Building Energy Auditing

1 1 DEPARTMENT OF MINERALS AND ENERGYDME-Danida Capacity Building in Energy Efficiency & Renewable EnergyBuilding Energy AuditingEnergy Assessment andSavings OpportunityIdentificationDEPARTMENT OF MINERALS AND ENERGYDME-Danida Capacity Building in Energy Efficiency & Renewable EnergyModule 1: A Context forBuilding Energy AuditsEnergy Efficiency in SouthAfrican BuildingsDEPARTMENT OF MINERALS AND ENERGYDME-Danida Capacity Building in Energy Efficiency & Renewable EnergyModule 2: Basic Principles ofEnergyUnderstanding how energyworks in buildings2 DME Building Energy audit Course4 DEPARTMENT ofMINERALS and ENERGYL earning objectives]Define Energy in its various forms and Energy relatedproperties;]Use the correct units for Energy and power, and convertfrom one unit to another as needed;]Determine the properties of steam and moist air;]Describe the mechanisms by which heat is transferred.

2 ]Explain the effect of insulation on heat transfer, and themeans by which radiative heat transfer is Building Energy audit Course5 DEPARTMENT ofMINERALS and ENERGYE nergy in its variousforms]Chemical in fuels]Thermal sensibleand latent]Mechanical]ElectricalEnergy Equivalents 1000 joules (J) 1 kilojoule (kJ) 1 kilowatt-hour (kWh) 3,600,000 J or MJ DME Building Energy audit Course6 DEPARTMENT ofMINERALS and ENERGYB asic electricity]VoltageThis is what pushes electricity through a circuit - the driving force Units are Volts (V)]CurrentThis is what is pushed through by the voltage - the flow Units are Amperes (A) ( Amps , for short)3 DME Building Energy audit Course7 DEPARTMENT ofMINERALS and ENERGYE lectrical powerWhen voltage and current work together todo something useful - such as turn a motoror light a lamp Units are Watts 1000 Watts = 1 kilowatt (kW) 1 horsepower (HP) = 746 WattsDME Building Energy audit Course8 DEPARTMENT ofMINERALS and ENERGYAC/DC220 volts DC vs.

3 Time 220 01/50 sec 310 220 0 -310220 vo lts RMSDME Building Energy audit Course9 DEPARTMENT ofMINERALS and ENERGYC alculating power]Watts = Volts x Amps x Power Factor VA = Volts x Amps]Power factor (PF) indicates how well thecurrent and voltage are working togetherIncandescent Lamps100%Large Motors80-90%Small Motors60-75%4 DME Building Energy audit Course10 DEPARTMENT ofMINERALS and ENERGYP ower Factor - laggingcurrent 310 220 0 -310 310 220 0 -310 DME Building Energy audit Course11 DEPARTMENT ofMINERALS and ENERGYWhy should I care aboutpower factor?

4 ]Utilities may bill for Volts x Amps (kVA) or apply asurcharge for PF below a set value\Note that kVA is always greater than or equal tokW]Increased line currents]Low PF may suggest lightly loaded motors]Facilitates interpretation of electrical profilesDME Building Energy audit Course12 DEPARTMENT ofMINERALS and ENERGYP ower factor correction]Add capacitance\At service entrance\In distribution system\At point of use on motors5 DME Building Energy audit Course13 DEPARTMENT ofMINERALS and ENERGYP ower and Energy ]Power = How Fast(Demand)] Energy = How Much(Consumption)] Energy = Power x TimeUnits are kilowatt-hours (kWh)DME Building Energy audit Course14 DEPARTMENT ofMINERALS and ENERGYWhat is efficiency?

5 Electric HeatIncandescent LampMotorsPumps/Fan Air Compressor100% Elec - Heat10-20% Elec - Light50-95% Elec - Power20-60% Elec - Flow5-15% Elec - AirOutput InputEfficiency = x 100% Device Efficiency Input - OutputDME Building Energy audit Course15 DEPARTMENT ofMINERALS and ENERGYT hermal Energy units]Unit of thermal Energy is a Joule (J)\Typically use MJ or GJ.]1 Joule per second = 1 Watt]1 kWh = MJ ( GJ)]1 boiler HP = 9,810 Watts6 DME Building Energy audit Course16 DEPARTMENT ofMINERALS and ENERGYO ther useful units]1 kWh = 3413 BTU]

6 1 Ton of refrigeration= 12,000 BTU/Hr= kWDME Building Energy audit Course17 DEPARTMENT ofMINERALS and ENERGYS ensible and latentheat0EC for Water100EC for Water at Sea LevelSteam OnlyWater & SteamIce & W aterIceHeat RemovedHeat Added0% Steam Qua lity100% Steam QualityLa te nt He atLa te nt He atSe nsibleHeatSe nsibleHeatSe nsibleHeatDME Building Energy audit Course18 DEPARTMENT ofMINERALS and ENERGYH umid air -psychrometry7 DME Building Energy audit Course19 DEPARTMENT ofMINERALS and Energy Quality of heat - aquestion of usefulnessRequired Temperature: 60 ECRequired Energy : 16,800 kJ250 litres @ 100EC84,000 kJ1000 litres @ 40EC84,000 kJ100 litres@ 20 ECWhich will do thejob?

