Table Of Content

5.1 Energy Auditing Amine AllouhiandAli Boharb,Sidi Mohamed BenAbdellah University,Fez, Morocco RahmanSaidur, Sunway University, Selangor,Malaysia andLancaster University,Lancaster, United Kingdom Tarik Kousksou, University ofPau andPaysdel'Adour, Pau, France Abdelmajid Jamil, SidiMohamed BenAbdellah University, Fez,Morocco r2018ElsevierInc.Allrightsreserved. 5.1.1 Introduction 3 5.1.2 Fundamentals of EnergyAudit 3 5.1.2.1 Definition 3 5.1.2.2 Classification ofEnergy Audits 3 5.1.2.2.1 Industrial energy audits 3 5.1.2.2.2 Commercial energy audits 4 5.1.2.2.3 Residential energy audits 4 5.1.2.3 EnergyAudit Levels 4 5.1.2.3.1 ASHRAELevel 1 –walk-through analysis/preliminary audit 5 5.1.2.3.2 ASHRAELevel 2 –energy survey andanalysis 5 5.1.2.3.3 ASHRAELevel 3 –detailed analysis ofcapital intensivemodifications 5 5.1.2.4 EnergyAudit:General Procedure 5 5.1.2.4.1 Preparation phase 6 5.1.2.4.2 Executionphase 6 5.1.2.4.3 Reportingphase 7 5.1.2.4.4 Postaudit phase 7 5.1.3 Instrumentation for EnergyAuditing 7 5.1.3.1 Measuring Electrical Parameters 7 5.1.3.1.1 Electric energy meters 7 5.1.3.1.2 Electrical network analyzers 8 5.1.3.2 Internal ComfortMeasurements 9 5.1.3.2.1 Thermometers 9 5.1.3.2.2 Infrared thermometers 10 5.1.3.2.3 Anemometers 10 5.1.3.2.4 Humidity measurements 10 5.1.3.2.5 Carbondioxide meter 11 5.1.3.2.6 Lighting level measurements 11 5.1.3.2.7 Heatflux meter 12 5.1.3.2.8 Blower door test 13 5.1.3.3 OtherMeasurements 14 5.1.3.3.1 Combustion analyzers 14 5.1.3.3.2 Speedmeasurements 14 5.1.3.3.3 Leak detectors 15 5.1.3.3.4 Flow meters 15 5.1.4 EnergyEfficiencyMeasures 16 5.1.4.1 Building Envelope 16 5.1.4.1.1 Thermal insulation 16 5.1.4.1.2 Windows 18 5.1.4.1.3 External shading 18 5.1.4.1.4 Reduction ofair infiltration 18 5.1.4.2 Heating, Ventilating,andAir-Conditioning Systems 19 5.1.4.3 Electrical Systems 20 5.1.4.3.1 Transformers 20 5.1.4.3.2 Quality ofelectrical energy 21 5.1.4.3.3 Electrical motors 22 5.1.4.3.4 Lighting systems 22 5.1.4.4 Compressed-Air Installation 24 5.1.4.5 Combustion Installations 25 5.1.5 CaseStudy: Energy Auditing 25 5.1.5.1 Introduction 25 ComprehensiveEnergySystems,Volume5 doi:10.1016/B978-0-12-809597-3.00503-4 1 2 EnergyAuditing 5.1.5.2 Methodology 26 5.1.5.2.1 Manufacturing process 26 5.1.5.2.2 Auditprocess 27 5.1.5.2.3 Datacollection andmeasurements 27 5.1.5.2.4 Mathematical formulations 27 5.1.5.3 Analysis 28 5.1.5.3.1 Profileof monthly electricity use 28 5.1.5.3.1.1 Monthly electricity price 28 5.1.5.3.1.2 Subscribed power 28 5.1.5.3.2 Transformers 30 5.1.5.3.2.1 Energy lossesin transformers 30 5.1.5.3.2.2 Analysis ofenergy quality intransformers 31 5.1.5.3.3 Energy-intensive motors 31 5.1.5.3.3.1 Motors withoutvariable frequency drive 31 5.1.5.3.3.2 Motors equipped with variablefrequency drive 33 5.1.5.3.4 Compressed-air installations 33 5.1.5.4 Actions Plan andAnalysis 35 5.1.5.4.1 Action1: revise thesubscribed powers 35 5.1.5.4.2 Action2: adopt high-efficiency transformers 35 5.1.5.4.3 Action3: improving energyefficiencyof electric motors 38 5.1.5.4.4 Action4: install variable frequencydrive atlow-load motors 40 5.1.5.4.5 Action5: installation of variable frequencydrive atthe compressed air compressor 40 5.1.5.4.6 Action6: treatmentof harmonic pollution 40 5.1.5.5 Conclusions 43 5.1.6 Closing Remarks 43 References 43 RelevantWebsites 44 Nomenclature I Increaseduetoadisplacementpowerfactor DPF AEP Averageelectricityprice(excludingtaxes), below0.8,MAD MAD/kWh PB Paybackperiod,years AES Annualenergysaving,MWh/year PC Powercost,MAD APmax Monthlymaximalactivepower,MW PSP Priceofsubscribedpower,MAD/kW CF Consumptionfee,MAD r Reductivecoefficient EC Energyconsumed,MWh SP Subscribedpower,MVA E Efficiencyratingofenergy-efficientmotor,% TEC Totalenergyconsumption,MWh ee EP Electricitypricesforthetimeslicex,MAD/kWh THDI Totalharmoniccurrentdistortion,% x E Standardmotorefficiencyrating,% THDV Totalharmonicvoltagedistortion,% srd FEPC Feeoftheexcessofsubscribedpower,MAD V Volumeofthespacetobeheated,m3 Greekletters l Thermalconductivity,W/mK