BPI Energy Auditing 5

Question 1

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

Accepted Answer

6.0 ACH50

Answer

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

Question 2

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

Accepted Answer

Infrared camera (thermographic imaging)

Answer

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

Question 3

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

Accepted Answer

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

Answer

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.

Question 4

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

Accepted Answer

Percent CO₂ or O₂ in flue gases

Answer

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.

Question 5

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

Accepted Answer

Heat that changes air temperature without a change in moisture content

Answer

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

(BPI) Building Performance Institute Certified Practice Test

(BPI) Building Performance Institute Certified Practice Test

BPI Energy Auditing 5