7 The 100 litres willbe heated byimmersing itscontainer in one ofthe Building Energy audit Course20 DEPARTMENT ofMINERALS and ENERGYL arge Body @ 20 ECSmall Body@ 60 ECConductionRadiationForcedConvectionCon vectionAir &Surrounding@ 20 ECHeat transfermechanismsDME Building Energy audit Course21 DEPARTMENT ofMINERALS and ENERGYT hermal resistance ofinsulationR = thickness/thermal conductivity8 DME Building Energy audit Course22 DEPARTMENT ofMINERALS and ENERGYC ontrolling heat loss -insulation]Types:\Fibrous\Cellular\Gran ular]Forms:\Rigid board\Flexible sheet\Flexible blankets\CementDME Building Energy audit Course23 DEPARTMENT ofMINERALS and ENERGYP rotective coverings]Weather barrier]Vapour retarder]Mechanical protection]Fire and corrosion resistance]Appearance coverings and finishes]Hygienic coveringsDME Building Energy audit Course24 DEPARTMENT ofMINERALS and ENERGYR adiation heat loss]Radiation from a hotbody to a cold body]Depends on\ , the emissivity ofthe surface\The temperaturedifference\The radiating area]Controlled byselecting low-emissivity materialsq = (Th4 - Tc4)

8 A9 DME Building Energy audit Course25 DEPARTMENT ofMINERALS and ENERGYHeat flow calculations]Conduction:\Q = U x A x (T2 - T1)]Air flow:\Q = V x (T2 - T1) x ]Humid air:\Q = V x (H2 - H1) x ]In liquids:\Q = M x (T2 - T1) x C x1000]Pipe heat loss:\Q = F x L]Refrigeration:\Q = COP x Power toCompressor (kW)]Steam leaks:\Q = M x h / 3600 DEPARTMENT OF MINERALS AND ENERGYDME-Danida Capacity Building in Energy Efficiency & Renewable EnergyModule 3: Overview ofBuilding Energy AuditsA Systematic Approach toEnergy AuditingDME Building Energy audit Course27 DEPARTMENT ofMINERALS and ENERGYL earning objectives]Describe the theoretical framework for abuilding audit ;]Identify the information that should be collectedand analysed before the site visit;]Develop a Building audit plan and schedule;]Identify the steps involved in conducting abuilding Building Energy audit Course28 DEPARTMENT ofMINERALS and ENERGYWhat is energyauditing?

9 An Energy audit is developing an understanding of the specific Energy using patterns of a particular facility. Carl E. Salas, An Energy audit is developing an understanding of the specific Energy using patterns of a particular facility. Carl E. Salas, DME Building Energy audit Course29 DEPARTMENT ofMINERALS and ENERGYHow is energymanagement done?]Purchase energysupplies at thelowest possibleprice.]Manage Energy useat peak efficiency.]Utilize the Building Energy audit Course30 DEPARTMENT ofMINERALS and ENERGYM anaging Technology]No cost -housekeepingmeasures]Low cost - sometechnology, lots ofpeople input]High cost - capitalinvestment11 DME Building Energy audit Course31 DEPARTMENT ofMINERALS and ENERGYE nergy consumingsystems in buildingsOrganization /SiteBuilding BDepartment BDepartment ADepartment CSystem BSystem ASystem CEquipment ABuilding ADepartment.

10 System _System CEquipment BDME Building Energy audit Course32 DEPARTMENT ofMINERALS and ENERGYA basis for the Energy audit .. what comes in, goes outOil or Natural GasEnergy InflowBoiler Stack LossExha ustWarm Fluid to DrainDo or He at LossWall He at L ossWindowHeat LossVentilationProcess Exhau stElectricityEnergy Inflo wSolarEnergy InflowEnergy System BoundaryDME Building Energy audit Course33 DEPARTMENT ofMINERALS and ENERGYTwo levels of audit ]Preliminary audit \High level assessment\Assesses merits ofdoing detailed audit \Identifies areas offocus for detailedaudit\Includes walk-throughand preliminary dataanalysis]