Z Efficiency r c Volumetricheatcapacity,Wh/m3K a a Z Averageseasonalefficiencyoftheheat REC recoveryunit Abbreviations LED Light-emittingdiode C Compressor MAD Moroccandirham CO Carbonmonoxide Mot Motor CO Carbondioxide Mot-VFD MotorwithVFD 2 SC Specificconsumption MV Mediumvoltage DPF Displacementpowerfactor RMS Rootmeansquare h Hours Tr Transformer HV Highvoltage VFD Variablefrequencydrive HVAC Heating,ventilationandairconditioning EnergyAuditing 3 5.1.1 Introduction Energyisusedintheindustrial,commercial,andresidentialsectorsbyvariousequipment,machineries,andprocesses.Worldwide, more than half of the total energy goes to the industrial sector for different industrial purposes. Other sectors also use a quite sizeable amount of energy for various purposes. However, sometimes energy is not used in the most efficient manner for the above-mentioned sectors. A huge amount of energy is lost or wasted, while used in many pieces of equipment and processes. Environmentalconcerninrelationwiththeuseoffossilbasedenergyisanothermajorglobalissuethatneedstobeconsidered seriously.Insuchasituation,energyauditisanapproachthatidentifieslosses,amountofenergyusedbyvariousequipmentand processes, where energy goes, major energy-using equipment, breakdown of energy consumption, and opportunities for improvement. This is fundamental information needed for energy efficiency improvement, policy development, energy cost analysis forcompanybenefit/profit,identificationofenergyconservation measures,andmitigation techniquestoreducegreen- housegasemissions. Itwasreportedintheliterature[1]thatawell-definedenergyefficiencyimprovementstrategymayreduceenergyconsumption by70%forindustrialprocessenergyuse. Comprehensive information for details of energy audit on energy efficiency improvement, policy development, and envir- onmentalanalysisisneededformanydevelopingcountries,especiallythosewithlimitedenergyresources.Therefore,thischapter willservethepurposeoffillingthesegapsuptoacertainextent. Energyauditsvarydependingonmanyfactors,suchasthestructuretypeandsize,scopeanddepthoftheanalysisandtypeof applicationsinvolved.Residential, commercial,andindustrialenergyauditsatdifferentlevelsofanalysisareincreasingly being conductedinseveralcountriesworldwide.Thepatternofenergyuseforeachcategorydesignatesthetypeandamountofenergy losses. While insulation issues, heating, ventilation, and air conditioning (HVAC) applications and lighting present the main energyconservationopportunitiesintheresidentialandcommercialsectors,theopportunitiesaremorerelatedtootherspecific applicationsintheindustrialsector.Variouslosses(i.e.,ironlossesandcopperlosses)takeplaceinthetransformer(Tr).Energyis lostduetooperatingconditions,suchashighaltitude,extremetemperaturefluctuations,accentuatedhumidity,seismicactivity, severecontamination,andunexpectedvoltagevariations.Theseconditionscauseevenandoddharmonicandintermittentloading [2].Sometimeselectricmotors(Mots)areoversizedandthismakestheminefficient.Consequently,thisleadstohugewastageof electrical energy [3]. There are various losses taking place in Mots as well. Since electric Mots have diverse applications and consume a major share of total energy consumption (TEC), their efficiency improvement will be of great importance from the economicandenvironmentalpointofview.Therearevarioustechnologiesavailabletodiminishenergyconsumptionofelectric Mots.Variablespeeddriveisoneofthetechnologiesthatcanadjustthespeedrequired.Thisconsequentlyreducesahugeamount ofenergyconsumption[4,5]. About 10–30% of total energy is used by compressed air systems and it was reported that this form of energy is the least efficient since only 30% of it is useful and the remaining percentage is lost as heat, through leakage and inefficient usage [6]. EnergyislostinHVAC,lighting,combustionprocess,andotherelectricsystems,aswell.Therefore,anenergyauditisnecessaryto identifyvariouslossestoimprovetheefficiencyofenergy-usingequipment,machinery,andprocesses. 