EMP Remediation & Mitigation Strategies 3 — Questions and Answers
Question 1: A facility manager wants to reduce demand charges by mitigating peak load. Which strategy uses load shifting rather than load shedding?
- Curtailing HVAC operation during peak demand windows
- Pre-cooling the building before peak rate periods begin (Correct answer)
- Turning off non-essential lighting during peak hours
- Reducing chiller setpoints to reduce run time
Correct answer: Pre-cooling the building before peak rate periods begin
Pre-cooling shifts the cooling load to off-peak hours using the building's thermal mass, avoiding demand charges without curtailing comfort.
Question 2: Which remediation action most directly addresses motor system over-sizing, a common source of industrial energy waste?
- Installing power factor correction capacitors
- Right-sizing motors during scheduled replacement or adding a VFD to reduce effective load (Correct answer)
- Lubricating motor bearings on a quarterly schedule
- Increasing motor voltage to improve efficiency
Correct answer: Right-sizing motors during scheduled replacement or adding a VFD to reduce effective load
Right-sizing eliminates the efficiency penalty of operating motors at low load, and VFDs allow speed reduction to match actual load requirements.
Question 3: An energy audit identifies that a facility's steam traps have a 25% failure rate. What is the primary energy impact of failed-open steam traps?
- Increased boiler cycling and reduced thermal output
- Live steam blowing directly to the condensate return, wasting latent heat (Correct answer)
- Water hammer and pipe erosion reducing system life
- Reduced steam pressure causing process temperature drops
Correct answer: Live steam blowing directly to the condensate return, wasting latent heat
Failed-open traps pass live steam into the condensate system, wasting the latent heat of vaporization that represents the bulk of steam's energy content.
Question 4: A grocery store's refrigeration system shows high discharge superheat. Which mitigation measure addresses this root cause?
- Adding a suction line accumulator to prevent liquid slugging
- Cleaning evaporator coils and checking expansion valve superheat setpoint (Correct answer)
- Increasing condenser fan speed to lower head pressure
- Installing a liquid line filter-drier to remove moisture
Correct answer: Cleaning evaporator coils and checking expansion valve superheat setpoint
Dirty evaporator coils reduce heat transfer and can cause improper expansion valve operation, both of which elevate discharge superheat and reduce system efficiency.
Question 5: Which mitigation measure best addresses lighting energy waste caused by daylight availability in a perimeter office zone?
- Replacing T8 fluorescent lamps with T5 high-output lamps
- Installing photosensor-based dimming controls linked to luminaires in the daylit zone (Correct answer)
- Adding occupancy sensors to all perimeter offices
- Painting interior walls a lighter color to improve reflectance
Correct answer: Installing photosensor-based dimming controls linked to luminaires in the daylit zone
Photosensor dimming continuously modulates electric light output in response to available daylight, capturing daylighting savings automatically throughout the day.
Question 6: A boiler stack analysis shows 15% excess air and 400°F flue gas temperature. Which remediation measure has the highest energy savings potential?
- Installing an economizer to preheat combustion air or feedwater (Correct answer)
- Reducing excess air to the minimum safe level via combustion tuning
- Switching from natural gas to propane fuel
- Adding a flame safeguard controller to improve ignition reliability
Correct answer: Installing an economizer to preheat combustion air or feedwater
At 400°F stack temperature, an economizer recovering heat from flue gases provides the greatest absolute energy recovery, though combustion tuning should accompany it.
Question 7: Which approach is the correct sequence for applying the energy efficiency hierarchy when remediating a facility?
- Upgrade equipment first, then optimize operations, then eliminate waste
- Eliminate waste first, then optimize operations, then upgrade equipment (Correct answer)
- Install renewable energy first to offset remaining consumption
- Improve metering and monitoring before any physical changes
Correct answer: Eliminate waste first, then optimize operations, then upgrade equipment
The efficiency hierarchy prioritizes eliminating waste (behavior/scheduling), then operational optimization, then capital upgrades to avoid over-sizing efficient equipment for wasteful loads.
EMP Remediation & Mitigation Strategies 3
A facility manager wants to reduce demand charges by mitigating peak load.
Which strategy uses load shifting rather than load shedding?