Diagnostic Testing & Performance Evaluation Flashcards
7 cards from real BPI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Diagnostic Testing & Performance Evaluation flashcards as text
What BPI standard governs the maximum acceptable undiluted CO level measured in the flue gases of a heating appliance?
Answer: 400 ppm
BPI standards set 400 ppm as the action threshold for undiluted flue gas CO; levels above this require the appliance to be shut down and serviced.
Which of the following best explains why blower door tests are conducted at 50 Pascals rather than natural pressure conditions?
Answer: Standardized pressure allows repeatable, comparable results across buildings and climates
Testing at 50 Pascals provides a standardized, repeatable pressure that amplifies leakage enough to measure accurately regardless of weather conditions or climate.
A technician measures a pressure difference of -5 Pascals between a mechanical room and the outdoors during worst-case testing. What action is required?
Answer: The combustion appliances must be immediately shut off and not restarted until the issue is resolved
BPI protocols require shutting off combustion appliances when the mechanical room is depressurized beyond -5 Pascals (worst-case), as backdrafting risk is unacceptable.
What does the term 'envelope leakage' refer to in BPI diagnostics?
Answer: Uncontrolled air movement through gaps in the building's thermal and pressure boundary
Envelope leakage refers to uncontrolled air infiltration and exfiltration through cracks, gaps, and penetrations in the building's outer shell.
During a comprehensive diagnostic assessment, what is the purpose of measuring 'room-to-room' pressures with the air handler running?
Answer: To identify pressure imbalances that indicate return air pathway problems
Room pressure measurements with the AHU running reveal return air pathway restrictions that cause pressure imbalances, which can worsen infiltration and backdrafting risks.
What is the primary limitation of visual inspection alone for identifying air leakage in a building?
Answer: Many significant leakage paths are hidden in wall cavities, attic bypasses, and other inaccessible areas
Air leakage often occurs in hidden locations such as top plates, wall-to-ceiling junctions, and attic bypasses that cannot be seen without diagnostic pressurization tools.
What condition during infrared thermography scanning indicates missing or displaced insulation in a wall cavity?
Answer: A warm spot on an exterior wall during winter heating conditions
A warm spot on an exterior wall during winter (when heat is escaping) indicates missing or displaced insulation allowing heat to conduct through the wall assembly.