5.1.2 Fundamentals of Energy Audit 5.1.2.1 Definition An energy audit can be defined as an inspection or survey analysis of energy flows in a structure, in a process or in a system, intendedtoreducetheamountofenergyinputwithoutnegativelyaffectingtheoutputs[7].Itistheprimaryphaseinproposing possibilities to diminish energy expense and carbon footprints and therefore, is a key point in decision-making in the area of energymanagement.Foranorganization,energyaudithelpstounderstand,quantify,andanalyzeitsenergyutilization.Itpermits todetectwherewastetakesplace,identifythemostcriticalpointsanddiscoveropportunitieswhereenergyconsumptioncanbe reduced.Finally,bymeansofeco-efficientandfeasiblepracticesandenergyconservationmethods,overallenergyefficiencyofthe organizationwillbeimprovedanditsenergybillwillbereduced[8]. Thisactivityhasdifferentnamesindifferentcountries.InEuropethetermenergyauditisoftenused.IntheUnitedStates,energy assessmentsarethemostpracticallyemployedandinsomecasesthetermenergysurveyorenergyscancanbeencountered. 5.1.2.2 Classification of EnergyAudits 5.1.2.2.1 Industrial energy audits Industrialenergyauditsareconsideredamongthemostcomplexandlargeauditsduetothegreatvarietyofequipmentfoundin industries.Generally,thereisanimportantsimilaritybetweenindustrialequipmentandthosefoundduringcommercialaudits, suchasair-conditioners,ventilatingfans,waterheaters,coolersandfreezers,andlightingsystems,whicharegenerallyusedinboth commercialandindustrialorganizations.Whatmakesthedifferenceinindustrialfacilitiesisthespecializedequipmentused.The mostimportanttaskhereistounderstandhowthisspecializedequipmentworks,whataretheconditionsaffectingitsoperation andparticularlyhowtomakesignificantimprovementstoreduceitsenergyconsumption. 4 EnergyAuditing Forthis,datasourcesrelatedtospecializedequipmentshouldbemaintainedinalibraryofinformationandtheauditteam musthaveaccesstoadditionalinformationsourcesthataregenerallyavailableatresearchorganizationsandequipmentsuppliers. Currently,someelectricandgasutilitieswithsufficientlytrainedandexperiencedstaffofferindustrialauditstotheircustomers. Practical changes, including sometimes new equipment acquisition are therefore proposed to minimize the energy costs for a particularproductionenvironment.Insomecountries,insteadofofferingenergyauditstotheirconsumers,theyprogramfinancial incentivestoinstallhighefficiencylighting,Mots,boilers,andotherequipment.IntheUnitedStates,forexample,theInformation CenterofEnergyEfficiency&RenewableEnergyattheDepartmentOfEnergy(DOE)providestechnicalassistanceandguidanceto allsizesofplantsandcustomizedenergyefficiencyconsultationtosmallandmedium-sizedindustriesfreeofcharge. Energy audits in industries are also unique because of the structure of energy billing that generally belongs to the large commercialorindustrialratecategorywithaninterruptibleratethatgivesmuchcheaperenergyservice. Inthe industrial sector, while conducting an energyaudit,safety remains a paramount concern. Compared toresidential or commercial energy audits, many risks resulting from contact with hot objects, electric shocks, hazardous materials, falling frag- ments, and drive belts need to be avoided. Therefore, personal protective equipment (PPE) including safety glasses and shoes, specializedgloves,hardhats,andreflectiveJacketsarehighlyrequiredinsuchaudits. 5.1.2.2.2 Commercial energy audits Commercialenergyauditsdifferlargelyfromsimpleauditsforsmallofficestoverycomplexauditsformultistoryofficebuildings orgiantbusinesscenters[9].Asstatedbefore,therearemanysimilaritiesbetweenlargecommercialandindustrialaudits.Instead of focusing on the highly specialized equipment used in the production process of facilities, the most important point in commercial structures is the building envelope that should be carefully examined. Many envelope features, such as building materials,insulationproducts,windows,exteriordoors,andskylightdesignandair-sealingcanberegardedaspotentialoppor- tunitiesforimprovingenergyefficiency. Moreover,commercialfacilitiesarecharacterizedbyexcessiveuseofelectricalenergyandhavethelargercapacityequipment, such as