ASHE Sustainability & Energy Efficiency 3 — Questions and Answers
Question 1: Which type of lighting control strategy offers the greatest energy savings in low-occupancy healthcare corridors?
- Scheduled timers
- Occupancy sensors with bi-level switching (Correct answer)
- Dimming ballasts only
- Manual dimmer switches
Correct answer: Occupancy sensors with bi-level switching
Occupancy sensors with bi-level switching reduce light levels to a minimum when no occupants are detected while maintaining required egress illumination levels.
Question 2: A healthcare facility's cooling tower uses drift eliminators. What environmental benefit do drift eliminators primarily provide?
- Reduce water consumption through better heat transfer
- Prevent water droplets containing Legionella from being discharged to the atmosphere (Correct answer)
- Lower the condenser water supply temperature
- Increase the cycles of concentration in the tower basin
Correct answer: Prevent water droplets containing Legionella from being discharged to the atmosphere
Drift eliminators trap entrained water droplets before they exit the cooling tower, reducing both water loss and the risk of Legionella aerosolization.
Question 3: In healthcare, 'plug load management' refers to controlling energy used by:
- Medical gas outlets in patient rooms
- Electrical equipment plugged into standard receptacles (Correct answer)
- Elevator and escalator motors
- Exterior lighting on a timer
Correct answer: Electrical equipment plugged into standard receptacles
Plug loads from computers, monitors, medical devices, and appliances can account for 25–40% of a hospital's electricity use and are managed through smart strips and power management policies.
Question 4: Which water-side economizer strategy can save significant chiller energy in cooler climates?
- Waterside economizer (free cooling) using the cooling tower in winter (Correct answer)
- Adding glycol to the chilled water loop
- Increasing condenser water flow rate
- Reducing chilled water supply temperature setpoint
Correct answer: Waterside economizer (free cooling) using the cooling tower in winter
Waterside economizers use the cooling tower to directly cool chilled water when outdoor temperatures allow, bypassing or unloading the chiller entirely.
Question 5: A hospital's steam system has significant condensate return losses. What is the most direct sustainability impact of poor condensate return?
- Increased chemical treatment costs only
- Wasted energy, treated water, and chemicals since condensate must be replaced with cold makeup water (Correct answer)
- Reduced boiler capacity
- Higher indoor humidity levels
Correct answer: Wasted energy, treated water, and chemicals since condensate must be replaced with cold makeup water
Condensate returned to the boiler is hot, treated, and demineralized water; losing it wastes the energy it contains and requires chemically treating cold replacement water.
Question 6: ENERGY STAR certification for hospitals requires benchmarking energy performance using which tool?
- Green Building Initiative assessment
- ASHRAE Level II energy audit report
- EPA Portfolio Manager (Correct answer)
- DOE EnergyPlus simulation model
Correct answer: EPA Portfolio Manager
EPA Portfolio Manager is the online benchmarking tool used to calculate the ENERGY STAR score and apply for certification for eligible building types including hospitals.
Question 7: What is the sustainability advantage of variable refrigerant flow (VRF) systems in smaller healthcare outpatient facilities?
- Lower first cost than all other system types
- Ability to simultaneously heat and cool different zones with heat recovery (Correct answer)
- Elimination of mechanical ventilation requirements
- Superior infection control compared to chilled water systems
Correct answer: Ability to simultaneously heat and cool different zones with heat recovery
Heat recovery VRF systems transfer heat from zones that need cooling to zones that need heating simultaneously, reducing total energy consumption significantly.
ASHE Sustainability & Energy Efficiency 3
Which type of lighting control strategy offers the greatest energy savings in low-occupancy healthcare corridors?