PRO-CEA

Final check — CEA — Certified Energy Auditor (Exam-Prep)

Answer the 130 questions. You need 80% or more to pass. You can retry as many times as you like.

Question 1A facility manager wants a quick assessment that reviews historical utility bills, conducts a brief walk-through, and identifies low-cost/no-cost savings without detailed engineering analysis. Which ASHRAE audit level best matches this request?Level 1 - Walk-Through AnalysisLevel 2 - Energy Survey and Engineering AnalysisLevel 3 - Detailed Analysis of Capital-Intensive ModificationsLevel 0 - Benchmarking only

Question 2Which ASHRAE audit level provides detailed savings and cost analysis, a breakdown of energy use by end use, and a list of energy conservation measures with savings, costs, and economic analysis suitable for most owners' decision-making?Level 1Level 2Level 3Level 4

Question 3An ASHRAE Level 3 audit is distinguished primarily by which of the following?Reliance only on utility bill analysis with no site visitA brief walk-through with order-of-magnitude estimatesRigorous engineering analysis and detailed data (including hourly simulation/monitoring) to support capital-intensive measuresSchematic design only without cost estimates

Question 4Before visiting a site, an energy auditor compiles 24-36 months of utility bills to establish baseline consumption and demand patterns. This activity is best described as:Measurement and verification (M&V)Preliminary energy-use analysis / benchmarkingCommissioningRetrofit isolation

Question 5The Energy Use Intensity (EUI) of a building is best defined as:Annual energy cost divided by occupancyAnnual energy consumption per unit of gross floor area (e.g., kBtu/ft²·yr or kWh/m²·yr)Peak demand divided by connected loadTotal energy use multiplied by the load factor

Question 6On a steam boiler, the auditor measures 4% O2 and finds the stack temperature is 150°C above combustion-air temperature. To reduce stack (flue gas) losses, the MOST appropriate first action is to:Increase excess air to ensure complete combustionRecover stack heat (e.g., economizer/air preheater) and trim excess air toward the optimumLower the feedwater temperatureReduce boiler operating pressure to cut losses

Question 7A boiler operates with 3% O2 in the flue gas. If excess oxygen rises to 8% at the same firing rate, what is the most likely effect on boiler efficiency?Efficiency increases because more oxygen ensures complete combustionEfficiency decreases because excess air carries heat up the stackEfficiency is unchanged; O2 has no effect on lossesEfficiency increases because flue gas temperature drops

Question 8During a steam system audit, the auditor finds a failed-open steam trap blowing live steam continuously. The PRIMARY energy concern with this failure mode is:Condensate freezing in the return lineContinuous loss of usable steam energy to the condensate/return systemWater hammer eliminating all heat transferExcessive condensate subcooling improving efficiency

Question 9Installing a feedwater economizer on a boiler recovers heat from the flue gas to preheat boiler feedwater. As a rule of thumb, boiler efficiency improves approximately:1% for roughly every 40°F (about 22°C) reduction in stack gas temperature10% for every 40°F reduction in stack gas temperature1% for every 1°F reduction in stack gas temperatureThere is no relationship between stack temperature and efficiency

Question 10A plant blows down 5% of its boiler feedwater continuously to control dissolved solids. The MOST effective measure to recover energy from this blowdown is to:Install a blowdown flash tank and/or heat exchanger to recover heatIncrease the blowdown rate to 10%Eliminate water treatment entirelyRaise the steam pressure to reduce blowdown

Question 11An auditor evaluates bare, uninsulated steam piping in a boiler room. Adding insulation to this piping primarily reduces:Pressure drop along the steam mainStanding/radiation heat losses from the pipe surfaceThe boiler's excess air requirementCondensate pump electrical demand

Question 12A boiler's combustion efficiency is most directly determined from which two measured flue gas parameters?Feedwater pH and conductivityFlue gas temperature and excess air (from O2 or CO2)Steam pressure and condensate flowFuel cost and operating hours

Question 13Recovering condensate and returning it to the boiler (rather than sending it to drain) saves energy chiefly because the condensate:Has zero dissolved oxygen by definitionIs hot, treated water that reduces makeup water, fuel, and chemical useLowers the steam pressure requiredIncreases boiler blowdown requirements

Question 14At an ASHRAE Level 2 audit, the auditor disaggregates whole-building energy into lighting, HVAC, plug loads, and process. The PRIMARY purpose of this end-use breakdown is to:Satisfy utility billing requirementsTarget conservation measures where the largest savings opportunities lieReplace the need for any field measurementsDetermine the building's occupancy classification

Question 15A 600 hp boiler fires natural gas. The auditor wants to reduce excess air using an oxygen trim system. The benefit of O2 trim control is that it:Maintains minimum safe excess air automatically as load and conditions varyEliminates the need for a combustion-air fanIncreases flue gas temperature for better heat transferRemoves all CO from the flue gas regardless of tuning