air-conditioners, water heaters, cookers, refrigerators, and office equipment (computers, copy machines, and phones). Therefore, adoption of more efficient equipment and reuse of waste heat can also be identified as potential opportunities for reducingenergyconsumption. Animportantdifferencebetweenindustrialandcommercialauditsreliesonthelightingapplication.Lightingincommercial structuresisanenergy-intensiveusageandaccountsfor50%ormoreofthetotalelectricbill.Lightingqualityandlevelsarevery crucialinvariouscommercialoperations.Theimprovementmustfocusonsuggestingnewlightingoptionsthatpermithighlight levels,whilereducingthewattageneeded. Inmanycountriesworldwide,commercialbuildingsarebilledforenergybasedontheirsize.Inthissense,smallcommercial customers pay on the basis of a per energy unit, while large commercial customers pay according to a more complex billing structureinvolvingvariouselements,suchasenergy,rateofenergyuse,powerfactor,timeofday,seasonofyear,powerfactor,and otherelements. 5.1.2.2.3 Residential energy audits Therearemanysimilaritiesbetweenenergyauditsforlarge,multistoryapartmentbuildingsandcommercialaudits.However,in thecaseofsingle-familyresidences,theapproachisgenerallysimpler.Residentialauditsareusuallyusedtoidentifycost-effective solutionstoamelioratethecomfortandefficiencyofbuildings.Inseveralcases,subjecthousesmayqualifyforenergyefficiency grants from governments. Energy auditors mainly focus on the analysis of the envelope thermal performance or quantify air leakages and examine the energy use and efficiency of residential applications, such as heaters, air conditioners, water heater, lighting,and“plugloads.”Theresidentialenergyauditshouldstartbyobtainingpastenergybillsandanalyzingthem.Sinceuser behaviorgreatlyaffectsenergyuseinresidentialbuildings,aninterviewofthehomeownerstounderstandtheirpatternsofuse overtimeisgenerallyrequired. Finally,awrittenreportregroupingtheimprovementslisttogetherwithcosts,benefits,andsimplepaybackperiods(PBs)is presentedtotheowner.Despitethesimplicityofenergyauditsintheresidentialsector,severalbarrierslimittheirwidespreaduse inmanypartsoftheworld.Themainbarriersarethelowpublicawarenessandthefinancialconstraintsrelatedtothecostsof energyaudits. 5.1.2.3 EnergyAudit Levels Thetypeofenergyauditsvariesdependingonmanyfactorsincluding: ● thefunction,type,size,andconfigurationofthestructureenergysystems; ● thedepthtowhichtheauditisrequired; ● theprojectspecificationsconfirmedbytheclient; ● thescopeandpotentialsproposedbytheenergyauditor;and ● thelevelandmagnitudeofprojectedenergysavingsandcostreductionintended. Theexactresultsofenergyauditsareusuallyquitecomplextobepredictedandtheeffortsthatwillbedeployedandtheircost effectivenessareinitiallyunknown.TheAmericanSocietyofHeating,RefrigeratingandAir-ConditioningEngineers(ASHRAE)has EnergyAuditing 5 definedthreeprogressivelevelsofaudits.Eachauditlevelreliesonthepreviouslevel.Obviously,thecomprehensivenessofthesite assessment,theamountofdatacollectedandthedetailprovidedinthefinalauditincreaseswiththeauditcomplexity,butthe potentialofenergysavingbecomeshigher.TheASHRAEenergyauditlevelsarediscussedbelow[10]. 5.1.2.3.1 ASHRAE Level 1 – walk-through analysis/preliminary audit TheLevel1audit,knownalsoas“walk-throughaudit,”“simpleaudit,”or“screeningaudit,”isthebasicstartingpointforenergy conservation. It is typically used in commercial buildings and small or medium industrial sites where the energy-consuming systemsarequitesimpleandthelikelyareasofpotentialenergy-savingmeasuresareknowninadvance. TheASHRAELevel1auditisgearedtowarddefiningthetypeandnatureofenergysystems,preliminarilyanalyzingthesite's energy consumption and identifying the simplest and most cost-effective energy upgrade measures. On this basis, in this audit type,readilyavailabledataaremostlyusedfortheanalysisofenergyuseandperformanceofthestructure.Limitedmeasurements arecarriedoutandextensivedatacollectionisnotrequired.Ashortreportlistingthefindingsandabasiceconomicanalysisofthe improvements is finally elaborated without necessarily providing detailed recommendations, except for very visible projects or operationalfaults. Despitethedegreeofsimplicityofthistypeofaudit,itmustbeconductedbyanexperiencedauditor.Thecompletiontimeof the"walk-through"auditisverylimitedandthereforetheauditorhastomakequickandcorrectandprofitabledecisions. 