Energy Auditing Flashcards

A BPI auditor measures 1,200 CFM50 in a 1,500 sq ft single-story home with 8-ft ceilings. What is the ACH50?

Answer: 6.0 ACH50

ACH50 = (CFM50 × 60) / conditioned volume; volume = 1,500 ft² × 8 ft = 12,000 ft³; ACH50 = (1,200 × 60) / 12,000 = 6.0 ACH50.

Which diagnostic tool uses infrared radiation to visualize temperature differences across building surfaces during an energy audit?

Answer: Infrared camera (thermographic imaging)

An infrared camera detects surface temperature variations that can reveal missing insulation, air leaks, moisture intrusion, and thermal bridges.

What is the function of a 'sacrificial anode rod' in a water heater, and why is it relevant to energy auditing?

Answer: It prevents tank corrosion; relevant because a failed anode shortens water heater life and increases replacement costs

A sacrificial anode rod corrodes preferentially to protect the tank; an auditor notes its condition because premature tank failure increases lifecycle energy and replacement costs.

When performing a combustion efficiency test on a gas furnace, which measurement is used along with flue gas temperature to calculate steady-state efficiency?

Answer: Percent CO₂ or O₂ in flue gases

Combustion efficiency is calculated from flue gas temperature and CO₂ (or O₂) percentage using the Orsat or equivalent method to determine excess air and heat loss up the flue.

Which of the following best describes 'sensible heat' as distinct from 'latent heat' in HVAC and energy auditing?

Answer: Heat that changes air temperature without a change in moisture content

Sensible heat changes the temperature of air or a material, while latent heat changes moisture phase (e.g., evaporation/condensation) without changing temperature.

An energy auditor finds elevated CO readings in a home with a sealed combustion boiler. What is the most likely explanation?

Answer: CO is entering from an attached garage or other source unrelated to the boiler

Sealed combustion appliances draw combustion air from outside and are unlikely to spill CO indoors; elevated ambient CO most likely originates from another source such as an attached garage or vehicle.

What is the primary reason BPI protocols require energy auditors to check for asbestos-containing materials before recommending insulation work in older homes?

Answer: Disturbing asbestos-containing materials can release fibers that cause serious lung disease

Asbestos fibers released during disturbance of ACMs can cause mesothelioma, asbestosis, and lung cancer; auditors must identify risk before any retrofit work proceeds.