencyguidelineshowedthatitispossibleto reduce the cooling tower fan consumption by half as shown in the table provided in thegeneral descriptions. Care should be taken when selecting cooling tower to ensure that theefficiency gain by the fan is not at the expense of the pump head. The energy caused by thepumphead canbe computedusing the condenser flowrate andpump total efficiency for thecoolingtower.

85

3.33CASE31:VSDONCOOLINGTOWER,30.5°CGeneralDescriptions

Avariable speeddrive (VSD) canbe install on the cooling tower fan to reduce itsspeedwhenthetemperatureset‐pointofthereturncondenserwatertothechillerisachieved. This is done by installing a temperature probe on the bottom of thecoolingtower,measuringthetemperatureofthewateratthebottomofthecoolingtower.Reducing the fan speedwill reduce fanenergyconsumptionby the coolingtower.

However, the lower the temperature of condenser water returning back to thechiller, the more efficient the chiller will become. Similarly, a higher condenserwatertemperatureisreturnedtothechiller,thechillerwouldbecomelessefficient.

In climate where the wet‐bulb temperature of the air changes drastically due toseasonalchanges,ithasbeenshownthatitisbeneficialtouseaVSDonthecoolingtower. However, in Malaysia hot and humid climate, where the wet‐bulbtemperatureisfairlyconstant,itisnotknownifitwillprovidethesameamountofsavings.

Therefore,casestudy31to36isatestonthepotentialbenefitofusingVSDonthecoolingtowerinthisclimatezone.

Details Avariablespeeddriveisspecifiedforthecoolingtowertoreducefanspeedwhenthereturncondenserwatertemperatureasreached30.5°C.



‐0.2%



ProposedLifeTime 8


RM‐9,300/coolingtower

Remarks:Cases31 to36 test thepotential of energyefficiencygainby the installationof aVSDon thecooling tower.ThisstudyonblockF indicates that itwouldnotbepractical to installVSDoncoolingtowerbecausetheefficiencylostbythechillerishigherthantheefficiencygainbythe

86

coolingtowerfan.However, this study is based on the chiller performance curve fit provided for a typical VSDcentrifugal chiller as provided by DOE (US Department of Energy) for their Equest (Doe‐2)software, provided free by the US government on their website. Actual chiller performancecurvefromeachmanufacturermaybeslightlydifferentandmayyielddifferentresult.

Thechartaboveshowstheannualheatrejection(coolingtower+condenserpump)energyassimulatedbythisstudy.Thecondenserpumpenergy isconstant inall thecasesshowninthechart above. Therefore, the energy differences between the cases are caused by the coolingtoweronly.Thehighestcoolingtowerfanenergyreductioniscase31,whereaVSDisusedtoreducefanspeedoncethecondenserreturnwatertemperaturereaches30.5°C.Cases ShortDescriptionsCase29 Anon‐efficientcoolingtowerCase30 AnefficientcoolingtowerCase31 VSDfittedoncoolingtowerwithsetpointtemperatureof30.5°CCase32 VSDfittedoncoolingtowerwithsetpointtemperatureof29.5°CCase33 VSDfittedoncoolingtowerwithsetpointtemperatureof28.5°CCase34 VSDfittedoncoolingtowerwithsetpointtemperatureof27.5°CCase35 VSDfittedoncoolingtowerwithsetpointtemperatureof26.5°CCase36 No VSD, but larger cooling tower with set point temperature of 25°C (i.e. get the

returncondenserwatertemperatureaslowaspossible).

Thechartbelowindicatesthatthelowertheset‐pointtemperatureforreturncondenserwateron the VSD for the cooling tower, the chiller energy consumption reduces further, indicatingthat the lower return condenser water temperature increases the efficiency of the chiller.Meanwhile,thechartaboveshowsthatthefanpowerofthecoolingtowerincreasesastheset‐point temperature is reduces, indicating that more fan power is required to achieve the setpoint temperature. At the set‐point temperature of 26.5°C the fan on the cooling tower ispracticallyrunningfullspeedatalltime.

87

Thechartbelowdisplaytheannualtotalchillwatersystemenergyusedforcases29to36.

It is therefore more practical to consider the overall chill water system energy efficiencyscenario thatwouldaccount forboth the cooling tower fanenergy, chillerenergyandpumpsenergyusedbythechilledwatersystemasshowninthechartabove.UsingaVSDonthecoolingtowerwithcondenserreturntemperaturesetpointof30.5°C(Case31)ismoreinefficientthantheconventionalcoolingtowerasinCase30.ThechilledwatersystemenergyreducesasthesetpointtemperatureforthereturncondenserwaterisreducedforthecoolingtowerwithVSDonit.Atthesetpointof26.5°C(Case35),thecoolingtowerfanispracticallyrunningfullspeedatalltime.This result indicates that it would be better to try to reduce temperature of the returncondenserwaterthantoreducethefanspeedofthecoolingtowerforbetterenergyefficiency.Incase36,anoversizedconstantspeedcoolingtowerisusedinsteadtotrytokeepthereturncondenserwatertemperatureaslowaspossibleatalltime.ThisseemstobepracticalsolutionastheenergyefficiencylostissignificantlysmallascomparedtoacoolingtowerwithVSDsetto26.5°C,becausethereisnoneedtoinstallaVSDontheoutdoorfanwhichmayhavehighercostduetoweatherproofingrequirementandperhapsmoremaintenanceissuesaswell.

88


ReadCase31.