5.1.2.3.2 ASHRAE Level 2 – energy survey and analysis TheLevel2energyauditbeginswiththefindingsoftheLevel1audit,andevaluatestheenergysystemsoftheauditedstructurein moredetailtoproposeawiderangeofpotentialenergyefficiencyimprovements.Theapproachdiffersdependingonthestructure type(residential,commercial,orindustrialstructure),butinallcases,moredetaileddataandinformationareneeded. Detailedmeasurementsanddatainventoryareusuallycarriedoutanddifferentenergysystemsareextensivelyexamined. Theenergyefficiencymeasures(EEMs)forthisaudittypearenotdirectorobviousasinthecaseofLevel1auditandgenerally necessitatehigherinvestments. Forresidentialbuildings,theEEMsincludetheassessmentofthebuildingenvelope,HVACsystems,lightingdevices,domestic hotwaterproductionsystemand“plugloads.”Intheindustrialsector,thefocusismainlygearedtowardtheassessmentofhighly specializedequipment,suchascompressedair,Mots,andprocessmachines.Thefirststepinthistypeofauditistodeeplyanalyze theenergyconsumption;quantifybaseloads;identifyenergy-intensiveapplications,usagepatterns,andseasonalvariation;and determineenergycosts. Accordingtotheauditedstructure,duringtheauditprocess,thereshouldbedetaileddiscussionswiththebuildingownership or facility manager and facility operation and maintenance staff to identify potential problem areas, and clarify financial and nonfinancialtargetsoftheprogram. A clear and concise report, including an action plan to improve the energy efficiency, general future performances, and economicmetricsiswritten.Ameetingisthenplannedwiththeclienttoclarifytheauditresults,prioritizeEEMsandgivewaysto evaluateandimplementthem.Someoftheproposedmeasuresarelow-costorcanbeimplementedquickly,resultinginashort PB. Other measures require higher investments or considerable changes. Here, the auditor should help in the decision-making processanddefinethefirststepsoftheimplementationphase. 5.1.2.3.3 ASHRAE Level 3 – detailed analysis of capital intensive modifications Some of the system upgrades outlined by the Level 2 energy audit may require detailed analysis of possible capital-intensive modifications,includingmodelingandsimulation[11]. This type of audit, which is sometimes called an investment grade audit (IGA), is intended to provide supplementary engineering accuracy for more costly capital projects where uncertainty is less permitted since investors often demand guaranteed savings. Therefore, theLevel 3 audit involves acollection ofdataover alonger time period, an accuratemodeling ofEEMs, an estimationpower/energyresponse,detaileddesignofconstructiondocuments,anddetailedcostingestimates.Typically,ascopeof work and schematics are provided so that the contractors installing the measures understand exactly what is to be installed. Investmentlevelscanvaryfromtensofthousandstotensofmillionsofdollars. Dynamicsimulationsoftwarepackagesareoftenusedtoperformenergycalculationsinthisaudittype.Inthecaseofindustrial activities, data loggers typically will be employed to monitor operation modes of pumps and Mots, hourly temperatures and humidityvariationofaffectedspaces,switchingbehavior,andotherparameters.Thesedataarethenusedtocalibratethecomputer modelofthestructureanditsvariousenergysystems.Futurechangescanbeaccuratelysimulatedandtheresultsarethoroughly validated,whichgiveastrongsupportduringthedecision-makingprocess. 5.1.2.4 EnergyAudit: GeneralProcedure Toconduct anenergyaudit, asystematic approach isrequired inwhichthedepthofthedatacollection andanalysismight be different depending on the level, scope, and objectives of the audit. Generally, there are four main phases, each of which has severalsteps.ThesephasesandstepsarereportedinFig.1. 