Energy and Utilities Energy Efficiency and Conservation 1 — Questions and Answers
Question 1: What does ENERGY STAR certification on an appliance indicate?
- The appliance was manufactured in the US
- The appliance meets EPA energy efficiency standards, using significantly less energy than standard models (Correct answer)
- The appliance uses only renewable electricity
- The appliance has no standby power draw
Correct answer: The appliance meets EPA energy efficiency standards, using significantly less energy than standard models
ENERGY STAR is a joint EPA/DOE program that certifies products meeting specific energy efficiency criteria, typically 10–50% more efficient than minimum standards.
Question 2: What is 'phantom load' or 'vampire power'?
- Power lost in transmission lines
- Electricity consumed by devices while in standby or turned off (Correct answer)
- Surge power during equipment startup
- Power factor losses in motors
Correct answer: Electricity consumed by devices while in standby or turned off
Phantom load is the electricity continuously drawn by electronics and appliances when plugged in but not actively in use.
Question 3: What does 'R-value' measure in building insulation?
- The reflectivity of roofing materials
- Thermal resistance — how well insulation resists heat flow (Correct answer)
- The recycled content percentage of insulation
- The fire resistance rating of wall materials
Correct answer: Thermal resistance — how well insulation resists heat flow
R-value is a measure of thermal resistance; higher R-values indicate better insulating performance and less heat transfer through the material.
Question 4: What is a 'demand charge' on a commercial electric utility bill?
- A charge based on total monthly energy consumption
- A charge based on the customer's peak power demand during the billing period (Correct answer)
- A fee for requesting new service
- A surcharge for renewable energy programs
Correct answer: A charge based on the customer's peak power demand during the billing period
Demand charges are billed based on a customer's highest measured power draw (kW) during the billing period, covering the utility's cost to keep capacity available.
Question 5: What is a 'heat pump' and why is it considered energy efficient?
- A furnace that burns natural gas very efficiently
- A device that moves heat rather than generating it, providing 2–4 units of heating/cooling per unit of electricity (Correct answer)
- A pump that transfers heated water for radiant floor heating
- A solar thermal device that heats water
Correct answer: A device that moves heat rather than generating it, providing 2–4 units of heating/cooling per unit of electricity
Heat pumps move thermal energy from one place to another using refrigerant cycles, achieving efficiencies (COP) of 2–4, far exceeding the 1.0 limit of resistive heating.
Question 6: What is the purpose of an energy audit for a commercial building?
- Verifying the accuracy of electric meters
- Systematically identifying opportunities to reduce energy consumption and costs (Correct answer)
- Checking compliance with electrical code
- Auditing energy suppliers' billing practices
Correct answer: Systematically identifying opportunities to reduce energy consumption and costs
An energy audit analyzes a building's energy use patterns and systems to identify cost-effective efficiency improvements and reduce operating costs.
Energy and Utilities Energy Efficiency and Conservation 1
What does ENERGY STAR certification on an appliance indicate?