0.3%



ProposedLifeTime 8


RM15,500/coolingtower

Remarks:Cases31to36testtheenergyefficiencygainpotentialforinstallingaVSDonthecoolingtower.This studyonblockF indicates that itwouldnotbepractical to installVSDoncooling towerbecausetheefficiencylostbythechillerishigherthantheefficiencygainbythecoolingtowerfan.ThisstudyisbasedonthechillerperformancecurvefitprovidedforatypicalVSDcentrifugalchiller as provided by DOE (US Department of Energy) for their Equest (Doe‐2) software,provided freeby theUS government on theirwebsite.Actual chillerperformance curve fromeachmanufacturermaybeslightlydifferent.Moredetailscanbefoundin“Remarks”sectioninCase31.

89


ReadCase31.




0.2%



ProposedLifeTime 8




90


ReadCase31.




0.1%


RinggitSaved(RM/year) 800

ProposedLifeTime 8


3,300/coolingtower


91


ReadCase31.




0.0%


RinggitSaved(RM/year) 500

ProposedLifeTime 8




92

3.38CASE36:OVERSIZEDCOOLINGTOWER,26.5°CGeneralDescriptions

Incase35,theVSDonthecoolingtowerhaveaset‐pointtemperatureof26.5°C.Theresultsshowedthatithasthelowestair‐conditioningsystemenergyconsumption.This showed that is more important to provide a lower temperature on thecondenserreturntemperaturetothechillerthantosavecoolingtowerfanenergy.

Inaddition,attheset‐pointof26.5°C,thecoolingtowerfanwaspracticallyrunningfullspeedatalltime.

Details An oversized cooling towerwas usedwith slightly higher power consumption tocoolthecondenserwatertocoolestpossible.

The cooling tower fan power was increased 10% from 10 kW to 11 kW in thissimulationstudytomimicanoversizedcoolingtower.



‐0.1%



ProposedLifeTime 8


RM‐5,200/coolingtowercomparedtopreviouscase

Remarks:Anassumptionwasmadetoupsizethecoolingtowerby10%.Checkhasnotbeenconductedatmarketleveltoascertainthesoundnessofthisassumption.I.e.Thenextavailablecoolingtowersizesmaybelargerthan10%.Itmayalsobepossiblethatthestandardmarketsizeavailableforcoolingtowerisalreadyoversizedforthischillerrequirement,thusnoextracostisrequiredtoupsizethecoolingtower.It is recommended to revisit this study upon checking themarket availability of the coolingtowersizes.

93

3.39CASE37:200LUXGENERALLIGHTING,19WTASKLIGHTGeneralDescriptions

In recent years, there has been a gaining market acceptance to reduce generallightingluxlevelinofficesdownto150luxlevelandthensupplementlightingneedofbuildingoccupantwithpersonal task light toprovideup to800 lux levelwhenrequired. This option allows each individual in the building to control their ownlightingpreferenceattheirowndesk.

Casestudy37to39testtheoptionofusingtasklightsinBlockFwhilereducingthegeneral lighting lux level down to 200 lux level. Reducing lux level in a buildingwouldmeanthatitispossibletoreducethenumberoflampsinthebuildinguntilitachievesaluxlevelof200lux.

Ingeneraltasklightcomesin19,11or5Wpertasklight.

Details Allowing the general lighting level to be reduced from 350 lux level (existingbuilding scenario) at 9W/m² lighting power density to 200 lux level, allows thegeneral lighting power density to be reduced to 5.1 W/m² via a process of de‐lampingor redesigning the lighting layout entirelyby removingunnecessary lightfittingsforanaverage200luxlevelofficebuilding.

Then a task light of 19Wperperson is added to the simulation. 80%of the tasklights are assumed to be switched on. 20% is assumed to be switched off due toreasonsthatbuildingoccupantsmaynotbeintheofficeorisusingthecomputersandtherefore,donotneedmorethan200 lux level.Forabuildingoccupantnoof1,000people,80%of19Woflightingperpersonworksouttoonly0.43W/m²oftheofficespace.

Theaverageoffice lightingpoweruseisnowreducedto5.57W/m²insteadofthe5.88W/m²asinpreviouscases.



4.1%



ProposedLifeTime 5


RM270/person1,000buildingoccupant

Remarks:Since 1958 the Illuminating Engineering Society (IES) has published illuminancerecommendations in table form. These tables cover both generic tasks (reading,writing etc),and100'sofveryspecifictasksandactivities(suchasdrafting,parking,milkingcows,blowingglassandbakingbread).Therecommendedminimumluxlevelonadeskinanofficespace(IlluminationCategoryC)forfrequent(&easy)readingorwritingofhighcontrast&largesize(e.g.typewrittenpage)is200lux. Thereafter, a multiplication factor can be applied based on the person age and surfacereflectanceoftheroom.RefertotheTable2andTable2aonthenextpage.

