Certified Energy Auditor Certification Energy Audit Process 5 — Questions and Answers
Question 1: An energy auditor reviews a facility's demand charges and finds they represent 40% of the total electric bill. What strategy should be prioritized?
- Reduce overall annual kWh consumption only
- Implement peak demand management through load shifting and demand response (Correct answer)
- Replace all fluorescent lamps with LEDs immediately
- Increase building insulation levels
Correct answer: Implement peak demand management through load shifting and demand response
When demand charges are a large portion of utility costs, strategies that flatten peak demand — such as load shifting, storage, and demand response — provide the greatest bill savings.
Question 2: What is the primary function of an energy model calibration during a detailed (Level III) energy audit?
- To certify the building for LEED documentation
- To tune the simulation model so it matches actual measured utility data within accepted tolerances (Correct answer)
- To calculate equipment depreciation schedules
- To generate automatic permit applications
Correct answer: To tune the simulation model so it matches actual measured utility data within accepted tolerances
Calibration adjusts model inputs until simulated energy use matches actual utility data (ASHRAE Guideline 14 requires ±15% NMBE and ±30% CV(RMSE)), ensuring reliable ECM savings predictions.
Question 3: Which parameter does a duct pressurization test (duct blaster) specifically measure?
- Supply air temperature at registers
- Airflow leakage from the duct system at a standardized pressure (Correct answer)
- Static pressure drop across filters
- Duct insulation R-value
Correct answer: Airflow leakage from the duct system at a standardized pressure
A duct blaster pressurizes the duct system to 25 Pa and measures the airflow required to maintain that pressure, quantifying total duct leakage in CFM25.
Question 4: An auditor identifies that a compressed air system has a system pressure of 120 psi, but end uses only require 90 psi. What ECM should be recommended?
- Install a larger air compressor
- Reduce system operating pressure to match actual end-use requirements (Correct answer)
- Add desiccant dryers to all branch lines
- Replace copper piping with stainless steel
Correct answer: Reduce system operating pressure to match actual end-use requirements
Compressor power increases with discharge pressure; reducing system pressure by 10 psi typically saves approximately 5% in compressor energy, so matching pressure to actual needs yields significant savings.
Question 5: During an audit, an auditor finds that the building automation system (BAS) setback schedule is not functioning and the building is conditioned to occupied setpoints 24/7. Which action provides the most direct immediate energy savings recommendation?
- Replace the entire BAS with a new system
- Repair or reprogram the BAS to implement nighttime and weekend temperature setbacks (Correct answer)
- Add rooftop solar panels to offset overnight consumption
- Install occupancy sensors in all restrooms
Correct answer: Repair or reprogram the BAS to implement nighttime and weekend temperature setbacks
Restoring HVAC setback schedules during unoccupied periods is a no/low-cost operational measure that can reduce heating and cooling energy by 10–25% with immediate effect.
Question 6: What is the significance of a building's 'plug load' in the energy audit process?
- It refers only to electrical outlets in server rooms
- It represents the energy consumed by all equipment plugged into electrical outlets, which can be a major uncontrolled end-use (Correct answer)
- It measures the pressure drop across plumbing fixtures
- It defines the building's peak electrical demand from lighting only
Correct answer: It represents the energy consumed by all equipment plugged into electrical outlets, which can be a major uncontrolled end-use
Plug loads from computers, monitors, appliances, and miscellaneous equipment often account for 20–50% of commercial building energy use and are a key audit target for behavioral and equipment ECMs.
Question 7: An energy auditor is evaluating a chilled water system and finds the delta-T across the evaporator is only 4°F instead of the design 10°F. What does this low delta-T syndrome indicate?
- The chiller is operating at peak efficiency
- Excessive chilled water flow rate reducing the temperature differential and increasing pump energy (Correct answer)
- The cooling tower is undersized
- Supply air setpoints are too high
Correct answer: Excessive chilled water flow rate reducing the temperature differential and increasing pump energy
Low delta-T syndrome means chillers must run longer, more chillers stage on unnecessarily, and chilled water pumps operate at higher-than-needed flow rates, all increasing system energy consumption.
Certified Energy Auditor Certification Energy Audit Process 5
An energy auditor reviews a facility's demand charges and finds they represent 40% of the total electric bill.
What strategy should be prioritized?