HVAC Air Conditioning 4

Question 1

A technician finds that a TXV (thermostatic expansion valve) bulb has lost its charge. What symptom would this most likely cause?

Accepted Answer

Low suction pressure and starved evaporator

Answer

High suction pressure and flooding of compressor

Answer

High discharge pressure and high subcooling

Answer

Compressor short-cycling on high pressure

Question 2

What is the purpose of the reversing valve in a heat pump system?

Accepted Answer

Reverse the direction of refrigerant flow to switch between heating and cooling modes

Answer

Regulate refrigerant flow during defrost

Answer

Control compressor speed during mode changes

Answer

Bypass the metering device in heating mode

Question 3

Which term describes the process of refrigerant absorbing heat and changing from liquid to vapor in the evaporator?

Accepted Answer

Evaporation (vaporization)

Answer

Condensation

Answer

Sublimation

Answer

Compression

Question 4

What SEER rating is required for new central air conditioners sold in the southeastern United States as of 2023?

Accepted Answer

15 SEER (SEER2)

Answer

13 SEER

Answer

14 SEER

Answer

16 SEER

Question 5

A capacitor in an air conditioning system serves what primary purpose?

Accepted Answer

Provide starting torque and improve running efficiency of motors

Answer

Store energy for emergency compressor shutdown

Answer

Filter electrical noise from the control board

Answer

Step up voltage to the compressor motor

Question 6

What does 'latent heat' refer to in HVAC applications?

Accepted Answer

Heat absorbed or released during a phase change without a temperature change

Answer

Heat transferred by direct contact between surfaces

Answer

Heat that changes the temperature of a substance

Answer

Radiant heat from the sun entering through windows

Question 7

When recovering refrigerant from a system, the technician must use EPA-approved recovery equipment if the system contains more than how much refrigerant?

Accepted Answer

Any amount — recovery equipment is always required

Answer

5 pounds

Answer

50 pounds

Answer

More than 200 pounds