NATE EXAM |VERIFIED QUESTIONS AND CORRECT DETAILED
ANSWERS|RATED AND GRADED A+ NEW UPDATE| 2026/2027
Which of the following compressors are considered a dynamic compressor?
a. Centrifugal
b. Reciprocating
d. Rotary
c. Scroll - ANSWER✔ a (Centrifugal)
What is the condition of the refrigerant as it enters and leaves the condensing coil of a typical light
commercial HVAC system?
a. Vapor / liquid
b. Superheated vapor / sub cooled liquid
c. Saturated vapor / saturated liquid
d. Hot gas / cool liquid - ANSWER✔ b (Superheated vapor / sub cooled liquid)
Which one of the following are considered the best metering device of the industry?
a. Capillary tube
b. Thermal expansion valve
d. Constant pressure expansion valve
c. Electronic expansion valve - ANSWER✔ b (Thermal expansion valve)
Which of the following types of refrigeration oil would you expect to find in a typical commercial R-134a
freezer?
,a. Mineral 150
b. POE
c. AB
d. Mineral 300 - ANSWER✔ b (POE. Newer refrigerant systems today using R-134a and R-410a use a
synthetic Polyester POE oil. Older refrigeration systems using R-12, R-502, and R-22 use a mineral based
oil.)
Where does the small single port tube and the larger middle port tube go on a typical residential or light
commercial reversing valve?
a. Inlet outdoor coil / inlet indoor coil
b. Compressor discharge / compressor suction
c. Compressor suction / compressor discharge
c. Outlet indoor coil / outlet outdoor coil - ANSWER✔ b (Compressor discharge / compressor suction)
If you were working on a 3.5 ton split system, with a 125,000 BTH/H horizontal furnace, and you had a
low suction pressure, low discharge pressure, high superheat, and high subcooling, what is wrong with
the system?
a. low refrigerant charge
b. overcharged system
c. overfeeding metering device
d. restricted liquid line filter/drier - ANSWER✔ d (restricted liquid line filter/drier)
If you were working on a 3.5 ton split system, with a 125,000 BTU/H horizontal furnace, and you had
high suction pressure, low discharge pressure, low superheat, and low subcooling, what is wrong with
the system?
a. low refrigerant charge
b. overcharged system
c. overfeeding metering device
, d. restricted liquid line filter/drier - ANSWER✔ c (overfeeding metering device)
If you were working on a 3.5 ton split system, with a 125,000 BTU/H horizontal furnace, and you had
high suction pressure, low discharge pressure, high superheat, and low subcooling, what is wrong with
the system?
a. weak compressor valves
b. stuck reversing valve
c. bad indoor check valve
d. bad outdoor check valve - ANSWER✔ a (weak compressor valves)
If you were working on a 3.5 ton split system, with a 125,000 BTU/H horizontal furnace, and you had
high suction pressure, high discharge pressure, low superheat, and high subcooling, what is wrong with
the system?
a. low refrigerant charge
b. overcharged system
c. overfeeding metering device
d. restricted liquid line filter/drier - ANSWER✔ b (overcharge system)
You are working on a heat pump package unit and come across a charge compensator, what is it used
for?
a. to compensate for a low refrigerant charge
b. to compensate for an overcharged system
c. to compensate charge in the heating cycle
d. to compensate charge in the cooling cycle - ANSWER✔ d (to compensate charge in the cooling
cycle)
You are working on a heat pump package unit with a charge compensator, how is the charge
compensator connected to the refrigeration system?
ANSWERS|RATED AND GRADED A+ NEW UPDATE| 2026/2027
Which of the following compressors are considered a dynamic compressor?
a. Centrifugal
b. Reciprocating
d. Rotary
c. Scroll - ANSWER✔ a (Centrifugal)
What is the condition of the refrigerant as it enters and leaves the condensing coil of a typical light
commercial HVAC system?
a. Vapor / liquid
b. Superheated vapor / sub cooled liquid
c. Saturated vapor / saturated liquid
d. Hot gas / cool liquid - ANSWER✔ b (Superheated vapor / sub cooled liquid)
Which one of the following are considered the best metering device of the industry?
a. Capillary tube
b. Thermal expansion valve
d. Constant pressure expansion valve
c. Electronic expansion valve - ANSWER✔ b (Thermal expansion valve)
Which of the following types of refrigeration oil would you expect to find in a typical commercial R-134a
freezer?
,a. Mineral 150
b. POE
c. AB
d. Mineral 300 - ANSWER✔ b (POE. Newer refrigerant systems today using R-134a and R-410a use a
synthetic Polyester POE oil. Older refrigeration systems using R-12, R-502, and R-22 use a mineral based
oil.)
Where does the small single port tube and the larger middle port tube go on a typical residential or light
commercial reversing valve?
a. Inlet outdoor coil / inlet indoor coil
b. Compressor discharge / compressor suction
c. Compressor suction / compressor discharge
c. Outlet indoor coil / outlet outdoor coil - ANSWER✔ b (Compressor discharge / compressor suction)
If you were working on a 3.5 ton split system, with a 125,000 BTH/H horizontal furnace, and you had a
low suction pressure, low discharge pressure, high superheat, and high subcooling, what is wrong with
the system?
a. low refrigerant charge
b. overcharged system
c. overfeeding metering device
d. restricted liquid line filter/drier - ANSWER✔ d (restricted liquid line filter/drier)
If you were working on a 3.5 ton split system, with a 125,000 BTU/H horizontal furnace, and you had
high suction pressure, low discharge pressure, low superheat, and low subcooling, what is wrong with
the system?
a. low refrigerant charge
b. overcharged system
c. overfeeding metering device
, d. restricted liquid line filter/drier - ANSWER✔ c (overfeeding metering device)
If you were working on a 3.5 ton split system, with a 125,000 BTU/H horizontal furnace, and you had
high suction pressure, low discharge pressure, high superheat, and low subcooling, what is wrong with
the system?
a. weak compressor valves
b. stuck reversing valve
c. bad indoor check valve
d. bad outdoor check valve - ANSWER✔ a (weak compressor valves)
If you were working on a 3.5 ton split system, with a 125,000 BTU/H horizontal furnace, and you had
high suction pressure, high discharge pressure, low superheat, and high subcooling, what is wrong with
the system?
a. low refrigerant charge
b. overcharged system
c. overfeeding metering device
d. restricted liquid line filter/drier - ANSWER✔ b (overcharge system)
You are working on a heat pump package unit and come across a charge compensator, what is it used
for?
a. to compensate for a low refrigerant charge
b. to compensate for an overcharged system
c. to compensate charge in the heating cycle
d. to compensate charge in the cooling cycle - ANSWER✔ d (to compensate charge in the cooling
cycle)
You are working on a heat pump package unit with a charge compensator, how is the charge
compensator connected to the refrigeration system?
