NABCEP Energy Efficiency & Conservation Techniques 2 — Questions and Answers
Question 1: What does the term 'building envelope' refer to in energy efficiency?
- The HVAC system and ductwork
- The physical barrier between conditioned and unconditioned spaces (Correct answer)
- The electrical distribution panel and wiring
- The plumbing system and water heater
Correct answer: The physical barrier between conditioned and unconditioned spaces
The building envelope includes walls, roofs, floors, windows, and doors that separate interior conditioned space from the exterior environment.
Question 2: Which insulation metric indicates resistance to heat flow per unit area?
- U-factor
- R-value (Correct answer)
- SHGC
- MERV rating
Correct answer: R-value
R-value measures thermal resistance; higher R-values indicate better insulating performance and reduced heat transfer.
Question 3: A blower door test is used primarily to measure:
- Duct leakage to the outside
- Overall building air infiltration rate (Correct answer)
- Attic ventilation adequacy
- Window U-factor performance
Correct answer: Overall building air infiltration rate
A blower door depressurizes the building and measures how much air leaks in, quantifying overall envelope airtightness.
Question 4: In climate zones with hot summers and mild winters, which strategy provides the greatest cooling energy savings?
- Adding basement insulation
- Installing high-SHGC west-facing windows
- Increasing roof reflectance with a cool roof (Correct answer)
- Switching to electric resistance heating
Correct answer: Increasing roof reflectance with a cool roof
Cool roofs with high solar reflectance reduce heat gain through the roof, directly lowering cooling loads in hot climates.
Question 5: The Energy Use Intensity (EUI) of a building is expressed as:
- kWh per installed watt
- BTU per square foot per year (Correct answer)
- Watts per occupant
- Therms per degree-day
Correct answer: BTU per square foot per year
EUI normalizes a building's total energy consumption by its floor area, typically expressed as kBtu per square foot per year.
Question 6: Which load type is reduced most directly by installing occupancy sensors in commercial spaces?
- Heating load
- Plug load
- Lighting load (Correct answer)
- Cooling load
Correct answer: Lighting load
Occupancy sensors automatically turn off lights when spaces are unoccupied, directly reducing the lighting electrical load.
Question 7: Thermal mass in a passive solar building functions by:
- Reflecting sunlight to reduce heat gain
- Absorbing and slowly releasing heat to moderate temperature swings (Correct answer)
- Conducting heat rapidly to outside air
- Increasing ventilation to cool the interior
Correct answer: Absorbing and slowly releasing heat to moderate temperature swings
High-density materials like concrete and masonry absorb solar heat during the day and release it slowly at night, stabilizing indoor temperatures.
NABCEP Energy Efficiency & Conservation Techniques 2
What does the term 'building envelope' refer to in energy efficiency?