AEE Certified Energy Auditor common mistakes
AEE Certified Energy Auditor · Understand the traps and how to avoid them.
Calculates retrofit savings by subtracting the 12 months of bills after the ECM from the 12 months before it, with no adjustment for weather or production volume, then presents that difference as the project's savings.
Utility bills are the easiest data to obtain and the raw year-over-year difference looks like a savings number, so the candidate skips the normalization step under time pressure on the case-study items.
What to do instead
Build a weather- and production-normalized baseline before comparing: use a change-point (3- or 5-parameter) regression of monthly energy against HDD/CDD or against output, report the model's R-squared and savings uncertainty, and state the baseline period and adjustments explicitly.
Ranks all ECMs by simple payback and recommends only the measures under a fixed cutoff (e.g., 3 years), discarding long-lived measures with lower life-cycle cost, and applies a single blended $/kWh to every measure.
Simple payback is quick to compute and easy to explain, and blended rates are what appears on the bill, so the candidate never reaches discount rate, measure life, escalation, or demand-charge structure.
What to do instead
Compute life-cycle cost or IRR using the client's discount rate and fuel escalation, annualize alternatives with unequal lives, and separate energy savings from demand-charge savings (apply marginal inclining-block and time-of-use rates to the hours in which the load actually falls).
Estimates annual chiller, boiler, or air-handler energy as nameplate full-load kW times equivalent full-load hours, treating the rated EER/COP as constant across the year.
Nameplate data is what is written on the equipment and the candidate has no part-load data in hand, so full-load efficiency gets applied to a part-load duty cycle.
What to do instead
Use part-load performance data (IPLV/NPLV for chillers, part-load curves or manufacturer data for boilers, fan curves and VFD schedules for fans) and run either a bin method or an hourly model; sanity-check the result against the building's billed consumption.
Computes lighting energy and lighting power density from lamp wattage alone, and computes illuminance from initial lamp lumens, without applying ballast factor, ballast input watts, or light-loss factors.
Lamp wattage is the number printed on the lamp box, while ballast factor, ballast losses, and LLD/LLD maintenance factors live in catalog data the candidate may not have pulled.
What to do instead
Use fixture input watts = (lamp watts x number of lamps x ballast factor) + ballast losses, verify against a clamp meter reading on a sample fixture, and apply LLD and LDD when checking maintained illuminance against IES targets.
Applies the affinity cube law, P2 = P1 x (N2/N1)^3, to a pump or fan in a system that has significant static head or minimum static pressure, and reports the resulting savings directly.
The cube law is memorized as 'VFDs save 50% at half speed' and the system curve is rarely available at the time the estimate is made.
What to do instead
First determine the system curve: for purely frictional systems the cube law holds, but with static head use the fan/pump law form that subtracts the static component, and cap savings at the achievable turndown set by the minimum static pressure and the control deadband.
Calculates envelope conduction as area x delta-T divided by the cavity insulation R-value, ignoring framing, sheathing, air films, and thermal bridging, and treats the result as the whole envelope load.
Only the insulation R-value is known with confidence; assembly U-factors require tables or takeoff that the candidate skips.
What to do instead
Use published assembly U-factors (ASHRAE Handbook of Fundamentals tables) or calculate parallel-path U for framing and cavity, include interior/exterior film resistances, and treat infiltration and ventilation as a separate load rather than folding it into conduction.
Accepts BAS trend logs, point schedules, and dashboard kW readings at face value, deriving occupied/unoccupied schedules and equipment run hours directly from them without verifying sensor calibration or point-to-equipment mapping.
Trend data exports look authoritative and are far faster than field logging, so the candidate never checks whether the sensor reads correctly or the schedule reflects actual occupancy.
What to do instead
Spot-verify with a calibrated portable instrument (temperature, CO2, amps), cross-check trended run hours against run-time meters or billed load shapes, and confirm every trended point is correctly mapped to the equipment before using the data in the savings calculation.
Estimates annual PV or other on-site generation output as installed kW times 8760 hours (or times a guessed capacity factor applied without site specifics), and omits inverter clipping, soiling, shading, and degradation.
Nameplate rating is the one firm number available and the candidate treats it as an energy figure.
What to do instead
Use site-specific specific yield (kWh per kW-year) from a validated model or PVWatts-style calculation with tilt, azimuth, shading loss, soiling, inverter efficiency/clipping, and annual degradation; compare with the building's load shape to size the system and compute the offset.
Arrives at the site with no pre-site analysis, no agreed audit level or boundary, and no data request list, then decides scope while walking the building.
The field visit feels like the real work and the candidate wants to 'see it first,' so the planning step in the audit process is compressed to nothing.
What to do instead
Before mobilizing, fix the audit level (ASHRAE Level I/II/III or equivalent) against the client's objective, define the boundary and baseline period, pull and normalize 24-36 months of utility data, and issue a written pre-site data request and walk-through checklist.
Computes domestic hot water energy as gallons per day x 8.34 lb/gal x delta-T only, ignoring recirculation loop losses, storage standby losses, and the difference between rated EF and installed performance.
The gallons-times-delta-T formula is the standard first-pass equation, and standby and distribution losses are not visible in a short walk-through.
What to do instead
Add recirculation and storage losses explicitly (measure or estimate loop length, pipe insulation, and pump runtime), adjust rated EF to installed conditions, and evaluate controls such as demand recirculation, pipe insulation, and temperature reset as separate measures with their own savings.