NATE CORE EXAM QUESTIONS AND
ANSWERS 100% PASS 2026 UPDATE.
What makes a contract legal? - ANS Any verbal or written agreement.
Why should hacksaws and power saws not be used when cutting tubing or refrigerant lines? -
ANS The small shavings created by the teeth of the saw can enter the tubing and do damage
to the components of the system.
Why should tube cutters be used? - ANS They produce a square, clean cut and leave no
shavings to contaminate the system.
What can be used to cut capillary tubing? - ANS A triangular file or a knife edge file.
How should tubing be cut? - ANS It should be scored all the way around the outside and then
snapped to prevent closing of the inside diameter.
What can be used to remove a burr on the inside of tubing? - ANS Reamers and deburrers.
What does burring cause on the inside of tubing? - ANS It can create turbulence and pressure
drop inside the piping.
What can be used on soft drawn copper to provide a bend without kinking or damaging the
tubing? - ANS Tube benders.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Spring-Type benders can only be used on what type of tubbing? - ANS Soft drawn copper
What is the purpose of a flaring tool? - ANS It allows you to join soft drawn copper tubing
without the use of a coupling.
What is the purpose of a swaging tool? - ANS A method of joining tubing without a fitting.
After flaring, swaging, and connecting the tubing, what do you do next? - ANS You either
solder or braze the connection.
Describe the glass stem thermometer. - ANS It has a liquid filled tube marked off with a
graduated temperature scale.
What are some characteristics of a dial stem thermometer? - ANS Not quite as accurate as
the glass stem thermometer, but it is low cost and durable.
What do the glass stem thermometer and the dial stem thermometer measure? - ANS Dry-
bulb temperature.
What temperature is in relation to human comfort? - ANS Dry-bulb temperature.
What is a sling psychometer? - ANS It combines glass stem thermometers to measure both
dry-bulb and wet-bulb temperatures.
What is needed with the sling psychometer to measure temperatures? - ANS A psychometric
chart or slide rule.
What can the dry-bulb and wet-bulb temperatures be used to determine? - ANS Relative
humidity (%RH) The dew points. Other properties of the air.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, What can be used to calculate the relative humidity, dew point, and other properties of the air?
- ANS The difference between the wet-bulb and the dry-bulb temperature.
Explain the effects of relative humidity. - ANS By increasing the humidity during the heating
season, the evaporation of moisture is slowed, therefore you feel warmer and vice versa.
What is the digital psychrometer able to do? - ANS It is capable of reading dry-bulb and wet-
bulb temperature and %RH.
How do you find absolute pressure? - ANS Gauge pressure + 14.7PSI
What does a pressure gauge use as the operating element? - ANS A bourdon tube.
Describe the manifold gauge set. - ANS On the right = High pressure (Liquid) (discharge
gauge) (Red) On the left = Compound or suction gauge (Blue) (Vapor)
What is often used to measure pressure drop? (The difference in pressure between two points.)
- ANS Differential pressure gauges.
What can differential pressure gauges do? - ANS They can calculate air flow. They can help
you determine how clean or dirty a coil or filter is. Provides simultaneous pressure and flow
measurements
Before you charge a system with refrigerant or after you have replaced a component or repaired
a leak, you should? - ANS Remove all air and moisture from the system.
How do you remove noncondensables, air, and moisture from a system? - ANS Drawing a
deep vacuum with a vacuum pump.
What measurement is used to measure a vacuum? - ANS Microns.
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
ANSWERS 100% PASS 2026 UPDATE.
What makes a contract legal? - ANS Any verbal or written agreement.
Why should hacksaws and power saws not be used when cutting tubing or refrigerant lines? -
ANS The small shavings created by the teeth of the saw can enter the tubing and do damage
to the components of the system.
Why should tube cutters be used? - ANS They produce a square, clean cut and leave no
shavings to contaminate the system.
What can be used to cut capillary tubing? - ANS A triangular file or a knife edge file.
How should tubing be cut? - ANS It should be scored all the way around the outside and then
snapped to prevent closing of the inside diameter.
What can be used to remove a burr on the inside of tubing? - ANS Reamers and deburrers.
What does burring cause on the inside of tubing? - ANS It can create turbulence and pressure
drop inside the piping.
What can be used on soft drawn copper to provide a bend without kinking or damaging the
tubing? - ANS Tube benders.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Spring-Type benders can only be used on what type of tubbing? - ANS Soft drawn copper
What is the purpose of a flaring tool? - ANS It allows you to join soft drawn copper tubing
without the use of a coupling.
What is the purpose of a swaging tool? - ANS A method of joining tubing without a fitting.
After flaring, swaging, and connecting the tubing, what do you do next? - ANS You either
solder or braze the connection.
Describe the glass stem thermometer. - ANS It has a liquid filled tube marked off with a
graduated temperature scale.
What are some characteristics of a dial stem thermometer? - ANS Not quite as accurate as
the glass stem thermometer, but it is low cost and durable.
What do the glass stem thermometer and the dial stem thermometer measure? - ANS Dry-
bulb temperature.
What temperature is in relation to human comfort? - ANS Dry-bulb temperature.
What is a sling psychometer? - ANS It combines glass stem thermometers to measure both
dry-bulb and wet-bulb temperatures.
What is needed with the sling psychometer to measure temperatures? - ANS A psychometric
chart or slide rule.
What can the dry-bulb and wet-bulb temperatures be used to determine? - ANS Relative
humidity (%RH) The dew points. Other properties of the air.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, What can be used to calculate the relative humidity, dew point, and other properties of the air?
- ANS The difference between the wet-bulb and the dry-bulb temperature.
Explain the effects of relative humidity. - ANS By increasing the humidity during the heating
season, the evaporation of moisture is slowed, therefore you feel warmer and vice versa.
What is the digital psychrometer able to do? - ANS It is capable of reading dry-bulb and wet-
bulb temperature and %RH.
How do you find absolute pressure? - ANS Gauge pressure + 14.7PSI
What does a pressure gauge use as the operating element? - ANS A bourdon tube.
Describe the manifold gauge set. - ANS On the right = High pressure (Liquid) (discharge
gauge) (Red) On the left = Compound or suction gauge (Blue) (Vapor)
What is often used to measure pressure drop? (The difference in pressure between two points.)
- ANS Differential pressure gauges.
What can differential pressure gauges do? - ANS They can calculate air flow. They can help
you determine how clean or dirty a coil or filter is. Provides simultaneous pressure and flow
measurements
Before you charge a system with refrigerant or after you have replaced a component or repaired
a leak, you should? - ANS Remove all air and moisture from the system.
How do you remove noncondensables, air, and moisture from a system? - ANS Drawing a
deep vacuum with a vacuum pump.
What measurement is used to measure a vacuum? - ANS Microns.
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
