NATE Exam: Air Conditioning And Heat Pump (AC
& HP) – Questions/Answers
a (Centrifugal) ✔️Ans - Which of the following compressors are
considered a dynamic compressor?
a. Centrifugal
b. Reciprocating
d. Rotary
c. Scroll
b (Superheated vapor / sub cooled liquid) ✔️Ans - 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
b (Thermal expansion valve) ✔️Ans - 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
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.) ✔️Ans - 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
, b (Compressor discharge / compressor suction) ✔️Ans - 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
d (restricted liquid line filter/drier) ✔️Ans - 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
c (overfeeding metering device) ✔️Ans - 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
a (weak compressor valves) ✔️Ans - 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
& HP) – Questions/Answers
a (Centrifugal) ✔️Ans - Which of the following compressors are
considered a dynamic compressor?
a. Centrifugal
b. Reciprocating
d. Rotary
c. Scroll
b (Superheated vapor / sub cooled liquid) ✔️Ans - 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
b (Thermal expansion valve) ✔️Ans - 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
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.) ✔️Ans - 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
, b (Compressor discharge / compressor suction) ✔️Ans - 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
d (restricted liquid line filter/drier) ✔️Ans - 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
c (overfeeding metering device) ✔️Ans - 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
a (weak compressor valves) ✔️Ans - 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
