NATE Air Conditioning and Heat Pump
2024/2025 Exam Questions and Answers
| Grade A+
Which of the following factors affects a customers level of comfort? - 🧠ANSWER
✔✔All of the above
A cooling load calculation estimates the sensible heat gain of the structure. The
cooling-only system should be within _____% of this calculated value. -
🧠ANSWER ✔✔+15%
The maximum sensible cooling capacity of a heat pump should be within
______% of the calculated sensible heat gain of a structure with a large heating
load. - 🧠ANSWER ✔✔+25%
The combined output of a heatpump and its auxiliary heat should not exceed
the calculated heat loss of a home by more than ____%. - 🧠ANSWER ✔✔15%
What amount of auxiliary electronic heat is needed when the output of a heat
pump on a design day equals 18,800 Btuh and the heat loss of a home is 29,700
Btuh? - 🧠ANSWER ✔✔3.2 kWh
The three processes that transfer heat energy are conduction, convection, and
_________. - 🧠ANSWER ✔✔Radiation
Page 1 of 30
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
,Heat transfer that occurs when substances of different temperatures are in
contact with each other is called _______. - 🧠ANSWER ✔✔conduction
What effect does raising the pressure in a sealed system have on refrigerant? -
🧠ANSWER ✔✔The boiling point increases
What is the primary danger to people near an accidental refrigerant release or
spill? - 🧠ANSWER ✔✔suffocation caused by the heavier refrigerant displacing
oxygen in the air
The maximum temperature at which refrigerant may be stored is ______ F
when the container is no more than ____% full of liquid by volume.; - 🧠ANSWER
✔✔125 F, 80%
Boiling of the refrigerant occurs in which system component? - 🧠ANSWER
✔✔Evaporator
Why is superheat necessary in a system that utilizes hermetic compressors -
🧠ANSWER ✔✔It ensures that dry vapor reaches the compressor so that
mechanical damage does not occur
When the heat load on an evaporator increases, what is the effect on the
system? - 🧠ANSWER ✔✔Suction pressure and discharge pressure both increase
Page 2 of 30
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
, What type of energy is transferred when work is done in the condenser? -
🧠ANSWER ✔✔Both latent and sensible heat energy
What is the primary function performed by a thermal expansion valve? -
🧠ANSWER ✔✔It maintains the correct superheat in the suction vapor leaving
the evaporator
Which component pumps refrigerant through the system and raises the vapor
temperature? - 🧠ANSWER ✔✔compressor
How are hermetic compressor motors cooled? - 🧠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 _____. - 🧠ANSWER
✔✔exhibit low refrigerant density at low suction pressures during the heating
cycle
When is crankcase heat most needed? - 🧠ANSWER ✔✔When the compressor is
off
Work done on the refrigerant in the condenser is transferred as ____. -
🧠ANSWER ✔✔Both sensible and latent heat
Page 3 of 30
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
2024/2025 Exam Questions and Answers
| Grade A+
Which of the following factors affects a customers level of comfort? - 🧠ANSWER
✔✔All of the above
A cooling load calculation estimates the sensible heat gain of the structure. The
cooling-only system should be within _____% of this calculated value. -
🧠ANSWER ✔✔+15%
The maximum sensible cooling capacity of a heat pump should be within
______% of the calculated sensible heat gain of a structure with a large heating
load. - 🧠ANSWER ✔✔+25%
The combined output of a heatpump and its auxiliary heat should not exceed
the calculated heat loss of a home by more than ____%. - 🧠ANSWER ✔✔15%
What amount of auxiliary electronic heat is needed when the output of a heat
pump on a design day equals 18,800 Btuh and the heat loss of a home is 29,700
Btuh? - 🧠ANSWER ✔✔3.2 kWh
The three processes that transfer heat energy are conduction, convection, and
_________. - 🧠ANSWER ✔✔Radiation
Page 1 of 30
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
,Heat transfer that occurs when substances of different temperatures are in
contact with each other is called _______. - 🧠ANSWER ✔✔conduction
What effect does raising the pressure in a sealed system have on refrigerant? -
🧠ANSWER ✔✔The boiling point increases
What is the primary danger to people near an accidental refrigerant release or
spill? - 🧠ANSWER ✔✔suffocation caused by the heavier refrigerant displacing
oxygen in the air
The maximum temperature at which refrigerant may be stored is ______ F
when the container is no more than ____% full of liquid by volume.; - 🧠ANSWER
✔✔125 F, 80%
Boiling of the refrigerant occurs in which system component? - 🧠ANSWER
✔✔Evaporator
Why is superheat necessary in a system that utilizes hermetic compressors -
🧠ANSWER ✔✔It ensures that dry vapor reaches the compressor so that
mechanical damage does not occur
When the heat load on an evaporator increases, what is the effect on the
system? - 🧠ANSWER ✔✔Suction pressure and discharge pressure both increase
Page 2 of 30
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
, What type of energy is transferred when work is done in the condenser? -
🧠ANSWER ✔✔Both latent and sensible heat energy
What is the primary function performed by a thermal expansion valve? -
🧠ANSWER ✔✔It maintains the correct superheat in the suction vapor leaving
the evaporator
Which component pumps refrigerant through the system and raises the vapor
temperature? - 🧠ANSWER ✔✔compressor
How are hermetic compressor motors cooled? - 🧠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 _____. - 🧠ANSWER
✔✔exhibit low refrigerant density at low suction pressures during the heating
cycle
When is crankcase heat most needed? - 🧠ANSWER ✔✔When the compressor is
off
Work done on the refrigerant in the condenser is transferred as ____. -
🧠ANSWER ✔✔Both sensible and latent heat
Page 3 of 30
COPYRIGHT©JOSHCLAY 2025/2026. YEAR PUBLISHED 2025. COMPANY REGISTRATION NUMBER:
619652435. TERMS OF USE. PRIVACY STATEMENT. ALL RIGHTS RESERVED