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===================================================================== TABLE 2 ===================================================================== TASK CATEGORIES AND REFERENCE ILLUMINANCE LEVELS ILLUMINANCE DIFFICULTY OF IMPORTANCE OF CATEGORY VISUAL TASK SPEED & ACCURACY non critical / critical ---------------------------------------------------------------------- A MOVEMENT THROUGH PUBLIC SPACES 50 - LUX - 75 (5) - FC - (7) ---------------------------------------------------------------------- B INFREQUENT READING OR WRITING; 100 150 High contrast & large size (9) (14) ---------------------------------------------------------------------- C FREQUENT (& easy) READING OR WRITING; 200 300 High contrast & large size (19) (28) (e.g. typewritten page) ---------------------------------------------------------------------- D MODERATELY DIFFICULT READING OR WRITING; 300 450 low contrast or small size (28) (42) (e.g. penciled mechanical drawings) ---------------------------------------------------------------------- E DIFFICULT READING OR WRITING; 500 750 low contrast & small size (46) (70) (e.g. poor copy of a blueprint) ---------------------------------------------------------------------- ===================================================================== TABLE 2a ===================================================================== ADJUSTMENTS TO REFERENCE ILLUMINANCES (for different task background reflectences and worker ages) AGE (A, in years) > 30 30-40 40-50 50-60 60+ ---------------------------------------------------------------------- TASK R > 0.8 | 1.0 1.2 1.5 2.0 3.1 BACKGROUND 0.8 - 0.6 | 1.2 1.5 1.9 2.6 3.9 REFLECTANCE 0.6 - 0.4 | 1.7 2.0 2.5 3.4 5.2 (R) 0.4 - 0.2 | 2.5 3.0 3.8 5.1 7.8 0.2 or less | 5.0 6.0 7.6 10.2 15.6 ---------------------------------------------------------------------- The proposed strategy for Case 37 to 39, is to reduce the general lighting level down to theminimum level of 200 lux and supplement with a task light that would allow the buildingoccupants themselves to choose their own preference of lighting level on their own desk,allowingbuildingoccupantstolightuptheirdeskupto800~1,000luxwhentheyneedto.ItisactuallystillwithintheIESrecommendedilluminancetoprovideaslowas100‐150luxforgenerallighting,whileatalldesks,atasklightisprovidedforilluminanceupto1,000luxwhenrequired. General office spaces (not at the desk), would be considered Category B space forinfrequent reading orwriting spaces, such as accessway between desks. Infrequent readingmay be made by building occupants while walking or standing on the access way betweendesks.

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Reducingluxleveldownto200luxilluminanceinMalaysiamaybeuncomfortabletothosethatareusedtohaving500luxormoreilluminanceofgeneral lighting.A fewstudieshaveshownthatitmaybemoreimportanttohaveabrighterceilingandwallsthantheactualluxlevelonthedesk.ThismaybedonebyusingT5pendentlightfittingsthatlightuptheceilingaswellasthe desk and supplement the wall with wall lights to ease the occupants initial discomfortfeelings.

19W 11W 5W

RM Budget 273 300 320

0

200

400

RM

RM Budget Available

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ReadCase37.


Then a task light of 11Wperperson is added to the simulation. 80%of the tasklights are assumed to be switched on. 20% is assumed to be switched off due toreasonsthatbuildingoccupantsmaynotbeintheofficeorisusingthecomputersandtherefore,donotneedmorethan200 lux level.Forabuildingoccupantnoof1,000people,80%of11Woflightingperpersonworksouttoonly0.43W/m²oftheofficespace.

Theaverageofficelightingpowerreducesto5.57W/m².



0.4%



ProposedLifeTime 5


AdditionalRM30/person

Remarks:ReadCase37.

19W 11W 5W

RM Budget 273 300 320

0

200

400

RM

RM Budget Available

97


ReadCase37.


Thenatasklightof5Wperpersonisaddedtothesimulation.80%ofthetasklightsareassumedtobeswitchedon.20%isassumedtobeswitchedoffduetoreasonsthat building occupants may not be in the office or is using the computers andtherefore,donotneedmorethan200luxlevel.Forabuildingoccupantnoof1,000people,80%of5Woflightingperpersonworksouttoonly0.19W/m²oftheofficespace.

Theaverageofficelightingpowerusereducesto5.34W/m².



0.3%



ProposedLifeTime 5


AdditionalRM20/person

Remarks:ReadCase37.

19W 11W 5W

RM Budget 273 300 320

0

200

400

RM

RM Budget Available

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3.42CASE40:DAYLIGHTSENSORFORTOILETSGeneralDescriptions

ThetoiletsinBlockFhavenaturaldaylightbecauseallthetoiletshaveafaçadewallwithexternalwindows.Itisnormallybrightduringworkinghours.However,sincethebuildingisoccupiedfrom7amonwards,thetoiletlightswouldbeswitchedonduringthosehoursbecausetheoutdoorlightisstilllowat7am.Afterthelightsareswitchedonearly in themorning, itwouldnormally remainon for therestof thedaybecausenooneisdirectlyresponsibleforsuchpublicspacessuchasthetoilets.

Theuseof daylight sensorwill automatically switchoff the lightswhen it detectsthatthereisadequatelightsinthetoilet.

Details Assumption ismade in this case that 75%of the toilet lights can be switched offwheneveradequatedaylightisavailable.

25%ofthelightsareassumednottobelinkedtothedaylightsensorbecauseitmaybeusedbythecubiclesthatmaynotbenefitfromdaylight.



0.1%



ProposedLifeTime 5


RM170/toilet

Remarks:Theuseofdaylight sensor for the toiletmaynegate theuseofoccupancysensor in the toiletbecausethelightswouldnormallybeoffduetothedaylightavailable.Itisrecommendedtousedaylight sensor only as itwould be less intrusive than amotion sensor thatmay sometimesswitchoffthelightseventhetoiletisoccupied.It isalsorecommendedtoinstallpersonalcubiclelightsincaseswherecubiclesareverydarkwhenthegenerallightingintoiletsareswitchedoffduetotheavailabilityofdaylight.

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3.43CASE41:IMPROVEDAIR‐TIGHTNESS&ADDHEATRECOVERYWHEELGeneralDescriptions

If thebuilding is retrofitted tobeair‐tight,withan infiltration rateof0.1ach (airchange per hour), itwould then be possible to consider the use of heat recoverywheel to pre‐cool and pre‐dry the fresh air intake into the building with theexhaustedairfromthebuilding.

Theheat recoverywheel reducesenergyconsumption inbuildingbyreducing thecoolingthat isrequiredofthefreshairintakebyusingthefreeexhaustairtopre‐coolandpre‐dryitbeforeitreachtheAHU.