Question 16In a Level 1 ASHRAE audit, identified opportunities are typically limited to which category?Major capital projects requiring detailed simulationLow-cost / no-cost measures and potential capital improvements warranting further studyOnly measures with payback over 10 yearsOnly utility rate renegotiation

Question 17A steam system operates at 150 psig. The plant could meet all process loads at 100 psig. Reducing header pressure to 100 psig would generally:Increase fuel use because more steam mass is neededReduce flash-steam and radiation losses and lower fuel useHave no measurable effect on energy useRequire larger boilers immediately

Question 18An auditor reviews a building with high summer electric demand charges. To understand WHEN peak demand occurs, the most useful data source is:Interval (15-minute) demand data from the utility meterThe building's nameplate connected loadThe annual total kWh onlyThe boiler combustion analysis

Question 19A combustion analyzer reports rising CO along with low O2 in a boiler's flue gas. This combination most likely indicates:Too much excess airInsufficient combustion air causing incomplete combustionA failed feedwater pumpExcessive blowdown

Question 20For a thermal/process heating audit, the auditor calculates that a furnace has a high stack loss and a low available heat. The single most cost-effective measure is often to:Preheat combustion air using a recuperator on the flueIncrease the firing rate to overcome lossesOpen the furnace doors to relieve pressureRemove all refractory insulation

Question 21When establishing the audit baseline, the auditor normalizes building energy use against heating and cooling degree days. The purpose of weather normalization is to:Convert energy units from kWh to BtuSeparate weather-driven variation from changes due to operation or retrofitsIncrease reported savings artificiallyEliminate the need to read utility bills

Question 22A scoping (preliminary) audit identifies that a 1,000-ton chiller plant, a steam boiler plant, and lighting all show savings potential. To decide which system warrants the deeper, capital-intensive ASHRAE Level 3 study, the auditor should prioritize based on:The system that is newest regardless of consumptionThe magnitude of energy/cost savings potential and measure complexity/costWhichever system the operator personally prefersThe system with the smallest connected load

Question 23An auditor needs to log the true-RMS power draw of a 3-phase, 480 V motor over one week to capture its actual duty cycle. Which instrument setup is most appropriate?A single clamp-on ammeter read once at the panelA data-logging 3-phase power meter with current transformers and voltage leads on all phasesA handheld light meter positioned near the motorA utility bill analysis for the past 12 months

Question 24When measuring current with a clamp-on ammeter on a single conductor of a balanced 3-phase load, why can total power NOT be found from current alone?Voltage and power factor are also required to compute real powerClamp meters cannot read AC currentCurrent is identical to power in kWThree-phase loads have no measurable current

Question 25An auditor uses an infrared thermography camera on a building exterior in winter. A bright (warm) patch around a window frame most likely indicates:Excellent insulation at that locationAir leakage or thermal bridging causing heat lossA reflective surface only, never a real defectHigher-than-normal indoor humidity

Question 26Which instrument is the standard tool for quantifying building envelope air leakage as a whole?Blower door with a calibrated fan and manometerThermal anemometer in a ductCombustion flue-gas analyzerUltrasonic flow meter on a pipe

Question 27A combustion analyzer reports flue O2 of 9% and high stack temperature on a gas boiler. The primary efficiency conclusion is that the boiler has:Optimal combustion with no adjustment neededExcess air and high stack losses, reducing combustion efficiencyInsufficient air leading to soot onlyA condensing operation at peak efficiency

Question 28To verify a chiller's actual cooling output during an audit, which combination of measurements is needed to compute kW/ton?Only the chiller's nameplate tonnageChilled-water flow, supply/return water temperatures, and electrical power inputOutdoor air temperature and lighting loadBoiler stack temperature and flue O2

Question 29An auditor places a portable data logger to record space temperature and relative humidity every 15 minutes for two weeks. The main purpose of this logging interval and duration is to:Capture operating patterns and schedules rather than a single snapshotReduce the logger's battery life intentionallyEliminate the need for any utility dataMeasure combustion efficiency directly

Question 30Under IPMVP, the period of energy use established before an ECM is installed, used as the basis of comparison, is called the:Reporting periodBaseline periodGuarantee periodCommissioning period

Question 31In IPMVP, 'avoided energy use' (savings) for a reporting period is best expressed as:Reporting-period energy minus baseline energyAdjusted-baseline energy minus reporting-period energyBaseline energy plus reporting-period energyReporting-period energy divided by baseline energy

Question 32An ECM affects only a lighting circuit in one zone, and the savings can be isolated by metering that circuit before and after. Which IPMVP Option is most appropriate?Option A or B (Retrofit Isolation)Option C (Whole Facility)Option D (Calibrated Simulation)No IPMVP option applies to lighting