6 EnergyAuditing (1) Audit preparation (2) Audit execution Defining audit level, criteria and scope Data inventory and measurements Selection of audit team Analyzing energy use patterns Setting objectives Diagnosing energy systems Planning the audit Exploring and comparing opportunities Data collection Identifying potential EEMs Preliminary analysis Economical assessment (3) Audit reporting (4) Post-audit activities Writing the energy audit report Implementing EEMs Communicating with the client Checking performances Prioritizing and decision-making support Maintaining measures Fig.1 Energyauditprocedure.EEMs,energyefficiencymeasures. 5.1.2.4.1 Preparation phase Before starting the energy audit, the level, criteria, and scope against which the audit will be conducted should be defined. An energy audit team should be established to organize and manage the audit process, especially at the facility level where audit activities are more intense and often require various skills and capabilities. If needed, hiring outside experts is recommended to carry out a thorough audit. In this phase, it is also important to set objectives in harmony with site boundary, timeline, and staff involvement. As the audit process is generally complex, planning the activities to outline strategies and procedures is mandatory. The auditor may use checklists in order to conduct the work in a systematic and consistent way. Once these steps are performed, the data and information collection process can begin. Present and former energy use pattern, construction, andenergyutilization ofeverybuildingor unitshould becharacterized. Thesedataandinformationcan befound thanks toa well-structured and accurate questionnaire, which will be answered during the first meeting between the energy auditor and the client. 5.1.2.4.2 Execution phase Energyauditscantakefromfewweekstoseveralmonthstocomplete,dependingonthesitenatureandcomplexity.Theaudit processstartsattheutilitymeterswhereenergyflowsareidentifiedandsourcesofenergycomingintoabuildingorfacilityare measured.Datainventoryisestablishedtocharacterizetheuseandoccupancyoftheauditedstructure.Analysisofenergypatterns forspecificplantdepartmentsoritemsofprocessequipmentareinvestigated.Thediagnosisoperationsleadtoanidentificationof opportunities for energyefficiency improvements. These opportunities must becarefully assessed andcompared toidentify the mostappropriateones.OncethepotentialEEMsareselected,auditorsconductacost–benefitanalysistoevaluatetheireconomic viability. EnergyAuditing 7 5.1.2.4.3 Reporting phase In the final meeting, the energy auditor (or audit team) presents his or her conclusions explained in a well-structured format throughanenergyauditreport.Thereportneedstobeclear,conciseandprecise,providingsuitableinformationtothepotential readers. It starts with an explanation of the audit objectives, scope, and methodology and moves toward an overview of the auditedfacilityorbuilding.Thebodyofthereportincludesthemainauditfindings(energyuseandbudgetofthestructure,main identifiedanomaliesandcurrentperformances),adetaileddescriptionofrecommendedenergymeasuresclassifiedintermsofno cost/low cost, medium cost, and high investment cost along with the implementation costs, savings, and economic indicators. During the final meeting, an action plan for the implementation of the retained EEMs is proposed. Generally, the auditor prioritizesthepotential,direct,andlow-costopportunitiesandprovidessupportinthedecision-makingprocess. 5.1.2.4.4 Postaudit phase Inpractice,theimplementationofrecommendedimprovementsencountersseveralbarriers.Hence,establishingaclearprocedure toguaranteeafavorablerealizationoftheseimprovementsisrequired.Thisprocedureshouldclearlyoutlinegoals,savingtargets, and responsibilities for the implementation. The implementation phase should be achieved in a participative context with the focusonasmoothcommunication,anincreasedawareness,andaprofoundmotivation.Auditedstructurescanassessthebenefits oftheimplementedactivitiesbycomparingactualperformancesandconsumptionstotheestablishedgoalsusingenergydataand measurements.Theauditprocessiscompletedbysuggestionstomaintaintheauditresultsandensurethesustainabilityofenergy efficiencyimprovement. 