Practice Test Geeks(EMP) Energy Management Professional Practice Test
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Energy Efficiency & Conservation Techniques Flashcards

7 cards from real EMP 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 Efficiency & Conservation Techniques flashcards as text

  1. A commercial building has a high plug load density from workstations. Which strategy MOST effectively reduces plug load energy without impacting occupant productivity?

    Answer: Deploying smart power strips and enabling PC power management settings

    Smart power strips eliminate phantom loads by cutting power to peripherals when master devices are off, while PC power management reduces idle consumption.

  2. What is the significance of the 'affinity laws' in energy management for centrifugal fans and pumps?

    Answer: They show that power consumption varies with the cube of rotational speed, so small speed reductions yield large energy savings

    The affinity laws state that power varies with the cube of speed, meaning a 20% speed reduction results in approximately 49% less power consumption.

  3. An energy manager evaluates adding roof insulation to a commercial building in Chicago. Which performance metric BEST determines the optimal insulation level?

    Answer: The point where the marginal cost of additional insulation equals the marginal energy cost savings (cost-optimal R-value)

    The cost-optimal R-value is found where adding more insulation costs more than the energy it would save, representing the economically ideal level.

  4. A manufacturing plant uses waste heat from exhaust streams to preheat process water via a heat exchanger. This recovered heat reduces boiler fuel consumption by 18%. What term describes this practice?

    Answer: Heat integration or waste heat recovery

    Heat integration or waste heat recovery captures thermal energy from process exhausts to satisfy other thermal demands, reducing primary fuel consumption.

  5. Which ENERGY STAR Portfolio Manager metric is used to benchmark a building's overall energy performance against similar buildings nationally?

    Answer: ENERGY STAR Score (1–100 scale)

    The ENERGY STAR Score ranks a building from 1–100 against similar buildings; a score of 75 or above qualifies for ENERGY STAR certification.

  6. An energy manager discovers that a chilled water plant's delta-T (supply/return temperature difference) has decreased from a design value of 12°F to 4°F. What is the PRIMARY consequence of this 'low delta-T syndrome'?

    Answer: Pumps must circulate much more water to deliver the same cooling, significantly increasing pump energy

    Low delta-T syndrome forces pumps to move 2–3 times more chilled water to deliver the same cooling load, dramatically increasing pump energy consumption.

  7. A large retail store installs night covers on open refrigerated display cases. Beyond food safety benefits, what energy impact is achieved?

    Answer: Night covers reduce refrigeration energy by 30–40% during closed hours by limiting heat and moisture infiltration

    Night covers significantly reduce the refrigeration load by blocking warm, moist store air from entering the display case during non-selling hours.