Question 33The key distinction between IPMVP Option A and Option B is that:Option A measures all parameters continuously; Option B uses stipulated valuesOption A measures key parameters and stipulates others; Option B measures all parametersOption A uses whole-building utility bills; Option B uses simulationThey are identical and interchangeable

Question 34A facility-wide ECM package is verified using monthly utility bills with a regression model against weather. This is an example of which IPMVP Option?Option AOption BOption C (Whole Facility)Option D (Calibrated Simulation)

Question 35When measured baseline data is unavailable (e.g., a new building or many interactive ECMs), which IPMVP Option relies on an energy model tuned to actual utility data?Option AOption BOption COption D (Calibrated Simulation)

Question 36In M&V, a 'routine adjustment' to the baseline accounts for:One-time changes such as adding a new wing to the buildingIndependent variables that vary routinely, such as weather and occupancyErrors made by the metering technicianThe cost of the M&V plan itself

Question 37A 'non-routine adjustment' in IPMVP would be required when:Outdoor temperature changes from day to dayOccupancy fluctuates normally each weekStatic factors change, e.g., a permanent change in operating hours or added equipmentThe utility issues an estimated bill for one month

Question 38A regression model of monthly energy vs. cooling degree-days yields R² = 0.94 and a low CV(RMSE). This indicates the model:Poorly explains the variation and should be rejectedExplains most of the variation and fits the data wellProves savings exist regardless of the dataIs invalid because R² must equal 1.0

Question 39A lighting retrofit replaces 200 fixtures of 150 W each with 60 W LEDs, operating 4,000 hours/year. The annual energy savings is approximately:18,000 kWh48,000 kWh72,000 kWh120,000 kWh

Question 40For the same retrofit (200 fixtures, 90 W reduction each), what is the demand reduction if all fixtures operate coincident with the utility peak?1.8 kW9 kW18 kW30 kW

Question 41A measurement boundary in an M&V plan is best described as:The physical and conceptual limits within which energy effects are determinedThe maximum kWh the meter can recordThe deadline for submitting the audit reportThe contractor's warranty period

Question 42When selecting metering equipment for M&V, an auditor should ensure the instrument's accuracy is:Far coarser than the expected savings so cost is minimizedCommensurate with the magnitude of the savings being verifiedIrrelevant because regression corrects all errorsAlways 0.01% regardless of application

Question 43An ultrasonic clamp-on flow meter is chosen over an inline meter for measuring chilled-water flow during an audit primarily because it:Requires cutting into the pipe and draining the systemIs non-intrusive and can be installed without shutting down the systemMeasures electrical power instead of flowOnly works on gas pipes

Question 44Before relying on logged data, an auditor should compare short-term measured power against utility billing demand. This step is best described as:Data validation / cross-checking for consistencyStipulating values to avoid measurementCalculating simple paybackDefining the building envelope

Question 45A 2,000 ft² wall assembly has a measured U-factor of 0.10 Btu/h·ft²·°F. During a heating season with 6,500 heating degree-days (base 65°F), what is the approximate annual conductive heat loss through the wall (ignoring solar and infiltration)?About 3.12 million Btu/yearAbout 1.3 million Btu/yearAbout 31 million Btu/yearAbout 13 million Btu/year

Question 46An auditor evaluates adding R-19 insulation to an existing R-3 (effective) wall. What is the percentage reduction in conductive heat loss through that wall (assuming the U-factor is the inverse of the R-value)?About 14%About 50%About 86%About 95%

Question 47Two ECMs are mutually exclusive. ECM A costs $20,000 and saves $5,000/yr; ECM B costs $50,000 and saves $9,000/yr. Using simple payback as the primary screen, which statement is most defensible?B is better because it saves more dollars per yearA has the shorter payback (4 yr vs 5.6 yr), but payback alone ignores measure life and time value of moneyBoth are identical because both pay back within a decadeNeither should be considered without a 20-year payback

Question 48A roof ECM costs $40,000, saves $8,000/year, and has a 15-year life. At a 6% discount rate, the present-worth factor (uniform series, 15 yr, 6%) is 9.712. What is the approximate Net Present Value?About $77,700 (positive, attractive)About -$40,000About $37,700About $120,000

Question 49During an envelope audit, an infrared thermographic scan of an exterior wall in winter shows distinct cold streaks aligned with the stud cavities while the studs appear warmer. What does this most likely indicate?Missing or settled cavity insulation between the studsExcessive thermal bridging through the studs onlyAir leakage at the wall plateNormal, expected behavior for an insulated wall

Question 50A building's design heat loss is calculated from envelope U-factors, areas, and the indoor-to-outdoor temperature difference. If the design indoor temperature is raised from 70°F to 72°F while outdoor design is 10°F, the conductive design heat loss increases by approximately what percentage?About 2.9%About 20%About 0.3%About 10%

