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 facility's boiler stack temperature has increased by 50°F over the past year with no change in load. What is the most probable cause?
Answer: Fouled heat transfer surfaces (soot or scale) reducing heat absorption
Fouled boiler tubes act as insulators, preventing heat transfer to the water/steam and allowing more heat to escape up the stack, raising flue gas temperature and reducing efficiency.
In a retro-commissioning (RCx) project, what distinguishes it from a standard energy audit?
Answer: RCx identifies and corrects operational deficiencies in existing systems without major capital investment
Retro-commissioning systematically investigates and corrects how existing building systems are operating—such as control sequences, scheduling, and setpoints—typically with low-cost operational improvements.
Which federal program provides a voluntary energy performance certification specifically for industrial manufacturing plants in the US?
Answer: ENERGY STAR for Industry / Superior Energy Performance (SEP)
The Superior Energy Performance (SEP) program, aligned with ISO 50001, offers third-party certified recognition for industrial facilities that demonstrate measured energy performance improvements.
What is the primary purpose of 'submetering' in a large commercial facility?
Answer: To measure energy consumption at the system or tenant level for accountability and targeting of savings
Submetering breaks total facility consumption into component parts (by floor, tenant, or system), enabling identification of energy waste, tenant billing, and targeting of conservation measures.
A rooftop photovoltaic (PV) array generates AC power that exceeds the facility's instantaneous load. What happens under a net metering agreement?
Answer: Excess generation is exported to the grid and credited against future utility bills
Under net metering, excess PV generation flows back to the grid and the facility receives a credit (typically at retail rate) that offsets future electricity charges.
Which of the following best describes the 'greenhouse gas (GHG) Scope 2' emissions category relevant to facility energy management?
Answer: Indirect emissions from purchased electricity, steam, heat, or cooling consumed by the facility
Scope 2 covers indirect GHG emissions associated with purchased energy—electricity, district heating/cooling, or steam—that is generated off-site but consumed by the reporting organization.
A facilities engineer is sizing a replacement chiller and considers the Integrated Part Load Value (IPLV). Why is IPLV more useful than the full-load COP for this application?
Answer: Most commercial chillers operate at partial load the majority of the time, making IPLV more representative of real-world efficiency
Commercial chillers rarely operate at full load; IPLV weights efficiency at 25%, 50%, 75%, and 100% load conditions to better represent annual energy consumption under typical operating profiles.