Certified Energy Auditor Certification Data Collection and Analysis 4 — Questions and Answers
Question 1: An auditor collects monthly gas consumption data for a hospital and notices an anomaly in July showing a 40% spike. What is the most logical first investigative step?
- Check for a billing error or meter read anomaly in the utility data (Correct answer)
- Assume the boiler plant is the cause and schedule a tune-up
- Dismiss the spike as a seasonal pattern
- Replace the gas meter immediately
Correct answer: Check for a billing error or meter read anomaly in the utility data
Utility billing anomalies are commonly caused by estimated reads, billing errors, or single-month meter corrections that should be verified before drawing conclusions.
Question 2: What is the significance of the 'occupied' vs. 'unoccupied' energy split when analyzing interval meter data?
- It reveals whether HVAC and lighting controls are functioning correctly during setback periods (Correct answer)
- It determines the building's peak demand charge for utility billing
- It calculates the thermal mass coefficient of the building envelope
- It identifies the correct depreciation schedule for equipment
Correct answer: It reveals whether HVAC and lighting controls are functioning correctly during setback periods
Comparing occupied and unoccupied energy draws exposes control failures such as HVAC running at full load overnight.
Question 3: A combustion analysis of a natural gas boiler shows 14% excess air. What does this indicate compared to a reading of 50% excess air?
- 14% excess air is near optimal; 50% excess air wastes fuel through stack heat loss (Correct answer)
- 50% excess air is safer and always preferred for complete combustion
- Both readings indicate the same efficiency level
- 14% excess air means the boiler is operating dangerously fuel-rich
Correct answer: 14% excess air is near optimal; 50% excess air wastes fuel through stack heat loss
Optimal excess air for natural gas combustion is roughly 10–15%; higher excess air increases flue gas losses and reduces efficiency.
Question 4: Which measurement technique is used to assess thermal bridging in a building envelope without destructive testing?
- Infrared thermography during a temperature differential condition (Correct answer)
- Blower door test with smoke pencil
- Core sample extraction and lab analysis
- Ultrasonic thickness gauge
Correct answer: Infrared thermography during a temperature differential condition
Infrared cameras reveal surface temperature differences that indicate conductive heat paths (thermal bridges) through the envelope.
Question 5: When an energy auditor calculates a facility's load factor, what does a low load factor (e.g., 40%) imply?
- Peak demand is high relative to average demand, indicating potential for demand charge reduction (Correct answer)
- The facility runs at near-constant full load and billing is efficient
- Lighting controls are functioning optimally
- The facility has low overall energy intensity
Correct answer: Peak demand is high relative to average demand, indicating potential for demand charge reduction
A low load factor means peak demand is much higher than the average, creating demand charge exposure that may be reducible through load shifting or peak shaving.
Question 6: During data collection for a refrigeration system audit, the auditor records suction pressure, discharge pressure, and superheat. What is the primary analytical use of superheat measurement?
- Determine whether the refrigerant charge and metering device are operating correctly (Correct answer)
- Calculate the coefficient of performance (COP) of the compressor
- Measure condenser heat rejection capacity
- Verify insulation thickness on suction lines
Correct answer: Determine whether the refrigerant charge and metering device are operating correctly
Superheat indicates how much the refrigerant vapor has been heated above saturation temperature, which reveals whether the system is correctly charged and the expansion valve is properly set.
Question 7: A facility manager provides three years of utility bills but admits meter reads were estimated for four months. How should the auditor handle this in the analysis?
- Flag the estimated months, use weather-normalized averages to fill gaps, and note the limitation in the report (Correct answer)
- Exclude all three years and require new utility data
- Accept the data as-is since four months is a small fraction
- Use only the months with actual reads and extrapolate from those alone
Correct answer: Flag the estimated months, use weather-normalized averages to fill gaps, and note the limitation in the report
Auditors should document data quality issues, use normalization techniques to fill gaps, and disclose limitations so recommendations are not overstated.
Certified Energy Auditor Certification Data Collection and Analysis 4
An auditor collects monthly gas consumption data for a hospital and notices an anomaly in July showing a 40% spike.
What is the most logical first investigative step?