Question 51An ECM bundle has an internal rate of return (IRR) of 18% and the organization's minimum acceptable rate of return (hurdle rate) is 12%. What is the correct economic interpretation?Reject; IRR should equal the discount rate exactlyAccept; the project return exceeds the hurdle rate, so NPV at 12% is positiveReject; an 18% IRR indicates an unrealistic estimateIndeterminate without knowing the payback period

Question 52A single-pane window (U = 1.04) covering 300 ft² is replaced with a low-e double-pane unit (U = 0.30). For a location with 5,000 heating degree-days (base 65°F), the annual conductive heating energy saved is approximately:About 26.6 million Btu/yearAbout 2.66 million Btu/yearAbout 53 million Btu/yearAbout 1.1 million Btu/year

Question 53In life-cycle cost analysis of two ECMs with different lifetimes (10 yr vs 20 yr), which approach correctly compares them on an equal basis?Compare simple payback only; lifetime is irrelevantUse equivalent uniform annual cost, or evaluate over a common study period with replacement/residual valuesAlways select the measure with the longer lifeCompare first costs only since they are paid up front

Question 54An auditor computes a wall assembly U-factor. The wall has parallel paths: insulated cavity (R-13) at 75% of area and wood studs (R-7) at 25% of area, plus continuous layers totaling R-2 on both faces. Using the parallel-path (isothermal-planes) method, the cavity and stud R-values are combined by:Simply adding R-13 and R-7Area-weighting the U-factors (conductances) of each path, then adding series layersTaking the higher of the two R-valuesAveraging the two R-values arithmetically (R-10)

Question 55A facility manager insists on a maximum 3-year simple payback for any ECM. A high-efficiency boiler ECM costs $90,000 and saves $25,000/year. Does it pass the screen, and what is the key limitation of this decision rule?Fails (3.6 yr); the rule ignores long-term savings beyond payback and time value of moneyPasses (2.8 yr); no limitationsFails (4.5 yr); the rule is fully reliablePasses (3.0 yr); payback captures all economics

Question 56A blower-door test reports 3,000 CFM50. To estimate the natural infiltration rate, an auditor divides CFM50 by an N-factor (LBL method) appropriate for the climate and building height. The purpose of this N-factor is to:Convert the pressurized test flow to an estimate of average natural-condition airflowConvert CFM to ACH50 directlyAccount for the duct leakage separatelyCalibrate the blower-door fan

Question 57An ECM saving 200,000 kWh/year at a blended rate of $0.11/kWh also reduces demand by 30 kW/month at $14/kW. Ignoring escalation, what is the total annual cost savings?$22,000$27,040$22,420$26,200

Question 58When estimating envelope heating loads, the degree-day method is most appropriate for which type of building?A building dominated by skin (envelope) loads with a fairly constant indoor setpoint and modest internal gainsA high-internal-gain office with large variable plug and lighting loadsA data center running at constant cooling load year-roundAny building, since internal gains never affect the balance point

Question 59The savings-to-investment ratio (SIR) of an ECM is defined as the ratio of the present value of savings to the present value of investment costs. An ECM with SIR = 0.85 means:The measure is cost-effective with margin to spareThe measure is not cost-effective; discounted savings are less than discounted costsThe measure pays back in 0.85 yearsThe measure has a negative IRR

Question 60A flat roof has the following layers (R-values): exterior air film 0.17, membrane 0.0, rigid insulation R-20, metal deck ~0, interior air film 0.61. Approximately what is the assembly U-factor?About 0.048 Btu/h·ft²·°FAbout 0.20 Btu/h·ft²·°FAbout 0.005 Btu/h·ft²·°FAbout 0.50 Btu/h·ft²·°F

Question 61For a cooling-dominated climate, which window property most directly governs solar heat gain through glazing and is therefore a key envelope ECM target?U-factorSolar Heat Gain Coefficient (SHGC)Visible transmittance (VT)Air leakage rating

Question 62An ECM costs $60,000 and produces savings of $10,000 in year 1, escalating 4% per year over a 10-year life. Compared with a simple-payback estimate using constant year-1 savings (6 years), the escalation-adjusted analysis will:Show a longer effective payback and lower NPVShow a shorter effective payback because later savings are largerBe identical to the simple paybackMake the project uneconomic regardless of life

Question 63During an ASHRAE Level II audit, an auditor must report the building's overall envelope performance. The most appropriate single normalized metric to benchmark envelope-driven loss across buildings of different sizes is:Total annual Btu loss onlyA normalized metric such as UA per unit floor area or design heat loss per ft²The number of windows in the buildingThe installed boiler capacity

Question 64A wall ECM saves 40 MMBtu/yr of natural gas. The boiler that delivers this heat has a seasonal efficiency of 80%, and gas costs $9.00/MMBtu. What is the correct annual fuel cost savings the auditor should report?$360 (using delivered heat only)$450 (delivered heat divided by 0.80, times $9)$288 (delivered heat times 0.80, times $9)$405

