BPI Heating, Ventilation & Air Conditioning (HVAC) 4

Question 1

What is the primary risk of installing an oversized air conditioner in a humid climate?

Accepted Answer

Short cycling that prevents adequate dehumidification

Answer

An oversized AC cools the space quickly and shuts off before running long enough to remove sufficient moisture, leading to high indoor humidity despite comfortable temperatures.

Question 2

When assessing duct leakage with a duct blower, what does 'duct leakage to outside' (CFM25-out) measure?

Accepted Answer

Leakage from ducts located outside the conditioned space only

Answer

CFM25-out measures only the leakage from ducts located outside the conditioned building envelope (e.g., attic, crawlspace ducts), which directly affects energy loss.

Question 3

Which of the following best describes the role of the economizer in a commercial HVAC system?

Accepted Answer

Using outdoor air for free cooling when conditions are favorable

Answer

An economizer uses outdoor air for cooling when outdoor temperature and humidity are below set thresholds, reducing or eliminating mechanical cooling energy.

Question 4

What is the recommended method to verify adequate combustion air supply for a naturally drafted appliance?

Accepted Answer

Perform a draft test with a manometer before and after closing interior doors

Answer

Measuring draft pressure before and after closing interior doors reveals whether the appliance loses adequate combustion air supply under realistic building conditions.

Question 5

A homeowner's energy bills are high and the duct system is located in an unconditioned attic. What is the MOST impactful improvement?

Accepted Answer

Seal duct leaks and insulate ducts to at least R-8

Answer

Ducts in unconditioned attics lose substantial energy through both leakage and conduction; sealing leaks and adding R-8 insulation typically yields the greatest energy savings.

(BPI) Building Performance Institute Certified Practice Test

(BPI) Building Performance Institute Certified Practice Test

BPI Heating, Ventilation & Air Conditioning (HVAC) 4