NATE HVAC TECHNICIAN CERTIFICATION PRACTICE STUDY GUIDE - ORIGINAL QUESTIONS
PRACTICE Q&A | STUDY GUIDE | NATE HVAC CORE + SPECIALTY
NATE HVAC
TECHNICIAN
2026/2027
NATE HVAC TECHNICIAN CERTIFICATION EXAMINATION
PRACTICE STUDY GUIDE - 150 ORIGINAL QUESTIONS + DETAILED SOLUTIONS
BASED ON NATE KATEs | NOT ACTUAL EXAM | STUDY PURPOSE ONLY
150Q PRACTICE STUDY GUIDE DETAILED
ORIGINAL 2026-27 SOLUTIONS
INCLUDES:
• HVAC Fundamentals, Electrical, Refrigeration, Airflow, Safety, Tools
• Heat Pumps, Gas Heat, AC Service + Installation, NATE KATEs
• 150 Original Practice Questions + Answers + Detailed Explanations
• Professional Study Guide | Borders + Page Numbers | 2026/2027 Edition
NATE HVAC Technician Practice Guide | Not affiliated with NATE | Educational Only
Original Practice Questions - Not Actual Exam Content
,HVAC Fundamentals Electrical Refrigeration Airflow Safety NATE KATEs
Description: NATE HVAC Technician Certification Practice Study Guide core HVAC fundamentals based on NATE Knowledge Areas of Technician Expertise KATEs,
HVAC fundamentals heat transfer conduction convection radiation, thermodynamics laws, pressure temperature relationship, gas laws, electrical fundamentals Ohms Law
V equals I times R, series parallel circuits, transformers, contactors relays, safety fundamentals OSHA, tool safety, electrical safety LOTO Lockout Tagout procedures
disconnect verification, refrigeration cycle fundamentals compression cycle four components compressor condenser metering device evaporator, states of refrigerant
subcooled liquid saturated mixture superheated vapor, superheat calculation suction line temp minus saturation temp at suction pressure, subcooling saturation temp at
liquid pressure minus liquid line temp, airflow fundamentals CFM cubic feet per minute, static pressure TESP total external static pressure supply plus return,
psychrometrics dry bulb wet bulb relative humidity dew point, refrigeration and refrigerants refrigerant types CFC HCFC HFC HFO A1 A2L safety, recovery evacuation
reclamation EPA Section 608, electrical and controls electrical components capacitors start run testing MFD rating, motors PSC ECM, troubleshooting motors, safety and
tools hand tools manifold gauges digital, vacuum pump micron gauge, leak detection, NATE Core exam covers fundamentals.
Heat Pumps Gas Heat AC Service Installation Troubleshooting NATE
Description: Heat pumps operation heat pump refrigeration cycle reversing valve, heating mode absorbs heat outdoor coil, cooling mode reverses, defrost cycle
time-temperature demand defrost sensor, auxiliary emergency heat electric strip, balance point, troubleshooting low charge reversing valve failure, gas heat fundamentals
gas heating sequence operation thermostat call R-W inducer motor pressure switch proves draft ignitor HSI or spark gas valve opens flame sensor proves rectification
blower on, safety devices high limit rollout switch, combustion analysis O2 CO draft, troubleshooting no heat causes, air conditioning service and installation AC installation
practices line set brazing nitrogen purge, evacuation deep vacuum 500 microns decay test, charging methods weigh-in superheat subcooling, airflow setting blower speed
CFM per ton 350-450, service troubleshooting low charge high superheat low subcooling, overcharge high subcooling, restriction, non-condensables, compressor
diagnostics, NATE Specialty exams include Air Conditioning AC Service 100 questions, AC Installation, Air Distribution, Heat Pump Service Installation, Gas Heating
Service Installation, Oil Heating, Commercial Refrigeration, Light Commercial, Efficiency Analyst, NATE certification process experience 2 years recommended, Core exam
plus Specialty, Ready to Work entry level, HVAC Support Technician, recertification 16 hours CE every 2 years, KATEs domains Safety 9 percent Tools 11 percent Basic
Construction 7 percent Basic Science 13 percent Achieving Desired Conditions 16 percent Taking Temperature Pressure 15 percent Basic Electrical 17 percent Piping
Service Installation 12 percent.
