BPI Heating, Ventilation & Air Conditioning (HVAC) 2

Question 1

What is the primary purpose of a heat exchanger in a forced-air furnace?

Accepted Answer

To transfer heat from combustion gases to supply air without mixing them

Answer

The heat exchanger separates combustion gases from the air supply while transferring heat, preventing CO and other combustion byproducts from entering living spaces.

Question 2

A homeowner reports that their condensing furnace drains are backing up. What is the MOST likely cause?

Accepted Answer

Blocked or kinked condensate drain line

Answer

Condensing furnaces produce acidic condensate that must drain freely; a blocked or kinked drain line is the most common cause of backup.

Question 3

Which BPI diagnostic tool is used to measure airflow at supply and return registers?

Accepted Answer

Flow hood (capture hood)

Answer

A flow hood (capture hood) is placed over registers to measure the volume of air flowing through them in CFM.

Question 4

What does a high CO2 reading in flue gas analysis typically indicate?

Accepted Answer

Efficient combustion with proper air-fuel ratio

Answer

Higher CO2 in flue gases (up to the stoichiometric maximum) generally indicates more complete combustion and a better air-fuel mixture.

Question 5

What is the standard minimum ventilation rate prescribed by ASHRAE 62.2 for a 1,500 sq ft home with 3 occupants?

Accepted Answer

45 CFM

Answer

ASHRAE 62.2 calculates minimum ventilation as 0.03 CFM/sq ft × floor area + 7.5 CFM × (bedrooms + 1); for a 1,500 sq ft, 3-bedroom home this equals approximately 45 CFM.

(BPI) Building Performance Institute Certified Practice Test

(BPI) Building Performance Institute Certified Practice Test

BPI Heating, Ventilation & Air Conditioning (HVAC) 2