AFE Energy Management & Sustainability 3 — Questions and Answers
Question 1: Under ASHRAE 90.1, which building system is addressed by the lighting power density (LPD) requirements?
- HVAC system sizing
- Interior and exterior electrical lighting (Correct answer)
- Plug load management for office equipment
- Emergency and exit lighting circuits
Correct answer: Interior and exterior electrical lighting
ASHRAE 90.1 sets maximum lighting power density limits (W/sq ft) for interior and exterior lighting to ensure energy-efficient lighting design.
Question 2: What does a Power Purchase Agreement (PPA) allow a facility to do?
- Purchase electricity generation equipment with deferred payment terms
- Buy electricity generated by a third-party renewable system at a fixed rate without owning the equipment (Correct answer)
- Negotiate lower demand charges directly with the utility
- Sell excess on-site generation back to the grid at retail rates
Correct answer: Buy electricity generated by a third-party renewable system at a fixed rate without owning the equipment
A PPA allows a facility to purchase renewable electricity from a third-party owner/developer at a predetermined rate, avoiding upfront capital costs for generation equipment.
Question 3: In the context of sustainable facilities management, what does 'embodied carbon' refer to?
- Carbon emissions from daily building operations and energy use
- Greenhouse gas emissions associated with material extraction, manufacturing, and construction (Correct answer)
- Carbon stored within the building's structural materials over its lifetime
- CO2 produced by HVAC combustion equipment within the facility
Correct answer: Greenhouse gas emissions associated with material extraction, manufacturing, and construction
Embodied carbon encompasses all GHG emissions from the entire material lifecycle—extraction, processing, manufacturing, transport, and construction—before a building is occupied.
Question 4: A building's chiller plant has a measured COP of 4.5. What does this value indicate?
- The chiller produces 4.5 kW of cooling for every 1 kW of electrical input (Correct answer)
- The chiller operates at 45% of its rated capacity
- The system's peak demand is 4.5 times the nameplate rating
- 4.5 gallons of condenser water are circulated per ton of cooling
Correct answer: The chiller produces 4.5 kW of cooling for every 1 kW of electrical input
COP (Coefficient of Performance) is the ratio of useful cooling output to energy input; a COP of 4.5 means 4.5 units of cooling are delivered per unit of electricity consumed.
Question 5: Which strategy is most effective for reducing a facility's peak electrical demand during summer afternoons?
- Installing occupancy sensors in restrooms
- Pre-cooling the building during morning off-peak hours (thermal mass shifting) (Correct answer)
- Replacing incandescent lamps with LEDs in storage areas
- Adding weather stripping to exterior doors
Correct answer: Pre-cooling the building during morning off-peak hours (thermal mass shifting)
Pre-cooling exploits lower overnight or morning electricity rates and shifts cooling load away from peak demand periods by storing 'coolth' in the building's thermal mass.
Question 6: Which ISO standard provides the framework for establishing an Energy Management System (EnMS)?
- ISO 14001
- ISO 50001 (Correct answer)
- ISO 9001
- ISO 45001
Correct answer: ISO 50001
ISO 50001 specifies requirements for an Energy Management System, providing organizations with a structured framework to improve energy performance, efficiency, and reduce costs.
Question 7: A facilities engineer reviews a steam trap survey and finds that 15% of traps are failed-open. What is the primary energy consequence?
- Increased condensate return temperature reduces boiler efficiency
- Live steam is continuously vented to atmosphere, wasting fuel and boiler capacity (Correct answer)
- System pressure drops below design, requiring boiler firing rate reduction
- Water hammer incidents increase, damaging insulation
Correct answer: Live steam is continuously vented to atmosphere, wasting fuel and boiler capacity
Failed-open steam traps allow live steam to pass through continuously, resulting in direct energy losses as fuel-generated steam is wasted rather than delivering useful heat.
AFE Energy Management & Sustainability 3
Under ASHRAE 90.1, which building system is addressed by the lighting power density (LPD) requirements?