Details Two heat recoverywheelswith an efficiency of 50% for both sensible and latentheatexchangeweremodeledforthiscase.OneheatrecoverywheelisusedforeachstackofAHUinBlockF.

Inaddition,700Wofpowerconsumptionofeachof theheatrecoverywheelwasalsomodeled.Thispowerconsumptionisrequiredtorotatethewheel.

A pair of fan was also modeled for each the heat recovery wheel. A fan totalefficiencyof50%andatotalpressurelossof200Pawereallocatedforeachfantocompute the power requirement based on the flow rate supplied. These fansprovides the pressurized fresh air intake for all the AHU and also provides thenegativepressuretoexhaustairfromthetoilets.



1.5%



ProposedLifeTime 10


RM102,040perAHUStack2AHUStackinBuilding

Remarks:TheuseofheatrecoverywheelwouldrequiresapairoffreshairductandexhaustairducttobeinstalledforeachstackofAHUinblockF.ItmayormaynotbepossibletouseexistingavailablespacesintheAHUroomtoinstallthisduct.IfspaceisnotadequatewithintheAHUroom,these

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ducts can be installed outside the building, locating it exactly where the fresh air intake isbroughtintothebuilding.Theexhaustairductcanbeplacedattheexistingexhaustfanlocationofeachtoilet.Careshouldbetakenthatthevolumeofairpassingthroughthetoiletisnottoohighthat it causesdiscomfortdraftsensation. It isalso important to insulate theduct locatedoutsidethebuildingtominimizetheheatgainfromtheexposuretotheoutdoorenvironment.

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3.44CASE42:CHANGEGLAZINGTOSINGLEGLAZING‐CLEARGeneralDescriptions

The existing single glazing in block F has a measured VLT (visible lighttransmission)ofapproximately10%.ForaheavilytintedsingleglazingwithaVLTofonly10%,atypicalSC(shadingcoefficient)isapproximately0.43.ThelowertheSCvalue,thelessheatistransmittedintothebuilding.Forasingleglazing,withoutlow‐emissivityproperties,theSCvalueof0.43isaslowasitcanget.

Unfortunately, this glazing allows too little light for any effective use of daylightharvestinginthisbuilding.

The above arepictures taken fromBlockF, providing an indicationof theheavilytinted glazing and blind usage. Note that, even with such low VLT values on theglazing,windowblindisstillrequiredtobeusedtopreventglareintheoffices.

Details TheglazingSCvaluewaschangedfrom0.43to0.95foraclearglazing.



‐0.7%



ProposedLifeTime 10


RM‐40/glazingarea

Remarks:Changing thebuildingdark tintedglazing toaclearsingleglazing, theenergyconsumptionofthebuildingincreases0.7%.However, this change would allow the building occupants to benefit from having access todaylight. The health and productivity benefit of having daylight in office building have beendocumented in several studies of green buildings worldwide. Although this option increasesenergyconsumptionofthebuilding,thehealthandproductivitygainbybuildingoccupantsfaroutweighthecostofenergy.Moreover, in the next two (2) case studies (Case 43 & 44), daylight are harvested, i.e. theelectricallightsareturnedoffwhenadequatedaylightisavailable,theenergysavinggainedishigherthanthiscase.Thisisbecausedaylightisactuallycoolerthanelectricallightinganditisalsoafreesourceofenergy.

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It is also recommended to consider the use of low‐e single glazing when this option isconsidered for the building. The additional cost for a low‐e single glazing is onlymarginallyhigherthanatypicaltintedsingleglazing.Theenergysavedfromtheuseoflow‐esingleglazingwouldbesimilartoCase45,theuseoffilmonclearglazing.

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3.45CASE43:DAYLIGHT3.5MDEPTHFROMFACADEGeneralDescriptions

Changingtheglazingtoclearwouldallowdaylighttobeharvested.Energyefficiencyisgainedwhendaylightisharvestedandelectricallightsareswitchedoff.

To ensure that electrical lights are switched off when daylight is available, it isrecommendedtousedaylightsensor.Adaylightsensorcanbeprogramedtoswitchelectricallightingsoffwheneverdaylightisadequatetolitupthespace.

Details Daylightstudiesshowedthatispossibletoharvestdaylightupto3.5mdepthfromthefaçadeusingsimplehorizontalvenetianblindonthewindows.Thesehorizontalblindswouldallowglaretobecontrolledbytiltingittoa levelwherethebuildingoccupant view of the sky is reduced until visual comfort is achieved. Light areallowedtobounceofftheblindsintotheroom.Thiswouldrequirethelouvers(ofthe blind) to be reflective white or mirror like finish on the top side and non‐reflectivewhitepaintonthebottomsideofthelouversforglareprevention.

Adepthof3.5mdaylightharvestinginthisbuildingwouldcoverapproximately40%of the office floor area. An assumption ismade in the simulation that 40%of theoffice lightings are switched off when outdoor horizontal illumination is above10,000luxlevel.



2.3%



ProposedLifeTime 10


RM120/m²ofglazingarea

Remarks:ThesimulationstudyshowsthatusingverticalblindasitisbeingusednowintheBlockF,willnotallowdaylighttobeharvestedwithoutcausingglaretothebuildingoccupant.

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It is very important to emphasis thatdaylightharvestingwill onlywork in this climatewhenglarecomfort is addressed. It isproposed touse simplehorizontalvenetianblinds toharvestdaylightinBlockF.Theseblindsshouldbetiltedfromhorizontal(fullyopenposition)untilthebuildingoccupantisvisuallycomfortablefromtheirusualsittingposition.Normallythiswouldbebetween20~35°fromhorizontal.Thelowerthetilt,themoredaylightthatcanbeharvesteddeeperintothespace,allowingmorelightstobeswitchedoffwhendaylightisavailable.TheavailablebudgetofRM120/m²ofglazingarea,shouldbeenoughtopayforthehorizontalblindsrequiredtobenefitfromthisefficiencygain.