Question 65An auditor finds a building with significant thermal bridging at concrete balcony slabs penetrating the insulated facade. Beyond conductive heat loss, the most important secondary concern to flag in the report is:Risk of interior surface condensation and mold at the cold bridgeIncreased solar heat gain through the slabReduced daylighting in the spaceHigher visible transmittance of the glazing

Question 66Two ECMs each pass a 5-year payback screen. ECM X has NPV $30,000 over a 10-year life; ECM Y has NPV $18,000 over a 10-year life, but the capital budget only allows one. Using NPV as the decision criterion for mutually exclusive projects of equal life, the auditor should recommend:ECM Y, because lower NPV means lower riskECM X, because it maximizes net present value for equal-life mutually exclusive optionsWhichever has the higher SIR, regardless of NPVNeither, since both must be deferred

Question 67During a Level 2 audit of a 50,000 ft² office, an auditor finds the central VAV system delivers a constant 55°F supply air year-round while terminal boxes reheat in many zones during winter. Which control change typically yields the largest fan and reheat energy savings?Supply air temperature reset based on zone demandLowering the chilled water setpoint by 5°FIncreasing minimum outdoor air to all zonesReplacing terminal box dampers with manual balancing dampers

Question 68An auditor measures a constant-volume AHU running 24/7 in a building occupied only 60 hours/week. The first-recommended low-cost ECM is most likely:Install premium-efficiency motor on the supply fanImplement occupancy-based scheduling / night setback of the AHUAdd a desiccant dehumidification wheelReplace the cooling coil with a larger one

Question 69A rooftop unit's economizer is found stuck closed. The energy penalty is greatest in which condition?Hot, humid summer afternoonsMild outdoor air with a cooling load (free-cooling hours)Cold winter nights with no cooling loadUnoccupied periods with the fan off

Question 70A 100-ton chiller measured at 0.85 kW/ton at full load is rated for 0.62 kW/ton. The MOST useful next diagnostic step before recommending replacement is to:Immediately recommend a new magnetic-bearing chillerCheck condenser approach/fouling, refrigerant charge, and condenser water temperatureRaise the chilled water setpoint to mask the problemDisable the chiller and rely on the economizer

Question 71Which HVAC measure best targets reducing the part-load energy of a constant-speed chilled water pump in a system with two-way control valves?Add a variable frequency drive with differential pressure controlInstall a larger impellerReplace two-way valves with three-way valvesThrottle the pump discharge with a balancing valve

Question 72An auditor wants to quantify HVAC fan savings from a VFD retrofit. According to the fan affinity laws, reducing fan speed to 70% of design reduces ideal shaft power to approximately:70% of design power49% of design power34% of design power85% of design power

Question 73A building has simultaneous heating and cooling because the AHU minimum airflow forces reheat. The cleanest first investigation is to review:The lighting power density of the zonesVAV box minimum airflow setpoints versus actual ventilation requirementsThe roof insulation R-valueThe domestic hot water recirculation schedule

Question 74In an energy audit report, recommendations are MOST useful to a decision-maker when they are presented:Alphabetically by equipment namePrioritized by financial metrics (e.g., simple payback, NPV) with cost and savingsAs a single lump-sum total with no breakdownOnly in technical engineering terms without dollar figures

Question 75An auditor presents three ECMs: lighting retrofit (1.5-yr payback), VFD on cooling tower fans (3-yr), and chiller replacement (12-yr). For a client with limited capital seeking quick wins, the recommended implementation sequence is typically:Chiller, VFD, then lightingLighting, VFD, then chiller (shortest payback first)All three simultaneously regardless of budgetOnly the chiller because it is the largest

Question 76A report claims 18% HVAC savings from a control upgrade. To make the claim credible and verifiable per IPMVP, the report should include:Only the projected annual dollar savingsThe baseline definition, measurement boundary, and M&V approach usedA list of the auditor's certifications onlyThe manufacturer's marketing brochure

Question 77A heating-dominated facility uses an air-source heat pump that locks into electric resistance backup below 35°F. Which audit finding most justifies recommending controls/setpoint changes?Excessive use of resistance heat during mild outdoor temperatures due to a high balance-point lockoutThe heat pump runs efficiently at design heatingThe compressor cycles normally in cooling modeThe condensate drain is clear

Question 78When estimating annual cooling energy from a short-term audit, the BEST approach for relating measured load to weather is to use:A single peak-day measurement extrapolated linearlyCooling degree-days or a bin/regression analysis against outdoor temperatureThe equipment nameplate capacity multiplied by 8760 hoursThe building's gross floor area alone

