AFE Energy Management & Sustainability 4 — Questions and Answers
Question 1: What is the primary function of a Building Automation System (BAS) in energy management?
- To provide occupants with real-time utility billing information
- To centrally monitor and control building systems to optimize energy use and comfort (Correct answer)
- To automatically negotiate utility rates based on consumption patterns
- To replace manual maintenance tasks for mechanical equipment
Correct answer: To centrally monitor and control building systems to optimize energy use and comfort
A BAS integrates control of HVAC, lighting, and other building systems, enabling centralized monitoring and automated optimization to reduce energy waste and maintain comfort.
Question 2: In M&V (Measurement & Verification) per IPMVP, what is the purpose of 'Option C: Whole Facility'?
- Measuring energy savings at individual equipment level using sub-meters
- Determining savings by analyzing utility meter data before and after ECM installation (Correct answer)
- Stipulating equipment performance based on manufacturer specifications
- Isolating and measuring a single energy system using a dedicated meter
Correct answer: Determining savings by analyzing utility meter data before and after ECM installation
IPMVP Option C uses whole-facility utility meter data with statistical regression analysis to determine aggregate savings from all ECMs implemented at a site.
Question 3: A cooling tower's 'cycles of concentration' (COC) has dropped from 6 to 3. What is the most likely operational consequence?
- Reduced fan energy consumption due to lower airflow requirements
- Increased makeup water consumption and higher water treatment chemical costs (Correct answer)
- Lower condenser water supply temperature improving chiller efficiency
- Decreased blowdown frequency reducing water disposal costs
Correct answer: Increased makeup water consumption and higher water treatment chemical costs
Lower COC means more frequent blowdown is occurring, requiring more makeup water to replace it, increasing both water consumption and chemical treatment costs.
Question 4: Which of the following is a direct benefit of installing variable frequency drives (VFDs) on centrifugal pump motors?
- Eliminating the need for pressure relief valves in the system
- Reducing motor energy consumption significantly at partial flow conditions using the affinity laws (Correct answer)
- Increasing the motor's service factor to handle higher torque loads
- Extending pump impeller life by increasing rotational speed
Correct answer: Reducing motor energy consumption significantly at partial flow conditions using the affinity laws
The affinity laws state that pump power varies with the cube of speed, so a small reduction in speed yields large energy savings—a 20% speed reduction produces approximately 49% power reduction.
Question 5: What does LEED 'Platinum' certification indicate about a building?
- The building has zero net energy consumption on an annual basis
- The building has achieved the highest tier of LEED green building credits (80+ points) (Correct answer)
- The building meets minimum ASHRAE 90.1 energy code requirements
- The building has received federal government recognition for sustainability
Correct answer: The building has achieved the highest tier of LEED green building credits (80+ points)
LEED Platinum is the highest certification level, awarded when a project earns 80 or more points across all credit categories under the USGBC's LEED rating system.
Question 6: A facility implements an occupancy-based HVAC setback strategy. Which scenario would yield the greatest energy savings?
- A 24/7 call center with constant occupancy year-round
- A single-shift manufacturing plant with no weekend operations (Correct answer)
- A hospital emergency department with variable occupancy
- A data center with constant thermal loads
Correct answer: A single-shift manufacturing plant with no weekend operations
A single-shift manufacturing plant with no weekend operations has the longest unoccupied periods, providing maximum opportunity for HVAC setback and consequently the greatest energy savings.
Question 7: When conducting a Type II energy audit (per ASHRAE Procedures for Commercial Building Energy Audits), what deliverable is expected beyond what a Type I provides?
- Only a utility bill analysis and site walkthrough summary
- Detailed engineering analysis of ECMs with energy, demand, and cost savings calculations (Correct answer)
- A full energy model calibrated to 12 months of utility data
- A retro-commissioning report for all major mechanical systems
Correct answer: Detailed engineering analysis of ECMs with energy, demand, and cost savings calculations
A Type II audit includes detailed engineering calculations for each identified ECM with estimated energy savings, demand savings, implementation costs, and simple payback periods.
AFE Energy Management & Sustainability 4
What is the primary function of a Building Automation System (BAS) in energy management?