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3.46CASE44:DAYLIGHT4.5MDEPTHFROMFACADEGeneralDescriptions

Theinstallationoflightalightshelveontheparapetwalllevelontheoutsidewouldallowmore light to be captured for thebuilding. In addition, by tilting the ceilingsurface near the façade allows the capture light to direct it deeper into the officespaceasshowninthediagrambelow.

Simulationstudyshowedthatitispossibletoharnessdaylightanothermeterdeepfromthefaçade,makingthedaylightharvestedleveltobe4.5mdepth.

Details Adepthof4.5mdaylightharvestinginthisbuildingwouldcoverapproximately55%of the office floor area. An assumption ismade in the simulation that 55%of theoffice lightings are switched off when outdoor horizontal illumination is above10,000luxlevel.

LightshelvewasmodeledinRadiancetotestthedepthofdaylightharvested.



0.6%



ProposedLifeTime 10



Remarks:Thelightshelveusedinthissimulationstudyimprovedthedepthofdaylightby1m.Howeveranadditional1mdepthofdaylightonlyincreasesthefloorareacoveredbydaylightfrom40%to55%,anincrementof15%onlyasopposedtothe1stdaylightoptionof40%floorarea.Therefore,theenergysavingprovidedisonlymarginallybetter,providinganavailablebudgetofRM30/m²ofglazingareaonly.Thisbudgetwouldnotbeadequate toprovideanexternallightshelvesthatcanwithstandtheoutdoorenvironment,sun,rainandwind.

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3.47CASE45:PERFORMANCEFILMONGLAZINGGeneralDescriptions

Performance film is frequently installed in car glazing by car owners inMalaysia.Someofthemorefamousfilmsavailable inMalaysiaareV‐Kool,3MPrestigeFilm,HuperOptikandetc.

Acheckonthetechnicaldataof3MPrestigeFilmshownbelow,itispossibletogetfilminstalledonaclearglazingtoprovideaVLTof50%andSCof0.51.

Details TheglazingpropertieswaschangedtoaSCof0.51andaninsideemissivityof0.78as provided by the specification of 3M Prestige 50 film. This selectionwasmadebecausethedaylightharvestingrequirementfromthesimulationstudyshowedthataminimumVLTof~50%isrequiredtomaintaindepthofdaylightharvested.



0.6%



ProposedLifeTime 10



Remarks:Thereisanenergysavingof0.6%bytheimplementationofthesehighperformancefilms.However,energysavingofRM32/m²ofglazingareapredicted isnotadequate topay for thefilmsbecausethecostofthesefilmsrangefromRM15to30/ft².Therefore,theavailablebudgetisapproximately10timestoolittletopayforthefilms.Itisherebyrecommendedtolookintotheoptionofusingsingleglazinglow‐eglassinsteadofconsideringtheimplementationoffilmonglazingforBlockF.

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3.48CASE46:CHANGETOPERFORMANCEDOUBLEGLAZINGGeneralDescriptions

Highperformancedoubleglazinghasabetterperformanceintermsoflighttosolarheatgainratiothanperformancewindowfilms.Whileallowingthesameamountoflight to pass through the glazing, the highperformancedouble glazing (spectrallyselective)hasalowerSC(shadingcoefficient).

A typical high performance double glazing shown below displayed a “ColouredIndigo48T”doubleglazingwithaVLTof48%andaSCof0.33.

Details TheglazingpropertywaschangedtoaSCof0.33asprovidedbythespecificationshownabove.Thisselectionwasmadebecausethedaylightharvestingrequirementfrom the simulation study showed that a minimum VLT of ~50% is required tomaintaindepthofdaylightharvested.



0.6%



ProposedLifeTime 10



Remarks:Convertingtoahighperformancedoubleglazingforanexistingbuildingisalsoshowntobenoteconomicallyfeasible.TheavailablebudgetofRM64/m²(convertingfromsingleclearglazingdirectly to double glazing, skipping the use of film on glazing) of glazing areawould not beadequateforahighperformancedoubleglazing.

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3.49CASE47:ROOFINSULATION,50MMPOLYSTYRENEGeneralDescriptions

The un‐insulated flat roof is insulated with 50mm polystyrene foam. This willreduce theU‐valueof the roof from3.44 to0.51W/m²K. Insulating the roofwillreduce energy consumption of the building by reduction of heat gain through theroofduringdaytime.

Details BaseCaseFlatRoof–NoinsulationFromToptoBottomLayerNo MaterialsDescriptions Thickness(mm)1 StoneChippings 102 WaterProofingMembrane 53 DenseConcreteSlab 150 TotalThickness ~165

AshraeU‐value:3.44W/m²K

Case47–50mminsulatedFlatRoofFromToptoBottomLayerNo MaterialsDescriptions Thickness(mm)1 StoneChippings 102 WaterProofingMembrane 53 PolystyreneFoam 504 DenseConcreteSlab 150 TotalThickness ~215




0.2%



ProposedLifeTime 10


RM17/m²roofarea

Remarks:Reducing the roof U‐value down to 0.51 W/m²K provided adequate budget for the use ofinsulationontheroof.Typicalcostof50mminsulationpolystyrenefoamrangefromRM15to30/m²dependingonthebrand.

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The flat roof is insulated with 100mm polystyrene foam. This will reduce the U‐value of the roof to 0.28 W/m²K. Insulating the roof will reduce energyconsumption of the building by reduction of heat gain through the roof duringdaytime.

Details Case48–100mminsulatedFlatRoofFromToptoBottomLayerNo MaterialsDescriptions Thickness(mm)1 StoneChippings 102 WaterProofingMembrane 53 PolystyreneFoam 1004 DenseConcreteSlab 150 TotalThickness ~265




0.2%



ProposedLifeTime 10


RM15/m²roofarea

Remarks:ReducingtheroofU‐valuedownto0.28W/m²KprovidedabudgetofRM32/m²,fromhavingnoinsulationdirectlytohaving100mmroofinsulation.

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The flat roof is insulated with 100mm polystyrene foam. This will reduce the U‐value of the roof to 0.19 W/m²K. Insulating the roof will reduce energyconsumption of the building by reduction of heat gain through the roof duringdaytime.

Details Case49–150mminsulatedFlatRoofFromToptoBottomLayerNo MaterialsDescriptions Thickness(mm)1 StoneChippings 102 WaterProofingMembrane 53 PolystyreneFoam 1504 DenseConcreteSlab 150 TotalThickness ~315




‐0.2%



ProposedLifeTime 10


RM‐10/roofarea

Remarks:Increasingtheroofinsulationto150mmthick(reducingU‐valuedownto0.19W/m²K),actuallyprovidedhigherenergyconsumptionthantheuseof100mmthickinsulationontheroof.The roof needs to prevent heat gain during daytime and insulation on the roof would bebeneficial.Howeverduringnighttime,theskytemperaturerangefrom10°Cto20°C(dependingon thecloudcover),averagingaround15°C.Heat fromtheroof is thenradiated to thecoolernightsky.Therefore,insulationtheroofisabalancebetweentheheatgainduringdaytimeandheatlostduringnighttime.Overinsulation,asisshowninthiscasepreventedtheheatfromthebuildingtoberadiatedtothenightsky.

Cases Thickness U‐Value(W/m²K)

% Savings fromPreviousstep

47 50mm 0.51 0.2%

48 100mm 0.28 0.2%

49 150mm 0.19 ‐0.2%

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3.52CASE50:AIRTEMPERATURESET‐POINT:24.5°CGeneralDescriptions

Theoperative temperature isoneof the indicatorsofcomfortasrecommended inAshrae55forthermalcomfort.Theoperativetemperatureisdefinedastheaveragetemperature between the air and the mean‐radiant (surfaces) temperature. InAshrae 55, it is recommended that it would be comfortable when the operativetemperatureisbelow25°C.

Whensurfaces temperatureswerehigherdue to theuseof singleglazingandun‐insulatedroof,theairtemperatureoftheofficespaceisrequiredtobesetto23.5°Ctoprovidecomfortcondition.Howeveruponimprovementmadeonthebuildingupto this stage, themean‐radiant (surface) temperatureof theoffice spacehasbeenreduced.Thereductionofmean‐radianttemperatureoftheofficespaceallowstheair‐temperatureofthespacetobeincreasedwhilemaintainingthesamecomforttothebuildingoccupantwhilemaintaininganoperativetemperaturebelow25°C.

Details Theroomtemperatureset‐pointwasraisedto24.5°C±1°C.



0.8%



ProposedLifeTime NA


NA

Remarks:Thesimulatedresultsshowedthatatthesetpointof24.5°C,theaverageroomtemperaturesarejustbelow24°C,whileprovidinganoperativetemperaturebelow24.5°Catalltime.

Legend:Case14–ComfortableBaseCondition.Case49–ImprovedBuilding.Case50–IncreasedAirTemperature.DryResultantTemperature=OperativeTemperature

00:00 06:00 12:00 18:00 00:00

3130292827262524232221

Tem

pera

ture

(°C

)

Date: Tue 17/Jan

Air temperature: OFFICE1_F05 (c50_otemp25.aps)

Air temperature: OFFICE1_F05 (c49_rf_in150.aps)

Air temperature: OFFICE1_F05 (c14_tsetpt_higher.aps)

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Thetwo(2)chartsaboveshowedthatalthoughtheairtemperaturewasincreasedinCase50,theoperative temperature is still thesameasCase14,where theair temperaturewas lower.ThisisbecauseinCase49&50,themeanradianttemperatureofthebuildingfabricandfromthelightshasreduced.Therefore,inCase50,withtheincreaseinairtemperature,thecomfortconditionisstillthesameasinCase14withlowerairtemperature.Energyefficiencygainisobtainedduetothehigherairtemperatureprovidedtothebuildinginthiscase.

00:00 06:00 12:00 18:00 00:00

31

30

29

28

27

26

25

24

23

22

Te

mp

era

ture

(°C

)

Date: Tue 17/Jan

Dry resultant temperature: OFFICE1_F05 (c50_otemp25.aps)

Dry resultant temperature: OFFICE1_F05 (c49_rf_in150.aps)

Dry resultant temperature: OFFICE1_F05 (c14_tsetpt_higher.aps)

Operative Temperatures

113

3.53CASE51:RESIZEHVACASPERCURRENTNEEDGeneralDescriptions

Afterimprovingthebuildinginvariousaspectsinenergyefficiencies,anattempttoresizethewatersideHVACsystemwasconductedtooptimizethesizeofthechiller,pumpsandcoolingtower.

Details Thechillwatersystemwasresizedatthecurrentscenariowherethesmallpowerpeakloadis4.1W/m².