NATE HVAC Exam Domains KATEs Certification Study Guide 2026
Description: NATE HVAC Technician Certification Practice Study Guide domains based on NATE KATEs Knowledge Areas of Technician Expertise, credential NATE
Certified Technician Core plus Specialty certification recognized industry standard HVAC excellence, eligibility recommended 1-2 years field experience, Ready to Work no
experience, Core exam 100 questions, Specialty exams 100 questions 70 percent passing, exam blueprint Core: Safety 9 percent LOTO PPE, Tools 11 percent manifold
gauges vacuum pump, Basic Construction 7 percent job site, Basic Science 13 percent heat transfer gas laws, Achieving Desired Conditions 16 percent comfort
psychrometrics, Taking Temp Pressure Measurements 15 percent superheat subcooling TESP, Basic Electrical 17 percent Ohms Law capacitors motors, Piping Service
Installation 12 percent brazing evacuation, Specialty AC Service: Installation 13 percent evacuation charging, Service 46 percent diagnostics superheat subcooling
electrical, System Components 25 percent compressor TXV, Air Distribution 16 percent airflow duct, Gas Heat Service: Installation 19 percent venting gas piping, Service
48 percent sequence operation troubleshooting flame sensor ignitor, System Components 20 percent gas valve inducer, Air Distribution 13 percent temperature rise, Heat
Pump Service: Installation 16 percent reversing valve defrost, Service 43 percent defrost charge, System Components 25 percent TXV compressor, Air Distribution 16
percent balance point, study materials NATE KATEs, EPA 608, Modern Refrigeration and Air Conditioning, latest 2026/2027 based on NATE KATEs, 150 original practice
questions answers detailed solutions for NATE HVAC candidates, HVAC core electrical refrigeration airflow safety tools superheat subcooling TESP TXV capacitors defrost
gas sequence LOTO, NATE HVAC candidates exam preparation, NATE HVAC Technician Certification Examination Practice Guide, study guide borders page numbers
improved cover page educational purposes.
Page 2 - NATE HVAC Practice 150Q 2026/2027
,Question 1: Q1: What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction
pressure indicates evaporator charge prevents floodback
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction pressure indicates evaporator
charge prevents floodback - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
C. Incorrect: Confuses is with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: B. What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction
pressure indicates evaporator charge prevents floodback - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction pressure indicates evaporator charge
prevents floodback - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC
technician certification original practice.
Question 2: Q2: What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured
saturation liquid minus liquid line
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses does with unrelated system component and wrong measurement method
C. What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured saturation liquid minus liquid line -
detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: C. What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured
saturation liquid minus liquid line - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured saturation liquid minus liquid line - detailed
explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification original
practice.
Question 3: Q3: What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant
superheat sensing bulb
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses is with unrelated system component and wrong measurement method
C. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
D. What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant superheat sensing bulb - detailed
explanation per NATE KATEs Knowledge Areas of Technician Expertise
CORRECT ANSWER: D. What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant
superheat sensing bulb - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant superheat sensing bulb - detailed
explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification original
practice.
Question 4: Q4: How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer
compare rating 0.5 inch WC indicates restrictive duct dirty filter
A. How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer compare rating 0.5 inch WC indicates
restrictive duct dirty filter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
B. Incorrect: Misinterpretation of How leading to wrong diagnostic and unsafe practice per NATE
C. Incorrect: Confuses do with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for How
CORRECT ANSWER: A. How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer
compare rating 0.5 inch WC indicates restrictive duct dirty filter - detailed explanation per NATE KATEs Knowledge Areas of Technician
Expertise
RATIONALE:
Rationale: How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer compare rating 0.5 inch WC indicates restrictive
duct dirty filter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician
certification original practice.
Question 5: Q5: What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor
glows gas valve opens flame sensor proves blower on safeties
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor glows gas valve opens flame
sensor proves blower on safeties - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
C. Incorrect: Confuses is with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: B. What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor
glows gas valve opens flame sensor proves blower on safeties - detailed explanation per NATE KATEs Knowledge Areas of Technician
Expertise
RATIONALE:
Rationale: What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor glows gas valve opens flame sensor
proves blower on safeties - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC
technician certification original practice.
Page 3 - NATE HVAC Practice 150Q 2026/2027
, Question 6: Q6: What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand
reverses refrigerant heats outdoor coil auxiliary heat
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses causes with unrelated system component and wrong measurement method
C. What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand reverses refrigerant heats outdoor
coil auxiliary heat - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: C. What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand
reverses refrigerant heats outdoor coil auxiliary heat - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand reverses refrigerant heats outdoor coil
auxiliary heat - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician
certification original practice.
Question 7: Q7: What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run
lower failure hum no start test meter
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses is with unrelated system component and wrong measurement method
C. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
D. What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run lower failure hum no start test
meter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
CORRECT ANSWER: D. What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run
lower failure hum no start test meter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run lower failure hum no start test meter -
detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification
original practice.
Question 8: Q8: How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed
evaporator iced blower speed static pressure high
A. How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed evaporator iced blower speed static
pressure high - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
B. Incorrect: Misinterpretation of How leading to wrong diagnostic and unsafe practice per NATE
C. Incorrect: Confuses do with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for How
CORRECT ANSWER: A. How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed
evaporator iced blower speed static pressure high - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed evaporator iced blower speed static pressure high
- detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification
original practice.
