Certified Energy Auditor Certification Certified Energy Auditor Building Envelope and Lighting 1 — Questions and Answers
Question 1: What does a lower U-factor value indicate about a window assembly's thermal performance?
- Greater solar heat gain through the glazing
- Higher resistance to non-solar heat flow (Correct answer)
- Increased visible light transmittance
- Reduced frame conductance only
Correct answer: Higher resistance to non-solar heat flow
U-factor measures the rate of non-solar heat transfer through a fenestration assembly; a lower U-factor means less heat flows through the assembly per unit area per degree of temperature difference, indicating better insulating performance.
Question 2: A building's south-facing windows have a Solar Heat Gain Coefficient (SHGC) of 0.25. What does this value indicate?
- 25% of incident solar radiation is transmitted into the building as heat (Correct answer)
- The windows block 25% of visible light
- The window U-factor is 0.25 BTU/hr·ft²·°F
- 25 watts per square foot of solar energy is absorbed by the frame
Correct answer: 25% of incident solar radiation is transmitted into the building as heat
SHGC represents the fraction of incident solar radiation — both directly transmitted and absorbed then re-radiated inward — that enters the building. An SHGC of 0.25 means 25% of solar energy striking the window becomes heat gain inside the building.
Question 3: Which lighting control strategy automatically dims or switches off electric lights in response to available natural light levels?
- Occupancy sensing
- Demand response load shedding
- Daylight harvesting with photosensors (Correct answer)
- Lumen depreciation compensation
Correct answer: Daylight harvesting with photosensors
Daylight harvesting uses photosensors to continuously measure ambient light levels and dim or turn off electric lighting when daylighting provides sufficient illuminance, reducing energy consumption while maintaining target light levels.
Question 4: An auditor recommends replacing cavity-only batt insulation with a wall assembly that adds a continuous layer of rigid foam insulation on the exterior. What is the primary thermal benefit of this change?
- It increases the wall's SHGC rating
- It eliminates thermal bridging through structural framing members (Correct answer)
- It improves the wall's air permeance class
- It raises interior surface temperatures above the dew point exclusively
Correct answer: It eliminates thermal bridging through structural framing members
Continuous exterior insulation wraps the entire wall surface — including studs — in an unbroken thermal layer, eliminating the conductive pathway that wood or metal framing creates through cavity insulation. This directly addresses thermal bridging, which can reduce effective wall R-value by 30–50% in stud-framed assemblies.
Question 5: A Color Rendering Index (CRI) of 90 for a lamp indicates that:
- The lamp produces 90 lumens per watt
- The lamp renders colors with 90% efficiency compared to incandescent sources
- The lamp accurately renders object colors relative to a reference illuminant at that value on a 100-point scale (Correct answer)
- The lamp operates at a correlated color temperature of 9000 K
Correct answer: The lamp accurately renders object colors relative to a reference illuminant at that value on a 100-point scale
CRI is a 100-point scale measuring how faithfully a light source renders colors compared to a reference illuminant of the same color temperature. A CRI of 90 is considered high-fidelity color rendering, making it suitable for retail, healthcare, and art spaces where accurate color perception matters.
Question 6: During a blower door test on a residential building, which building assembly location most commonly contributes the greatest share of measured air leakage?
- Below-grade foundation walls
- Exterior door weatherstripping
- Penetrations and bypasses at the ceiling plane and attic floor (Correct answer)
- Window glazing edge seals
Correct answer: Penetrations and bypasses at the ceiling plane and attic floor
Research consistently shows that the ceiling plane — including top-plate gaps, recessed lighting penetrations, plumbing and wiring chases, and attic bypasses — accounts for the largest single share of residential air leakage, often 30–40% of total infiltration. These pathways are driven by stack effect and are frequently overlooked during construction.
Certified Energy Auditor Certification Certified Energy Auditor Building Envelope and Lighting 1
What does a lower U-factor value indicate about a window assembly's thermal performance?