Building Envelope & Energy Audit Flashcards
7 cards from real CCP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Building Envelope & Energy Audit flashcards as text
During a thermographic scan of a building envelope, which temperature differential between interior and exterior is generally considered the minimum for reliable results?
Answer: 10°F (5.6°C)
A minimum 10°F (5.6°C) temperature differential is generally required for infrared thermography to reliably detect thermal anomalies in building envelopes.
A blower door test on a commercial building reveals an air leakage rate of 0.40 CFM75/ft² of envelope area. How does this compare to ASHRAE 90.1 maximum allowances?
Answer: It exceeds ASHRAE 90.1 limits
ASHRAE 90.1 requires commercial envelope air leakage no greater than 0.40 CFM75/ft² for continuous air barriers, so this reading is at or near the limit depending on exact test conditions.
What is the primary purpose of a 'tracer gas' test in building envelope commissioning?
Answer: Quantifying infiltration rates and identifying leakage pathways
Tracer gas tests inject a non-toxic gas (such as SF6 or CO2) and measure its decay to quantify air infiltration rates and locate leakage pathways in the building envelope.
When conducting an energy audit for a facility with a large chiller plant, which metric is most useful for benchmarking chiller efficiency?
Answer: kW/ton
kW/ton is the standard metric for benchmarking chiller plant efficiency, representing electrical input per ton of cooling produced, with lower values indicating better performance.
In a Level II energy audit, a commissioning professional identifies that a roof assembly has a measured U-value of 0.065 Btu/h·ft²·°F. The design specified U-0.048. What is the most likely cause?
Answer: Thermal bridging through metal fasteners or framing
Thermal bridging through metal fasteners, clips, or structural framing significantly increases effective U-value beyond the nominal insulation value, commonly explaining discrepancies between design and measured performance.
Which ASTM standard governs the field measurement of air leakage through building envelopes using a calibrated fan pressurization method?
Answer: ASTM E779
ASTM E779 is the standard test method for determining air leakage rate by fan pressurization, widely used for commercial building envelope air tightness testing.
A commissioning professional reviewing window specifications notes a center-of-glass U-factor of 0.25 but an assembly U-factor of 0.35. What accounts for this difference?
Answer: Edge-of-glass and frame thermal bridging effects
Assembly U-factor includes edge-of-glass conduction and frame thermal bridging effects, which are always higher than the center-of-glass value representing only the glazing itself.