Question 9: Q9: What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to
Work HVAC Support Gas Heat Heat Pump AC Service KATEs 2 years recert 2 years
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to Work HVAC Support Gas Heat
Heat Pump AC Service KATEs 2 years recert 2 years - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
C. Incorrect: Confuses is with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: B. What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to
Work HVAC Support Gas Heat Heat Pump AC Service KATEs 2 years recert 2 years - detailed explanation per NATE KATEs Knowledge Areas
of Technician Expertise
RATIONALE:
Rationale: What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to Work HVAC Support Gas Heat Heat
Pump AC Service KATEs 2 years recert 2 years - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct
troubleshooting for HVAC technician certification original practice.
Question 10: Q10: Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter
discharge capacitors PPE 24V high voltage 120/240/480 OSHA
A. Incorrect: Misinterpretation of Electrical leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses safety with unrelated system component and wrong measurement method
C. Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter discharge capacitors PPE 24V high
voltage 120/240/480 OSHA - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for Electrical
CORRECT ANSWER: C. Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter
discharge capacitors PPE 24V high voltage 120/240/480 OSHA - detailed explanation per NATE KATEs Knowledge Areas of Technician
Expertise
RATIONALE:
Rationale: Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter discharge capacitors PPE 24V high voltage
120/240/480 OSHA - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC
technician certification original practice.
Page 4 - NATE HVAC Practice 150Q 2026/2027
PRACTICE Q&A | STUDY GUIDE | NATE HVAC CORE + SPECIALTY
NATE HVAC
TECHNICIAN
2026/2027
NATE HVAC TECHNICIAN CERTIFICATION EXAMINATION
PRACTICE STUDY GUIDE - 150 ORIGINAL QUESTIONS + DETAILED SOLUTIONS
BASED ON NATE KATEs | NOT ACTUAL EXAM | STUDY PURPOSE ONLY
150Q PRACTICE STUDY GUIDE DETAILED
ORIGINAL 2026-27 SOLUTIONS
INCLUDES:
• HVAC Fundamentals, Electrical, Refrigeration, Airflow, Safety, Tools
• Heat Pumps, Gas Heat, AC Service + Installation, NATE KATEs
• 150 Original Practice Questions + Answers + Detailed Explanations
• Professional Study Guide | Borders + Page Numbers | 2026/2027 Edition
NATE HVAC Technician Practice Guide | Not affiliated with NATE | Educational Only
Original Practice Questions - Not Actual Exam Content
,HVAC Fundamentals Electrical Refrigeration Airflow Safety NATE KATEs
Description: NATE HVAC Technician Certification Practice Study Guide core HVAC fundamentals based on NATE Knowledge Areas of Technician Expertise KATEs,
HVAC fundamentals heat transfer conduction convection radiation, thermodynamics laws, pressure temperature relationship, gas laws, electrical fundamentals Ohms Law
V equals I times R, series parallel circuits, transformers, contactors relays, safety fundamentals OSHA, tool safety, electrical safety LOTO Lockout Tagout procedures
disconnect verification, refrigeration cycle fundamentals compression cycle four components compressor condenser metering device evaporator, states of refrigerant
subcooled liquid saturated mixture superheated vapor, superheat calculation suction line temp minus saturation temp at suction pressure, subcooling saturation temp at
liquid pressure minus liquid line temp, airflow fundamentals CFM cubic feet per minute, static pressure TESP total external static pressure supply plus return,
psychrometrics dry bulb wet bulb relative humidity dew point, refrigeration and refrigerants refrigerant types CFC HCFC HFC HFO A1 A2L safety, recovery evacuation
reclamation EPA Section 608, electrical and controls electrical components capacitors start run testing MFD rating, motors PSC ECM, troubleshooting motors, safety and
tools hand tools manifold gauges digital, vacuum pump micron gauge, leak detection, NATE Core exam covers fundamentals.
Heat Pumps Gas Heat AC Service Installation Troubleshooting NATE
Description: Heat pumps operation heat pump refrigeration cycle reversing valve, heating mode absorbs heat outdoor coil, cooling mode reverses, defrost cycle
time-temperature demand defrost sensor, auxiliary emergency heat electric strip, balance point, troubleshooting low charge reversing valve failure, gas heat fundamentals
gas heating sequence operation thermostat call R-W inducer motor pressure switch proves draft ignitor HSI or spark gas valve opens flame sensor proves rectification
blower on, safety devices high limit rollout switch, combustion analysis O2 CO draft, troubleshooting no heat causes, air conditioning service and installation AC installation
practices line set brazing nitrogen purge, evacuation deep vacuum 500 microns decay test, charging methods weigh-in superheat subcooling, airflow setting blower speed
CFM per ton 350-450, service troubleshooting low charge high superheat low subcooling, overcharge high subcooling, restriction, non-condensables, compressor
diagnostics, NATE Specialty exams include Air Conditioning AC Service 100 questions, AC Installation, Air Distribution, Heat Pump Service Installation, Gas Heating
Service Installation, Oil Heating, Commercial Refrigeration, Light Commercial, Efficiency Analyst, NATE certification process experience 2 years recommended, Core exam
plus Specialty, Ready to Work entry level, HVAC Support Technician, recertification 16 hours CE every 2 years, KATEs domains Safety 9 percent Tools 11 percent Basic
Construction 7 percent Basic Science 13 percent Achieving Desired Conditions 16 percent Taking Temperature Pressure 15 percent Basic Electrical 17 percent Piping
Service Installation 12 percent.