Question 79An auditor finds outdoor air dampers fixed at 30% on a system serving an office with low occupancy. Adding demand-controlled ventilation (DCV) saves energy primarily by:Increasing supply fan static pressureReducing the volume of conditioned outdoor air when CO₂ indicates low occupancyRaising the chilled water temperatureEliminating all outdoor air ventilation

Question 80A maintenance-related HVAC ECM with essentially zero capital cost and immediate savings, often the first recommendation in any audit, is:Full duct system replacementCleaning/replacing clogged filters and coils and fixing dirty heat-transfer surfacesInstalling a new chiller plantAdding a thermal energy storage tank

Question 81An executive summary in an energy audit report should primarily contain:Detailed psychrometric calculations and equipment cut sheetsKey findings, total recommended savings, costs, and overall payback for decision-makersRaw logger data tablesThe full instrumentation calibration logs

Question 82After implementation of an HVAC ECM, the client questions whether the predicted savings materialized. The auditor should reference which document/process to resolve this?The original equipment warrantyA measurement and verification (M&V) plan comparing adjusted-baseline to post-retrofit useThe fire safety inspection reportThe architectural floor plans

Question 83An auditor recommends raising chilled water supply temperature from 42°F to 45°F to improve chiller efficiency. The MAIN risk that must be checked and noted in the report is:Reduced latent dehumidification capacity and possible humidity/comfort issuesIncreased pump motor nameplate voltageHigher lighting power densityLoss of the building's R-value

Question 84A facility's BAS trend logs show the heating and cooling valves both open at the same AHU during shoulder seasons. The most likely root cause an auditor should report is:A control sequence with overlapping/no deadband between heating and coolingUndersized electrical serviceExcessive window-to-wall ratioA failed parking-lot light photocell

Question 85Two HVAC ECMs are recommended together: a VFD on the supply fan and an AHU scheduling change. When calculating combined savings, the auditor must account for:Interactive effects, since scheduling reduces the run-hours over which the VFD also savesNothing; savings always add linearlyOnly the larger of the two measuresThe lighting interactive heat gain only

Question 86For implementation, an audit report's ECM table should ideally include cost, savings, payback, AND:The auditor's home addressAvailable utility rebates/incentives and any implementation dependencies or risksThe weather forecast for next monthA list of competing audit firms

Question 87An auditor measures supply and return air temperatures across a cooling coil and airflow with a flow hood/grid to compute coil cooling load. This sensible load is best calculated using:Q = 1.08 × CFM × ΔT (sensible)Q = CFM ÷ ΔTQ = voltage × current × power factorQ = R-value × area × ΔT

Question 88A client asks the auditor to omit a recommended but unpopular ECM (occupancy scheduling that affects after-hours users) from the report. The auditor's most professional action is to:Delete it entirely to satisfy the clientInclude it with documented savings while clearly noting operational impacts and constraintsReplace it with an unrelated higher-cost measureOverstate its savings to force adoption

Question 89An auditor measures a fluorescent troffer drawing 86 W (lamps plus ballast) and proposes a 32 W LED replacement panel. What is the connected-load reduction per fixture?54 W32 W86 W118 W

Question 90A warehouse has 200 high-bay fixtures at 400 W each operating 6,000 hours/year. Retrofitting to 150 W LED high-bays cuts annual energy use by approximately how much?180,000 kWh300,000 kWh480,000 kWh100,000 kWh

Question 91Which photometric quantity, expressed in lux or foot-candles, should an auditor measure at the working plane to verify adequate task lighting?Luminous fluxLuminanceIlluminanceLuminous intensity

Question 92A lamp produces 4,000 lumens while drawing 40 W. What is its luminous efficacy?160 lm/W40 lm/W100 lm/W400 lm/W

Question 93During a daytime walkthrough of a perimeter office with large windows, the auditor finds lights fully on. Which control measure best captures daylight savings here?Time-clock scheduling onlyDaylight-harvesting photosensor dimmingBi-level switching by lamp countManual master switch

Question 94A T12 lamp system is replaced with LED. Beyond lamp wattage, why must the auditor account for the existing magnetic ballast?Magnetic ballasts add parasitic losses removed by ballast-bypass LEDBallasts increase the color rendering indexBallasts have no effect on input powerBallasts raise lumen output of LED lamps

Question 95An occupancy sensor is proposed for a storeroom occupied only 25% of the time, currently lit 4,000 hours/year. Estimate the annual operating hours after the retrofit (ignoring sensor time-delay).3,000 hours2,000 hours500 hours1,000 hours

Question 96Which factor is included in the IESNA lighting power density (LPD) metric used to benchmark a space?Watts per square foot (or per square meter)Lumens per fixtureColor temperature in kelvinFoot-candles per lamp

Question 97A retrofit reduces lighting load by 18 kW. Because the lamps were inside a conditioned, cooled space, what secondary benefit should the auditor quantify?Reduced cooling load (interactive HVAC savings)Increased heating energy with no offsetHigher ballast factorReduced power factor penalty only

