Remediation & Mitigation Strategies Flashcards

A facility installs a variable frequency drive on a centrifugal pump and reduces speed by 20%. Approximately how much energy is saved according to the affinity laws?

Answer: 49%

The affinity laws state that power varies with the cube of speed; (0.8)³ = 0.512, so power drops to about 51% of original, saving approximately 49%.

Which remediation strategy is most appropriate for a data center with a PUE of 2.4 where cooling is the dominant energy consumer?

Answer: Implementing hot aisle/cold aisle containment and raising supply air temperature to ASHRAE A1 limits

Containment eliminates air mixing and allows higher supply temperatures, dramatically reducing cooling energy and improving PUE without affecting IT load.

An energy manager is evaluating the retrofit of T12 magnetic ballast fixtures to LED. Which metric best quantifies the lighting quality maintained after the change?

Answer: Maintained illuminance (footcandles) at the work plane verified by measurement

Maintained illuminance measured at the task plane confirms that the new system delivers the required light levels, validating that quality is preserved after the efficiency upgrade.

A facility wants to mitigate water heating energy by recovering heat from a high-volume drain stream. Which technology is best suited for this?

Answer: Drain water heat recovery (DWHR) coil installed on the drain line

DWHR coils wrap around drain pipes and preheat incoming cold water supply using the warmth of draining hot water, recovering energy that would otherwise be lost.

Which mitigation measure most directly reduces transmission losses in an industrial electrical distribution system operating at 480V over long cable runs?

Answer: Stepping up voltage to 4,160V for distribution and stepping down at each load center

Higher distribution voltage reduces current for the same power, and since losses are proportional to I²R, stepping up voltage substantially reduces resistive losses over long runs.

A facility's natural gas bill shows a high gas-to-product ratio compared to the industry benchmark. Which diagnostic step should precede remediation planning?

Answer: Conduct a detailed process energy balance to identify where heat is lost or wasted

A process energy balance quantifies losses at each stage, ensuring that remediation targets the largest opportunities rather than arbitrary equipment upgrades.

Which building automation system (BAS) programming change is a low-cost mitigation for excessive fan energy in a constant-volume air handling unit serving variable occupancy spaces?

Answer: Implementing an occupied/unoccupied schedule to shut down or reduce fan speed during unoccupied hours

Programming occupied/unoccupied schedules into existing BAS controls is a no-cost or low-cost measure that eliminates full-speed fan operation during unoccupied periods.