0.3%



ProposedLifeTime NA


NA

Remarks:Right sizing the chill water system to the actual operating condition would improve energyefficiencyofthebuildingbecausethepumps,chillersandcoolingtoweraresizedjustrightforthisbuilding.However, ifthebuildinggrowsinpopulationdensity, itmaynotbeabletocaterfortheincreasedsmallpowerload.Itwas also found that the existing chiller provided for the building is inadequate to providecooling to the entire building. It is likely that when the chiller was 1st put into the building(approximately20yearsago),thesmallpowerloadofbuildingswerenotashighasitistoday,allowingchillerstobedesignedtobeofsmallercapacity.Howeversincethemid‐1990s,ithasbecomecommontohaveonepersonalcomputerforeachpersoninthebuildingasitistoday.

Sizingthepeakchillerrequirementofthebasecase(comfortablescenario),thechillercapacityshouldhavebeenapproximately1,000 toncapacity.Thishugecapacitywasrequired tocaterfor the building air‐leakages and other inefficiencies as listed in this study. However, the

114

providedchillercapacitywasonly380toninblockF.Resizingthecoolingsystemwithapeaksmallpowerloadof4.1W/m²inthebuildingmatchesthe current installed chiller capacityof380 ton. If thepeak smallpowerwas increased to12W/m²,thepeakchillercapacitywouldbe410ton.Therefore,ifenergyefficiencymeasuresarenottakeninBlockF,thenewchillertobeorderedforthebuildingwillhavetobe1,000ton,inordertoprovideadequatecomfortcoolingtothebuildingoccupants.Moreover,thechillersforblockFaremorethan20yearsoldandaredueforreplacementanytimenow.By the implementation of energy efficiency, the chiller capacity required now is 410 ton, areduction of approximately 600 ton. A typical chiller cost is approximately RM 3,500/ton, areductionof 600 ton, reduces the investment cost for thenew chillersbyRM2.1millionperchiller. For the 2 chillers as required inBlock F, thiswouldprovide a total saving of RM4.2million.Whenthisnumberisdividedbythem²ofglazingareaforthebuilding,theavailablebudgetisRM1,700/m²ofglazingarea.This isadequatebudget toreplace theentirebuilding intohighperformance double glazing and incorporating high performance façade features of daylightharvestingforthisbuilding.Itisalsopossibletousethisbudgettoupgradetheentirebuildingtobeair‐tightbyreplacingtheentireglazingunitwithair‐tightframes,provisionofhighvisiblelight transmission glazing with high quality horizontal venetian blinds, provision of heatrecoverywheelandetc.

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3.54CASE52:RESIZEHVAC@12W/M²SMALLPOWERGeneralDescriptions

ItwasfeltthatresizingtheHVACsystemwithapeaksmallpowerloadof4.1W/m²may not leave room for future expansion in the building for higher densityoccupancy.TheHVACsystemwasthenresizewithanassumptionof12W/m²asthesmallpowerpeakload.

Details The HVAC systemwas resized assuming 12W/m² of peak small power load butenergy simulationwas conducted using actualmeasured small power load of 4.1W/m².



‐0.1%



ProposedLifeTime NA


NA

Remarks:ReadCase51Remarks.

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3.55CASE53:SMALLPOWERBACKTOMEASUREDVALUEGeneralDescriptions

Incasesofamulti‐tenantedofficebuilding, itmaynotbepossibleto influencethetenant to be energy efficient with their non‐office hour’s energy consumption.Thereforeinthiscasestudy,thesmallpowerloadisreturnedbacktothemeasuredvalueof4.1W/m²duringofficehoursand1W/m²duringnon‐officehours.

Details Thesmallpower load isreturnedbackto themeasuredvalueof4.1W/m²duringofficehoursand1W/m²(25%ofthepeakload)duringnon‐officehours.Previouslyitwassetto4.1W/m²duringofficehoursand0.41W/m²(10%ofthepeakload)duringnon‐officehours.



‐2.3%



ProposedLifeTime NA


NA

Remarks:Thesmallpowerinefficiencyduringnighttimecausedanincreaseof2.3%buildingenergyuse.This figure is quite high considering that on an average; each proposed strategy in thisdocumentprovidedonly0.9%savings.However,thebuildingBEIstillremainsquitelowat84.6kWh/m²/year.Moreover,thisBEIhasnotexcludedthedatacenterfromitscomputation.It should be noted that the small powerwasmeasured in Block F togetherwith the lightingpowerastheysharethesamecircuit.Thelightingpowerwasestimatedbytheenergyauditoronafloorbyfloorbasiswithwalkthroughtocalculatethenumbersoflightfittingsandlamps.Theyalsocalculatedthenumberoflampsthatarenotoperational(faulty),andthenthelightingpower is computedbasedon theoperational lampsonly.Thesmallpower is thenderivedbydeductingthelightingpowerfromthemeasuredlightingandsmallpowercircuit.

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Sample Cut out of Appendix 4.4.2 from Energy Auditor Report Table B : Lighting Power & Energy Consumption

Level

Room No./Description

No. of lamps/ fitting

No. of fittings

Total No. of lamps

Watts (lamp+ballast)

Total Watts

No. of Faulty Lamps

Total Watt for Faulty Lamps

Actual Lighting Power (W)

17 Staircase L 2 2 4 20 80 0 0 80 17 Office R 3 4 12 40 480 0 0 480 17 Office (Director) 3 1 3 20 60 0 0 60 17 Office (Director) 3 1 3 40 120 0 0 120 17 Meeting Room 3 6 18 40 720 0 0 720 17 Meeting Room 1 12 12 26 312 0 0 312 17 Meeting Room 1 8 8 20 160 2 40 120 17 Meeting Room 1 8 8 18 144 1 18 126 17 Eng Accreditation 3 3 9 20 180 0 0 180

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3.56CASE54:SMALLPOWER@12W/M²GeneralDescriptions

ThisisjustatestscenariotopredicttheBEIofthebuildingwhenthesmallpowerisincreasedto12W/m²asitwouldbeinadenselyoccupiedbuilding.