5.1.3 Instrumentation for Energy Auditing Theenergyauditofenergyusenecessitatesmeasurements;thesemeasurementsrequiretheuseofaccurate,reliable,durable,easy touse,andrelativelyinexpensiveinstruments.Formeasuringandestimatingtherequiredparameters,itisimperativetoutilize accurateandcompletedatamonitoredforarepresentativeduration.Inpractice,however,completedataarerarelyavailable.The auditorhastocontrolperiodicallytheoperationalandmaintenancestatusoftheinstrumentsandassesstheirprobablemeasuring errortoensuretrustworthinessofmeasurements.Themeasuringactivityusingbothportableandinstalledinstrumentsgenerally occursduringtheexecutingphase,providinginstantaneousorshort-termrecordsofperformanceoverashorttimeinterval.Special careshouldbeconsideredwhenextrapolatingshort-termmeasurementstolonger-termresults.Inthiscase,itisadvisedtoperform measurementsduringperiodsthatarerepresentativeforeachequipmentoperation. Theparametersusuallymonitoredduringanenergyauditmaycoverthefollowing[12–14]: ● electricalmeasurementsincluding:voltage(V),currentintensity(A),powerfactor,activepower(kW),apparentpower(kVA), reactivepower(kVAr),energyconsumption(kWh),frequency(Hz),andharmonics; ● temperature,pressure,relativehumidity,radiation,heatflow,airvelocity,andluminancelevel; ● exhaustgazesemissionsandcontentsinCO ,O ,CO,SO,andNO; 2 2 x x ● liquidandgasfuelflows;and ● others,suchaspH,noiseandvibration,totaldissolvedsolids(TDS),revolutionsperminute(RPM). Auditorsshouldalwaysundertakemeasurementsoftheseparameterswithdueregardforsafetyrules,especiallywhendealing withspecificequipmentorprocesses. 5.1.3.1 Measuring Electrical Parameters Formeasuringtheelectricalparametersthefollowinginstrumentationisused. 5.1.3.1.1 Electric energy meters These measuring devices for electric energy are portable, quite simple, and do not require any special skills. The display, with whichitispossibletointeractbymeansofbuttons,canprovidethefollowingvalues: ● instantaneousvoltage; ● currentintensity; ● instantaneouspowerabsorbedbytheequipment; ● powerfactor; ● energyconsumed(EC)duringacertainperiod;and ● resultingeconomicvalueoftheEC. Themarketproposesawiderangeofthesedevicesataccessibleprices.Thelatestmodelsaresmartenergymetersthatprovide more precise and exact measures with supplementary functionality, such as real-time reads, power outage notices, and power qualitysupervision(Fig.2). 8 EnergyAuditing Fig.2 Energymetermanufacturedbycurrentcost.ReproducedfromCurrentcost.Availablefrom:www.currentcost.com[accessed18.08.16]. Fig.3 Electricalnetworkanalyzerconnectedtothemainbreaker.ReproducedfromTechni-Too.Availablefrom:www.techni-tool.com[accessed20.08.16]. 5.1.3.1.2 Electrical network analyzers Electrical network analyzers measure simultaneously the instantaneous voltage, current, and power factor. Their utilization requires specific skills in electrical engineering. The network analyzer is equipped with a communication cable connected to a computertotransferthedatarecorded(Fig.3).Thestoreddataareprocessedandanalyzedbyasoftwarepackage.Afteraproper EnergyAuditing 9 connectionofthisinstrumenttotheelectricalpanelofmachineryorthesubstationunderdiagnosis,measurementreadingscanbe displayedonitsscreenandinvolve: ● rootmeansquare(RMS)valuesofACvoltagesandcurrents ● peakvaluesforvoltagesandcurrents ● powerfactor ● active,reactivepower,andapparentpower ● frequenciesof50and60Hzelectricnetworks ● K-factorincurrentandvoltage ● distortionfactorofcurrentandvoltage ● totalharmonicdistortionforcurrentandvoltageandotherparameters 5.1.3.2 Internal ComfortMeasurements Six factors affect the thermal comfort of occupants. These factors can be distinguished into two classes: personal and environ- mentalfactors.Thepersonalfactorsincludetheclothinginsulationandthemetabolicheat.Theenvironmentalfactorsincludethe followingfactors[15]: ● airtemperature; ● meanradianttemperatureofwalls; ● airspeed;and ● relativehumidity. These parameters can be measured either instantaneously or continuously. The main devices used for this purpose are listedbelow. 