CEM Certified Energy Manager Audit & Billing 5 — Questions and Answers
Question 1: When auditing a steam system, a CEM uses an ultrasonic leak detector and identifies multiple steam trap failures. Failed-open traps primarily cause:
- Water hammer events
- Continuous steam blowthrough and wasted fuel (Correct answer)
- Reduced steam pressure to end users
- Condensate flooding in the return lines
Correct answer: Continuous steam blowthrough and wasted fuel
A steam trap that fails open allows live steam to pass continuously into the condensate return system, directly wasting fuel.
Question 2: Which energy audit deliverable documents the scope of work, audit boundaries, and data collection methodology agreed upon before fieldwork begins?
- Audit final report
- Energy Conservation Measure (ECM) list
- Audit work plan or scope of work document (Correct answer)
- Measurement and Verification plan
Correct answer: Audit work plan or scope of work document
The audit work plan or scope of work document defines boundaries, objectives, and methods before the auditor begins data collection.
Question 3: A CEM is reviewing a compressed air system and finds the system operates at 120 psi but end-use equipment only requires 90 psi. Reducing system pressure to 95 psi would primarily:
- Increase compressor run time
- Reduce compressor energy consumption and leakage losses (Correct answer)
- Increase air receiver tank cycling
- Decrease air quality for critical applications
Correct answer: Reduce compressor energy consumption and leakage losses
Reducing compressed air system pressure lowers compressor power consumption and reduces air leakage rates, which are pressure-dependent.
Question 4: On a utility bill, the 'fuel adjustment clause' or 'fuel cost adjustment' represents:
- A fixed monthly charge for fuel infrastructure
- A variable charge that passes fuel cost fluctuations to customers (Correct answer)
- A penalty for high fuel consumption
- A rebate for using renewable energy
Correct answer: A variable charge that passes fuel cost fluctuations to customers
Fuel adjustment clauses allow utilities to pass variable fuel procurement costs directly to customers, adjusting monthly as fuel prices change.
Question 5: During an ASHRAE Level II audit, which of the following is typically NOT included?
- Identification of ECMs with order-of-magnitude cost estimates
- Detailed engineering calculations for each ECM (Correct answer)
- Energy use benchmarking against similar facilities
- Review of utility bills for at least 12 months
Correct answer: Detailed engineering calculations for each ECM
Detailed engineering calculations for each ECM are characteristic of a Level III audit, not Level II, which uses estimates rather than rigorous engineering analysis.
Question 6: A CEM calculates an Internal Rate of Return (IRR) of 22% for an energy project. This means:
- The project pays back in 22 months
- The project's discount rate at which NPV equals zero is 22% (Correct answer)
- Annual energy savings equal 22% of installation cost
- The project exceeds its simple payback by 22%
Correct answer: The project's discount rate at which NPV equals zero is 22%
IRR is the discount rate that makes the net present value of all cash flows equal to zero; a 22% IRR is typically considered attractive for energy projects.
Question 7: When evaluating electricity bills for demand charge reduction opportunities, which interval data granularity provides the MOST actionable insight?
- Annual consumption totals
- Monthly peak demand values
- 15-minute interval demand data (Correct answer)
- Daily energy totals
Correct answer: 15-minute interval demand data
15-minute interval data reveals the exact timing and duration of demand spikes, enabling targeted load control strategies.
CEM Certified Energy Manager Audit & Billing 5
When auditing a steam system, a CEM uses an ultrasonic leak detector and identifies multiple steam trap failures.
Failed-open traps primarily cause: