NATE AIR CONDITIONING SERVICE EXAM NEWEST
ACTUAL EXAM COMPLETE 100 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW VERSION!!
1. What is the primary function of the metering device in an AC system?
A. Raise refrigerant pressure
B. Lower refrigerant temperature ✔
C. Remove moisture
D. Increase refrigerant volume
The metering device lowers pressure, causing refrigerant to flash and cool.
2. Refrigerant leaves the evaporator as:
A. High-pressure liquid
B. Low-pressure vapor ✔
C. High-pressure vapor
D. Subcooled liquid
Evaporators boil refrigerant into low-pressure vapor.
3. Condensers reject heat to the:
A. Indoor air
B. Outdoor air ✔
C. Refrigerant vapor
D. Return duct
Condensers expel heat outdoors.
4. Superheat is measured at the:
A. Condenser outlet
B. Compressor inlet ✔
C. Metering device
, D. Return duct
Superheat ensures vapor only enters the compressor.
5. Subcooling is measured on the:
A. Suction line
B. Liquid line ✔
C. Discharge line
D. Evaporator outlet
Subcooling is a liquid-line measurement.
6. A restricted TXV will cause:
A. High suction pressure
B. Low suction pressure ✔
C. Flooding compressor
D. High evaporator load
A lack of refrigerant entering the evaporator lowers suction pressure.
7. Which component separates liquid from vapor?
A. Compressor
B. Receiver
C. Accumulator ✔
D. Condenser
Accumulators protect compressors from liquid slugging.
8. What happens when airflow across the evaporator is reduced?
A. Suction pressure rises
B. Suction pressure drops ✔
C. Head pressure rises
D. Superheat rises
Reduced airflow lowers heat load, lowering suction pressure.
9. High head pressure is typically caused by:
A. Low airflow
B. Dirty condenser coil ✔
C. Faulty thermostat
, D. Oversized TXV
Dirty condensers restrict heat rejection.
10.A starved evaporator results in:
A. High superheat ✔
B. Low superheat
C. High subcooling
D. Short cycling
Starving increases superheat because vapor is heated further.
11.Liquid slugging is most likely to occur at the:
A. TXV inlet
B. Compressor inlet ✔
C. Condenser outlet
D. Suction line filter
Slugging damages compressors and happens at suction inlet.
12.A system with high superheat and low subcooling is likely:
A. Overcharged
B. Undercharged ✔
C. TXV failed open
D. Condenser fan failure
Both readings indicate insufficient refrigerant.
13.A good evaporator superheat level is typically:
A. 0°F
B. 8–14°F ✔
C. 25–35°F
D. 40–50°F
Most systems target 8–14°F for stable operation.
14.The compressor’s job is to:
A. Absorb heat
B. Move refrigerant ✔
C. Raise cooling capacity
ACTUAL EXAM COMPLETE 100 QUESTIONS AND
CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW VERSION!!
1. What is the primary function of the metering device in an AC system?
A. Raise refrigerant pressure
B. Lower refrigerant temperature ✔
C. Remove moisture
D. Increase refrigerant volume
The metering device lowers pressure, causing refrigerant to flash and cool.
2. Refrigerant leaves the evaporator as:
A. High-pressure liquid
B. Low-pressure vapor ✔
C. High-pressure vapor
D. Subcooled liquid
Evaporators boil refrigerant into low-pressure vapor.
3. Condensers reject heat to the:
A. Indoor air
B. Outdoor air ✔
C. Refrigerant vapor
D. Return duct
Condensers expel heat outdoors.
4. Superheat is measured at the:
A. Condenser outlet
B. Compressor inlet ✔
C. Metering device
, D. Return duct
Superheat ensures vapor only enters the compressor.
5. Subcooling is measured on the:
A. Suction line
B. Liquid line ✔
C. Discharge line
D. Evaporator outlet
Subcooling is a liquid-line measurement.
6. A restricted TXV will cause:
A. High suction pressure
B. Low suction pressure ✔
C. Flooding compressor
D. High evaporator load
A lack of refrigerant entering the evaporator lowers suction pressure.
7. Which component separates liquid from vapor?
A. Compressor
B. Receiver
C. Accumulator ✔
D. Condenser
Accumulators protect compressors from liquid slugging.
8. What happens when airflow across the evaporator is reduced?
A. Suction pressure rises
B. Suction pressure drops ✔
C. Head pressure rises
D. Superheat rises
Reduced airflow lowers heat load, lowering suction pressure.
9. High head pressure is typically caused by:
A. Low airflow
B. Dirty condenser coil ✔
C. Faulty thermostat
, D. Oversized TXV
Dirty condensers restrict heat rejection.
10.A starved evaporator results in:
A. High superheat ✔
B. Low superheat
C. High subcooling
D. Short cycling
Starving increases superheat because vapor is heated further.
11.Liquid slugging is most likely to occur at the:
A. TXV inlet
B. Compressor inlet ✔
C. Condenser outlet
D. Suction line filter
Slugging damages compressors and happens at suction inlet.
12.A system with high superheat and low subcooling is likely:
A. Overcharged
B. Undercharged ✔
C. TXV failed open
D. Condenser fan failure
Both readings indicate insufficient refrigerant.
13.A good evaporator superheat level is typically:
A. 0°F
B. 8–14°F ✔
C. 25–35°F
D. 40–50°F
Most systems target 8–14°F for stable operation.
14.The compressor’s job is to:
A. Absorb heat
B. Move refrigerant ✔
C. Raise cooling capacity
