NATE Exam AC & HP questions with verified detailed ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
answers
Which of the following compressors are considered a dynamic compressor?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
a. Centrifugal
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b. Reciprocating
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d. Rotary
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c. Scroll - correct answer✔✔a (Centrifugal)
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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
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b. Superheated vapor / sub cooled liquid
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
c. Saturated vapor / saturated liquid
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
d. Hot gas / cool liquid - correct answer✔✔b (Superheated vapor / sub cooled liquid)
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Which one of the following are considered the best metering device of the industry?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
a. Capillary tube
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b. Thermal expansion valve
||\\//|| ||\\//|| ||\\//||
d. Constant pressure expansion valve
||\\//|| ||\\//|| ||\\//|| ||\\//||
c. Electronic expansion valve - correct 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 - correct 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 - correct 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 - correct 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 - correct 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 - correct 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 - correct answer✔✔b (overcharge system)
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
answers
Which of the following compressors are considered a dynamic compressor?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
a. Centrifugal
||\\//||
b. Reciprocating
||\\//||
d. Rotary
||\\//||
c. Scroll - correct 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 - correct 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 - correct 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 - correct 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 - correct 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 - correct 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 - correct 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 - correct 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 - correct answer✔✔b (overcharge system)
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
