HVAC NATE Heat Pump Questions And
Verified Answers Latest 2026 Update |
Graded A+ | 100% Success
Where should the sensing bulb on a TXV be located to obtain an accurate
refrigerant temperature on a horizontal suction line that is 1&1/8" or larger? -
Correct Answer -Should be located at 4 or 8 o'clock position on the line.
What factors affects a customer's level of comfort? - Correct Answer -Air
movement
Humidity
Temperature
What are the three processes that transfer heat energy? - Correct Answer -
Conduction
Convection
Radiation
Heat transfer that occurs when substances of different temperatures are in
contact with each other is called? - Correct Answer -Conduction
,What effect does raising the pressure in a sealed system have on refrigerant? -
Correct Answer -The refrigerants boiling point increases.
What is the primary danger to people near an accidental refrigerant release or
spill? - Correct Answer -Suffocation caused by the heavier refrigerant displacing
oxygen in the air.
The maximum temperature at which refrigerant may be stored is__________
when the container is no more than ________% full - Correct Answer -125F, 80%
Why is superheat necessary in a system that utilizes hermetic compression? -
Correct Answer -It ensures that dry vapor reaches the compressor so that
mechanical damage does not occur
When heat heat load on an evaporator increases, what is the effect on the
system? - Correct Answer -Suction pressure and discharge pressure both increase
,What type of energy is transferred when work is done in the condenser? - Correct
Answer -Both latent and sensible heat
Which component pumps refrigerant through the system and raises the
vapor temperature? - Correct Answer -Compressor
How are hermetic compressor motors cooled? - Correct Answer -With suction
vapor drawn from the evaporator
Heat pump compressors sometimes run hotter than compressors used in cooling-
only units because heat pump compressors _______. - Correct Answer -Exhibit
low refrigerant density at low suction
When is crankcase heat most needed? - Correct Answer -When the compressor is
off.
Work done on the refrigerant in the condenser is transferred as ________. -
Correct Answer -Both sensible and latent heat.
, Why are more circuits needed in the outdoor coils used in heat pumps than in the
condenser coils used in cooling - only units? - Correct Answer -To keep the
pressure drop across the outdoor coil low
What is the typical water flow rate per ton of cooling for water-source heat pumps
operating in closed - loop systems? - Correct Answer -3.0 gpm per ton
What tool should be used to shorten a capillary tube? - Correct Answer -A
triangular or knife-edge file
Which pressure in a TXV is the opening pressure? - Correct Answer -Bulb Pressure
What effect does a low refrigerant charge have on reversing valve operation? -
Correct Answer -It increases the chance that the reversing valve will not be able to
transfer properly
Which of the following should be used to leak-test refrigerant tubing? - Correct
Answer -Dry nitrogen
Verified Answers Latest 2026 Update |
Graded A+ | 100% Success
Where should the sensing bulb on a TXV be located to obtain an accurate
refrigerant temperature on a horizontal suction line that is 1&1/8" or larger? -
Correct Answer -Should be located at 4 or 8 o'clock position on the line.
What factors affects a customer's level of comfort? - Correct Answer -Air
movement
Humidity
Temperature
What are the three processes that transfer heat energy? - Correct Answer -
Conduction
Convection
Radiation
Heat transfer that occurs when substances of different temperatures are in
contact with each other is called? - Correct Answer -Conduction
,What effect does raising the pressure in a sealed system have on refrigerant? -
Correct Answer -The refrigerants boiling point increases.
What is the primary danger to people near an accidental refrigerant release or
spill? - Correct Answer -Suffocation caused by the heavier refrigerant displacing
oxygen in the air.
The maximum temperature at which refrigerant may be stored is__________
when the container is no more than ________% full - Correct Answer -125F, 80%
Why is superheat necessary in a system that utilizes hermetic compression? -
Correct Answer -It ensures that dry vapor reaches the compressor so that
mechanical damage does not occur
When heat heat load on an evaporator increases, what is the effect on the
system? - Correct Answer -Suction pressure and discharge pressure both increase
,What type of energy is transferred when work is done in the condenser? - Correct
Answer -Both latent and sensible heat
Which component pumps refrigerant through the system and raises the
vapor temperature? - Correct Answer -Compressor
How are hermetic compressor motors cooled? - Correct Answer -With suction
vapor drawn from the evaporator
Heat pump compressors sometimes run hotter than compressors used in cooling-
only units because heat pump compressors _______. - Correct Answer -Exhibit
low refrigerant density at low suction
When is crankcase heat most needed? - Correct Answer -When the compressor is
off.
Work done on the refrigerant in the condenser is transferred as ________. -
Correct Answer -Both sensible and latent heat.
, Why are more circuits needed in the outdoor coils used in heat pumps than in the
condenser coils used in cooling - only units? - Correct Answer -To keep the
pressure drop across the outdoor coil low
What is the typical water flow rate per ton of cooling for water-source heat pumps
operating in closed - loop systems? - Correct Answer -3.0 gpm per ton
What tool should be used to shorten a capillary tube? - Correct Answer -A
triangular or knife-edge file
Which pressure in a TXV is the opening pressure? - Correct Answer -Bulb Pressure
What effect does a low refrigerant charge have on reversing valve operation? -
Correct Answer -It increases the chance that the reversing valve will not be able to
transfer properly
Which of the following should be used to leak-test refrigerant tubing? - Correct
Answer -Dry nitrogen
