CEA common mistakes
CEA · Understand the traps and how to avoid them.
Building the audit scope around equipment nameplate counts and a walkthrough alone, then presenting savings without first defining the audit level (ASME Level 1/2/3 or equivalent), the measurement boundary, and the baseline period in a written plan.
Candidates treat the strategy-and-plan phase as paperwork and jump straight to calculations. The exam weights planning heavily, and a missing baseline or boundary makes every downstream savings number indefensible, so scorers can award little partial credit.
What to do instead
Before any field work, draft a one-page plan that states audit level, system boundary, baseline period and normalization method (weather, production, occupancy), data quality objectives, and deliverables. Practice writing this for three hypothetical facilities so the structure becomes automatic.
Reporting a single blended energy use intensity for the whole building and skipping the end-use breakdown (lighting, HVAC, DHW, plug, process, compressed air) that would reveal where savings actually live.
Utility bills are easy to obtain and candidates anchor on them. Without sub-metering or engineering estimates by end use, the candidate cannot prioritize measures, and the exam expects a defensible allocation.
What to do instead
Build a top-down/bottom-up reconciliation: allocate annual consumption by end use using inventory-based estimates, then compare the total to utility data and explain the gap. Show the allocation table and the reconciliation residual in every energy use analysis answer.
Presenting savings and payback from a single point estimate without stating assumptions, data sources, or a sensitivity range, and ignoring interactive effects between measures.
Candidates want a clean number and worry that ranges look indecisive. In practice, reviewers and the exam both penalize unstated assumptions and double-counted savings.
What to do instead
For each measure, list inputs with source and uncertainty, compute low/base/high savings, and explicitly adjust for interactive effects (for example lighting heat gain reducing cooling load). Present simple payback alongside life-cycle cost or net present value.
Spot-reading illuminance once at desk height and declaring lighting compliant or deficient, without documenting measurement grid, sensor calibration, time of day, daylight contribution, or maintained vs initial levels.
Handheld meter readings feel objective, and candidates skip the protocol. The exam tests whether the candidate understands that a single reading cannot support a compliance or retrofit recommendation.
What to do instead
Specify a grid spacing (commonly about one point per grid cell based on room index), record sensor model and calibration date, note daylight and occupancy conditions, and compare to the target maintained illuminance with a light-loss factor for the chosen luminaire.
Estimating HVAC savings by applying a flat percentage to the whole HVAC bill rather than calculating load change from the specific measure (setback, economizer, VFD, ventilation reduction) using bin or degree-day methods.
Full load calculations are time-consuming and candidates default to rules of thumb. The exam distinguishes between a screening estimate and an engineering calculation and rewards the latter when the question asks for savings.
What to do instead
Practice bin-hour or degree-day calculations for a few representative measures. Show the load equation, operating hours, part-load behavior, and equipment efficiency so the savings chain is traceable from measure to kWh or therms.
Treating domestic hot water as a fixed load and recommending only pipe insulation, while omitting storage losses, recirculation loop losses, temperature setpoint, and fixture flow reductions from the analysis.
DHW is a small share of total energy at many facilities, so candidates under-invest. Exam questions often probe the recirculation and storage loss components that dominate DHW energy.
What to do instead
Compute DHW load from fixture demand and occupancy, then separately estimate storage standby loss and recirculation loss. Evaluate setpoint reduction, pipe and tank insulation, low-flow fixtures, and heat recovery as distinct measures with their own savings.
Recommending a VFD for every motor and a pressure reduction for every compressed air system without checking load profile, duty cycle, motor oversizing, harmonics, or the minimum acceptable end-use pressure.
VFDs and pressure reduction are memorable, high-profile measures, and candidates apply them as templates. The exam tests whether the candidate can identify when a measure is technically inappropriate.
What to do instead
For each motor, document load factor, hours, and variability before recommending a drive; for compressed air, measure actual system pressure at the farthest end use and confirm the lowest required pressure. State the conditions under which the measure would not apply.
Describing envelope improvements qualitatively ("add insulation", "seal leaks") without quantifying conductance, infiltration, or thermal bridging, and without accounting for the interaction with HVAC sizing and moisture risk.
Envelope work is hard to meter and candidates avoid the numbers. The exam expects heat-loss calculations and awareness that tightening a building can change ventilation and moisture behavior.
What to do instead
Calculate U-values for existing and proposed assemblies, estimate infiltration with an air-change or blower-door basis, and quantify conduction and infiltration savings separately. Note moisture and ventilation implications of air sealing.
Recommending BAS/EMCS sequences and controls upgrades without documenting the existing point list, trend data availability, or a measurement and verification plan for the resulting savings.
Controls savings are invisible and depend on commissioning, so candidates assert them without evidence. The exam rewards candidates who tie controls measures to trend data and M&V.
What to do instead
Describe the existing control sequence and point schedule, specify the proposed sequence in plain language, and define the trend points and baseline period that will verify savings. Include a retro-commissioning step and an M&V option (for example IPMVP Option B or C).
Proposing on-site generation or storage (solar PV, CHP, batteries) as a savings measure without separating avoided energy cost, demand charge reduction, and capital cost treatment, and without checking load matching and interconnection constraints.
Renewables and storage are attractive and candidates fold them into efficiency savings, which conflates two different economic analyses and overstates the efficiency case.
What to do instead
Analyze generation and storage as a supply-side option with its own hourly load match, tariff treatment, incentive and tax assumptions, and life-cycle cost. Keep it separate from demand-side efficiency measures in the report and in any payback comparison.