Question 98In a heated-only space in a cold climate, an efficient lighting retrofit may show a 'heating penalty.' What does this mean for net savings?Lost heat from lamps must now be supplied by the heating system, reducing net savingsNet savings increase because heating is cheaperLighting and heating are unrelatedCooling penalty replaces heating penalty

Question 99An office currently maintains 750 lux but the task only requires 500 lux per IES recommendations. What is this condition called and the appropriate measure?Under-lighting; add fixturesOver-lighting; reduce/delamp or dimCorrect lighting; no actionGlare; relocate windows

Question 100A facility runs 320 LED fixtures at 45 W, 4,200 hours/year, at $0.11/kWh. What is the approximate annual lighting energy cost?$6,653$2,500$13,300$1,200

Question 101When selecting LED replacements for a retail space displaying merchandise colors, which lamp parameter is most critical to preserve appearance?Color rendering index (CRI)Power factorTotal harmonic distortionBallast factor

Question 102A lighting retrofit costs $42,000 and saves $14,000/year in energy and maintenance. What is the simple payback period?2.0 years3.0 years4.2 years1.5 years

Question 103An auditor wants to verify actual lighting operating hours rather than rely on occupant estimates. Which instrument is most appropriate?Infrared thermometerA light-logger (lighting runtime data logger)Combustion analyzerAnemometer

Question 104Replacing a 250 W metal-halide HID fixture (with a 290 W input including ballast) with a 100 W LED equivalent gives what input-watt savings per fixture?150 W190 W250 W100 W

Question 105Which retrofit strategy keeps existing lamps but improves delivered light and reduces required lamp count by improving fixture optics?Installing high-performance reflectorsIncreasing voltage to lampsAdding a step-up transformerRaising the ballast factor

Question 106In a 24/7 data center corridor lit continuously, why would an occupancy-sensor retrofit yield little savings compared to a delamping measure?The space has near-constant occupancy/operation, so few off-hours exist to captureSensors do not work in corridorsDelamping is always cheaper than any controlOccupancy sensors increase wattage

Question 107An auditor records 60 W measured at a fixture but the lamp is rated 54 W. The ratio of actual fixture output to rated lamp lumens partly depends on which factor describing actual vs. rated drive?Ballast factorCrest factorDiversity factorLoad factor

Question 108For measurement and verification of a lighting retrofit, which IPMVP option uses pre/post fixture-level metering and stipulated operating hours rather than whole-building data?Option A (Retrofit Isolation: Key Parameter)Option C (Whole Facility)Option D (Calibrated Simulation)Option E (Utility Bill Only)

Question 109A 1,000-fixture office retrofit saves 30 kW of demand. With a $12/kW-month demand charge, what is the approximate annual demand-charge savings (assuming the reduction occurs every billing month)?$4,320$360$10,800$1,440

Question 110A 100 hp motor operates at 85% loading with a measured efficiency of 92%. If electricity costs $0.10/kWh and the motor runs 6,000 hours/year, approximately what is the annual electricity cost? (1 hp = 0.746 kW)$34,000$41,400$38,000$46,500

Question 111During a compressed-air audit you find the system operates at 110 psig, but the highest end-use only needs 80 psig. As a rule of thumb, reducing system pressure by roughly 2 psi saves about 1% of compressor energy. What is the most defensible first recommendation?Replace the compressor with a larger unit to handle peaksLower system pressure toward the minimum required by end uses and address the one high-pressure application locallyAdd a desiccant dryer to improve air qualityIncrease pressure to 125 psig to create more storage

Question 112An auditor measures a 3-phase motor with line voltages of 480, 475, and 466 V. What is the percent voltage unbalance, and why does it matter?About 1.6%; unbalance causes disproportionately higher winding losses and heatingAbout 3.0%; it improves power factorAbout 0.5%; it has no measurable effectAbout 6.0%; it increases motor efficiency

Question 113A facility has a measured power factor of 0.78 lagging and is billed a reactive power penalty. The most cost-effective correction measure for a steady inductive load is usually:Installing fixed shunt capacitor banks sized to the reactive demandIncreasing supply voltageAdding more inductive load to balance the systemReplacing all wiring with larger conductors

Question 114When estimating savings from replacing a standard-efficiency motor with a premium-efficiency motor, the most important factor that determines whether the replacement is economic is:The motor's nameplate colorAnnual operating hours combined with motor loadingThe physical weight of the motorThe color of the surrounding switchgear

Question 115An ultrasonic leak detector identifies a 1/8-inch (≈3 mm) compressed-air leak at 100 psig. Such a leak can waste on the order of 25–30 CFM. Why are compressed-air leaks considered a high-priority ECM?They improve dew point in the distribution systemCompressed air is one of the most expensive utilities per unit of delivered energy, and leaks run continuouslyLeaks reduce compressor cycling and extend equipment lifeLeaks lower the system pressure to the optimal setpoint