5.1.3.2.1 Thermometers Air,gas,fluid,andsurfacetemperaturesarefrequentlycontrolledinanyaudittooptimizeenergyperformanceandquantifyheat lossesofasystem.Handleddigitalthermometersindicatethetemperaturevaluepreciselyontheirdisplay(Fig.4). Some thermometers indicate asingle measured value, while others are able tomeasure a series oftemperatures that can be storedforbeingprocessedlater. Beforeselectingathermometer,itisimportanttoconsideranumberofparametersincludingthemeasurementscale,accuracy, anddurability,aswellascostandapplicationtype.Themostusualtypesofthermometersensorsare: ● Thermocouples:thesedevicesareveryrugged,economical,andcanfunctionoveralargetemperaturefield.Athermocoupleis constructedwhenevertwodifferentmetalscomeintocontact,resultinginalowopencircuitvoltageatthecontactpoint,which Fig.4 HandhelddigitalthermometermanufacturedbyDavis.ReproducedfromDavis.Availablefrom:www.davis.com[accessed20.08.16]. 10 EnergyAuditing variesdependingonthetemperature(Seebeckeffect).Themost-usedthermocoupleisthenickel–chromium–nickel(NiCr-Ni) ortypesK.Thermocouplesrequirefrequentcalibration.Theirweaksignaleasilyaffectedbyindustrialnoiseremainstheirmain disadvantage. ● Resistancethermometerdetectors(RTDs):consideredamongthemosttechnologicallyadvancedinstruments,thesedetectors arebasedonthefactthat,inthecaseofcertainmetals,theresistanceincreasesasthetemperatureincreases.Theyarepowered byanexternalconstantcurrentwhosevoltagevariesproportionallywiththetemperaturemeasured. ● Negativethermalcoefficientthermistors:similarlytoRTDs,NTCthermistorsusethevariationofelectricalresistancetomeasure thetemperature.Thedifferenceisthat,inthecaseofNTCthermistors,theresistancedecreasesproportionallywithincreasesin temperature. 5.1.3.2.2 Infrared thermometers This is a noncontact type measurement that when oriented toward a heat source directly displays the temperature value. This instrumentisusefulformeasuringtemperaturesinfurnaces,movingobjects,corrosivesurfaces,invacuumreactor,orsubjectedto strongelectromagneticfields.Temperaturesensitivityrangesavailablearetypicallyfrom (cid:1)40to7001C.Theoperatingprincipleis basedonthetemperaturemeasurementbyquantificationoftheradiativeenergyemittedintheinfrared.Accuratemeasurements canbeachievedbyusinginfrared thermometerswithapossibilityofmanuallysettingthevaluesofenvironmentalparameters, suchasemissivityandairtemperature(Fig.5). 5.1.3.2.3 Anemometers Air speed measurements are performed using anemometers. They are principally employed to measure air flow from HVAC systems.TwotypesofanemometersareshowninFig.6: ● Rotating vane (left side): this instrument consists of a lightweight, air-driven vane, which is connected by a gearing system. Fromtherotatingfrequencyofthevanedeterminedusingarevcounter,airvelocityiselectronicallymeasured.Someofthe currentlycommercializedrotatingvalveanemometershaveadditionalfeaturesincludingsamplingandstatisticsfunctionsand dataloggingcapability. ● Hotwire(rightside):theprincipleisdissimilarforthisanemometertype.Afinewireisheatedelectricallyandplacedinthe flow stream. As the electrical resistance of most metals varies with the metal temperature, a relationship can be obtained betweentheresistanceofthewireandtheflowspeed.Theseinstrumentshavetheadvantageofbeingusedtomeasureairspeed insidesmallductsbecauseoftheirsmalldimensions.Nevertheless,therearequitecomplexandrelativelyexpensive. 5.1.3.2.4 Humidity measurements Humiditymeasurementsareusuallyrequiredintheenergyaudittoevaluatethecoolingloadexistinginasystemortoquantify theamountoflatentenergypresentinexhaustairflow.Forthistypeofmeasurement,thefollowinginstrumentsarethecommonly employedinaudits: ● Psychrometer: itisbased ontwothermometers; the firstis dryandtheother iscovered with acottoncloth moistened with distilled water. Given dry and wet bulb temperatures and barometric pressure, air humidity can be deduced using a Fig.5 PortableinfraredcameramanufacturedbyEnnoLogic.ReproducedfromEnnoLogic.Availablefrom:www.ennologic.com[accessed 20.08.16].