BPI Heating, Ventilation & Air Conditioning (HVAC) 3

Question 1

What is the purpose of measuring static pressure in an HVAC duct system?

Accepted Answer

To assess airflow resistance and identify restrictions that reduce system performance

Answer

Static pressure measurements reveal how much resistance exists in the duct system; high static pressure indicates restrictions that reduce airflow and system efficiency.

Question 2

Which refrigerant replaced R-22 as the standard for residential air conditioners due to lower ozone depletion potential?

Accepted Answer

R-410A

Answer

R-410A became the dominant replacement for R-22 in residential systems because it does not deplete the ozone layer, though it still has a high global warming potential.

Question 3

In a balanced ventilation system, what must be true about supply and exhaust airflows?

Accepted Answer

Supply and exhaust airflows are approximately equal

Answer

A balanced ventilation system maintains approximately equal supply and exhaust airflows to avoid pressurizing or depressurizing the building envelope.

Question 4

What is the function of an expansion valve (TXV) in a refrigeration cycle?

Accepted Answer

To meter refrigerant flow and reduce pressure before the evaporator

Answer

The thermostatic expansion valve (TXV) meters refrigerant flow into the evaporator and drops refrigerant pressure, enabling heat absorption at the evaporator coil.

Question 5

According to BPI standards, what CO level measured in ambient air during combustion appliance testing requires immediate action?

Accepted Answer

70 ppm

Answer

BPI protocols require immediate action (stopping work, evacuating, notifying the homeowner) when ambient CO reaches or exceeds 70 ppm during testing.

(BPI) Building Performance Institute Certified Practice Test

(BPI) Building Performance Institute Certified Practice Test

BPI Heating, Ventilation & Air Conditioning (HVAC) 3