Details Thesmallpowerwasraisedto12W/m²withabaseloadatnightandweekendof25%ofthisdaytimepeakvalue.



‐20.2%



ProposedLifeTime NA


NA

Remarks:The impactofhaving12W/m²smallpowerdensity forBlockF, increasesthebuildingBEIto117 kWh/m²/year. This BEI includes the data center energy consumption ofmore than 100MWh/year.Following theMalaysia’s GreenBuilding Index (GBI) definition of BEI,where the data centerpowerconsumptionandfloorareaisexcludedfromthecomputationofBEI,theBEIofBlockFinthiscasescenariowillbeapproximately42kWh/m²/year.Thisvalueisapproximately50%moreenergyefficient than thehighestpointsachievable forenergyefficiency inGBI,whereaBEI of less than 90 kWh/m²/year would score full points in terms of energy efficiency inbuildinginGBIratingtool.Itshouldbepointedout thatnotall featuresproposed in thisdocumentare financiallyviableoption.SomeofthefeaturessuchasVAVsystemandvariablechillwaterflowrateneednotbeimplementedasthepredictedenergyefficiencygainisminimalforBlockFwherethebuildingcoolingloadwasmeasuredtobefairlyconstantandconsistenteveryworkingday.Therefore,attheendofthedaythetargetof42kWh/m²/yearmaynotbeachievable.However,achievinganyvalue of less than 60 kWh/m²/year would havemade this building a “show‐case” where anexistingbuildingcanbemadeasenergyefficientasthosenew“demonstration”energyefficientbuildings.

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3.57CASE55:25%ENERGYREDUCTIONINDATACENTERGeneralDescriptions

Power Usage Effectiveness (PUE) and its reciprocal Data Center infrastructureEfficiency (DCiE) are widely accepted benchmarking standards proposed by theGreenGridtohelpITProfessionalsdeterminehowenergyefficientdatacentersare,andtomonitortheimpactoftheirefficiencyefforts.Benchmarkingtoolisusefulasanindicatorofdatacenterenergyefficiency.

TotalFacilityPower kWITEquipmentPower kW

ITEquipmentPower kWTotalFacilityPower kW

Today, thereexistmanydemonstrationdatacenteraroundtheworldwheremorethan50%energysavinghasbeenmade.ThiscanalsobeseenfromthePUEindexesshowingPUEvaluesfrom1.2to3.0,indicatingthatveryinefficientdatacenterusemorethandoubletheenergyascomparedtoaveryefficientdatacenter.

The use of efficient IT equipment will significantly reduce cooling requirementwithinthedatacenter,whichconsequentlywillreducetheHVACequipmentneededto cool them. Purchasing servers equippedwith energy‐efficient processors, fans,and power supplies, high‐efficient network equipment, consolidating storagedevices,consolidatingpowersupplies,andimplementingvirtualizationarethemostcommonwaystoreduceITequipmentloadswithinadatacenter.

Details An assumption that the data center annual energy consumption was reduced by25%.



6.1%



ProposedLifeTime 3


RM242,000fordatacenter

Remarks:Thiscasestudyisprovidedtocomputetheavailablebudgetforinvestinginanenergyefficient

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datacenterwherethecurrentdatacenterinBlockFreducesitsenergyconsumptionby25%.Thisenergyefficiencygain indatacentermaybeachievableby the implementationof servervirtualization.Virtualization technology is transforming today’s IT community, offering new possibilities toimprove theperformanceandefficiencyof IT infrastructurebyadynamicmappingof thePCresources, enabling to run multiple applications and operating systems on a single physicalsystem.

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3.58CASE56:50%ENERGYREDUCTIONINDATACENTERGeneralDescriptions

Today, thereexistmanydemonstrationdatacenteraroundtheworldwheremorethan50%energysavinghasbeenmade.

The use of efficient IT equipment will significantly reduce cooling requirementwithinthedatacenter,whichconsequentlywillreducetheHVACequipmentneededto cool them. Purchasing servers equippedwith energy‐efficient processors, fans,and power supplies, high‐efficient network equipment, consolidating storagedevices,consolidatingpowersupplies,andimplementingvirtualizationarethemostcommonwaystoreduceITequipmentloadswithinadatacenter.

Details An assumption that the data center annual energy consumption was reduced by50%.



6.1%



ProposedLifeTime 3


RM242,000fordatacenter

Remarks:Thiscasestudyisprovidedtocomputetheavailablebudgetforinvestinginanenergyefficientdata center where the current data center in Block F reduces its energy consumption by anadditional 25%. This energy efficiency gain in data center may be achievable by theimplementationofenergyefficientcoolingsystemfordatacenter.Newcoolingtechnologyfordatacenterhasbeenhelpingtoreducepowerconsumptionindatacenter.Afewapplicabletechnologiesfordatacenterareasdescribedbelow:

1. New variable speed drive (VSD) precision cooling unit are being produced for datacenter.

2. Hot/coldaislecontainmentstrategy.3. Liquidcooling.4. DataCentertemperaturesetpointupto27°Cforclass1&2equipment.5. Lowpressuredropairdelivery.6. Etc.

There are many guideline published for energy efficiency in data center these days. It isrecommended that those that are interested in energy efficiency for data center to look upthese guidelines for design details to reduce energy consumption in data center by 50% ormore.

Documents

DETAILED TECHNICAL REPORT POTENTIAL OF ENERGY EFFICIENCY IN EXISTING … · 2018-10-04 · buildings and by improving the energy utilization efficiency in the operation of existing