Energy Management & Sustainability Flashcards
7 cards from real AFE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Energy Management & Sustainability flashcards as text
A facilities engineer wants to benchmark a building's energy performance. Which metric is most commonly used for this purpose in the US?
Answer: Energy Use Intensity (EUI)
Energy Use Intensity (EUI) measures energy consumption per square foot per year and is the standard US benchmarking metric used by ENERGY STAR Portfolio Manager.
Which of the following best describes a 'demand charge' on a commercial utility bill?
Answer: A charge based on the highest 15- or 30-minute peak power demand recorded
Demand charges are billed based on the peak power draw (kW) recorded during the billing period, typically measured in 15- or 30-minute intervals.
In an HVAC system, what does the term 'economizer cycle' refer to?
Answer: Using outdoor air for free cooling when conditions allow
An economizer cycle uses cool outdoor air to provide free cooling to the building, reducing or eliminating mechanical refrigeration when outdoor conditions are favorable.
A facility manager is evaluating two lighting retrofit options. Option A has a simple payback of 2 years; Option B has a simple payback of 4 years but a higher NPV over 10 years. Which statement is most accurate?
Answer: Option B may be the better long-term investment despite the longer payback
Simple payback ignores the time value of money and post-payback savings, so a higher NPV over the project life makes Option B potentially superior for long-term financial performance.
What is the primary purpose of an energy audit's 'baseline' energy model?
Answer: To establish current energy consumption patterns for comparing ECM savings
The baseline model represents existing energy use so that the projected savings from energy conservation measures (ECMs) can be calculated as a measurable difference.
Which refrigerant property makes R-410A unsuitable as a long-term drop-in replacement for systems being phased out under the AIM Act?
Answer: Very high global warming potential (GWP) of approximately 2,088
R-410A has a GWP of ~2,088, making it subject to phase-down under the AIM Act, which targets high-GWP HFCs to reduce climate impact.
A compressed air system audit reveals significant pressure drop across the distribution piping. What is the most likely consequence of excessive pressure drop?
Answer: Compressors must run at higher pressure to compensate, increasing energy consumption
Excessive pressure drop forces the compressor to operate at higher discharge pressures to deliver adequate pressure at end-use points, directly increasing energy consumption.