Question 116A plant has multiple 460 V motors driving constant-flow pumps that are throttled by control valves. The single most impactful electrical/motor ECM an auditor would typically propose is:Installing variable frequency drives (VFDs) on the variable-load pumpsAdding more throttling valves downstreamRewinding all the motorsIncreasing the pump impeller diameter

Question 117According to affinity laws for a centrifugal fan/pump driven by a VFD, if speed is reduced to 80% of full speed, the shaft power demand becomes approximately:80% of full power64% of full power51% of full power90% of full power

Question 118An auditor wants to determine the actual load on an in-service induction motor without disconnecting it. The most accurate practical field method is:Reading the nameplate horsepower and assuming full loadMeasuring input kW with a power meter and comparing to rated input, or using the slip methodEstimating from the motor's physical sizeMeasuring only the voltage across two phases

Question 119A compressed-air system uses a single large compressor that modulates inlet throttling to match part-load demand. Compared with load/unload or VSD control, inlet modulation at part load is:The most energy-efficient control strategyTypically the least efficient because power stays high even at low outputIdentical in efficiency to VSD controlOnly used on reciprocating compressors

Question 120When auditing motor systems, the practice of "rewinding vs. replacing" matters because each rewind of a motor can:Increase efficiency by 2–3 percentage pointsSlightly reduce efficiency (often ~0.5–1 point) if done poorly, eroding lifetime savingsHave no effect on efficiency at allDouble the motor's rated horsepower

Question 121An auditor reviews a facility's interval (demand) data and notices a sharp 15-minute peak each morning when several large motors start simultaneously. The best demand-reduction measure is most likely:Staggering equipment start-up sequencing (load shedding/scheduling)Increasing all motor sizesRemoving all soft startersSwitching to higher supply voltage

Question 122A 50 hp compressor produces 200 CFM at full load. An audit finds that during the third (night) shift, demand drops to about 40 CFM but the compressor still runs fully loaded due to poor control. The best low-cost recommendation is:Install a smaller trim/lead compressor or proper sequencing controls to match night loadAdd a second 50 hp compressor for redundancyRaise system pressure during the night shiftOpen additional drains to keep the compressor loaded

Question 123Using compressed air for tasks such as personnel cooling, open blow-off, or sweeping floors is discouraged in audits primarily because:It is an extremely inefficient and costly way to deliver moving air; alternatives like fans or blowers are far cheaperCompressed air is too cold for personnel coolingIt raises the system dew point excessivelyIt violates voltage unbalance limits

Question 124An auditor estimates compressed-air leak load by running the compressor in load/unload mode during no-production time. The leak fraction is calculated as Load time / (Load + Unload time). If load = 4 min and unload = 16 min over a cycle, the leak load is approximately what fraction of compressor capacity?About 50%About 20%About 80%About 5%

Question 125A motor is significantly oversized, operating at only 35% load. From an efficiency standpoint, the main concern at this loading is:Efficiency and power factor both drop noticeably below about 40–50% loadEfficiency rises continuously as load decreasesPower factor improves at light loadThere is no efficiency impact below full load

Question 126When auditing a lighting-and-receptacle electrical panel, an auditor uses a true-RMS clamp meter rather than an averaging meter primarily to:Accurately measure current on nonlinear loads with harmonics (e.g., electronic ballasts, drives)Measure DC voltage onlyAvoid having to open the panelReduce the measured power factor

Question 127Heat recovery from an air compressor is attractive because as much as 80–90% of the electrical energy input to the compressor is converted to:Useful compressed-air energy delivered to end usesRecoverable heat (in the cooling air or water), which can be reused for space or process heatingMechanical vibration energyStored potential energy in the receiver tank

Question 128An auditor finds a 200 hp motor that has been rewound three times and runs 8,000 hr/yr near full load. The most economically sound recommendation is usually:Rewind it a fourth time to save capital costReplace it with a NEMA Premium efficiency motor, given the high run hours and accumulated efficiency lossDownsize it to a 100 hp motor regardless of loadLeave it as is and monitor only

Question 129A facility's compressed-air storage is undersized, causing the compressor to short-cycle. Adding properly sized receiver capacity primarily helps by:Increasing the dew point of the delivered airStabilizing pressure and reducing rapid load/unload cycling, lowering energy use and wearPermanently increasing total system CFM capacityEliminating the need for any compressor controls

Question 130An auditor calculates that a proposed VFD on a 75 hp supply fan will save $9,000/year and costs $18,000 installed. Ignoring escalation and discounting, the simple payback period is:1 year2 years4 years0.5 year

Final check — CEA — Certified Energy Auditor (Exam-Prep)

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