NATE HVAC Exam Domains KATEs Certification Study Guide 2026
Description: NATE HVAC Technician Certification Practice Study Guide domains based on NATE KATEs Knowledge Areas of Technician Expertise, credential NATE
Certified Technician Core plus Specialty certification recognized industry standard HVAC excellence, eligibility recommended 1-2 years field experience, Ready to Work no
experience, Core exam 100 questions, Specialty exams 100 questions 70 percent passing, exam blueprint Core: Safety 9 percent LOTO PPE, Tools 11 percent manifold
gauges vacuum pump, Basic Construction 7 percent job site, Basic Science 13 percent heat transfer gas laws, Achieving Desired Conditions 16 percent comfort
psychrometrics, Taking Temp Pressure Measurements 15 percent superheat subcooling TESP, Basic Electrical 17 percent Ohms Law capacitors motors, Piping Service
Installation 12 percent brazing evacuation, Specialty AC Service: Installation 13 percent evacuation charging, Service 46 percent diagnostics superheat subcooling
electrical, System Components 25 percent compressor TXV, Air Distribution 16 percent airflow duct, Gas Heat Service: Installation 19 percent venting gas piping, Service
48 percent sequence operation troubleshooting flame sensor ignitor, System Components 20 percent gas valve inducer, Air Distribution 13 percent temperature rise, Heat
Pump Service: Installation 16 percent reversing valve defrost, Service 43 percent defrost charge, System Components 25 percent TXV compressor, Air Distribution 16
percent balance point, study materials NATE KATEs, EPA 608, Modern Refrigeration and Air Conditioning, latest 2026/2027 based on NATE KATEs, 150 original practice
questions answers detailed solutions for NATE HVAC candidates, HVAC core electrical refrigeration airflow safety tools superheat subcooling TESP TXV capacitors defrost
gas sequence LOTO, NATE HVAC candidates exam preparation, NATE HVAC Technician Certification Examination Practice Guide, study guide borders page numbers
improved cover page educational purposes.
Page 2 - NATE HVAC Practice 150Q 2026/2027
,Question 1: Q1: What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction
pressure indicates evaporator charge prevents floodback
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction pressure indicates evaporator
charge prevents floodback - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
C. Incorrect: Confuses is with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: B. What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction
pressure indicates evaporator charge prevents floodback - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What is superheat and how is it calculated in an HVAC system? Suction line temp minus saturation temp at suction pressure indicates evaporator charge
prevents floodback - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC
technician certification original practice.
Question 2: Q2: What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured
saturation liquid minus liquid line
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses does with unrelated system component and wrong measurement method
C. What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured saturation liquid minus liquid line -
detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: C. What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured
saturation liquid minus liquid line - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What does a high subcooling reading indicate in AC system? Overcharge restriction condenser flooding measured saturation liquid minus liquid line - detailed
explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification original
practice.
Question 3: Q3: What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant
superheat sensing bulb
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses is with unrelated system component and wrong measurement method
C. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
D. What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant superheat sensing bulb - detailed
explanation per NATE KATEs Knowledge Areas of Technician Expertise
CORRECT ANSWER: D. What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant
superheat sensing bulb - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What is purpose of TXV Thermostatic Expansion Valve? Regulates refrigerant flow evaporator maintains constant superheat sensing bulb - detailed
explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification original
practice.
Question 4: Q4: How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer
compare rating 0.5 inch WC indicates restrictive duct dirty filter
A. How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer compare rating 0.5 inch WC indicates
restrictive duct dirty filter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
B. Incorrect: Misinterpretation of How leading to wrong diagnostic and unsafe practice per NATE
C. Incorrect: Confuses do with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for How
CORRECT ANSWER: A. How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer
compare rating 0.5 inch WC indicates restrictive duct dirty filter - detailed explanation per NATE KATEs Knowledge Areas of Technician
Expertise
RATIONALE:
Rationale: How do you calculate total external static pressure TESP? Sum supply plus return static measured manometer compare rating 0.5 inch WC indicates restrictive
duct dirty filter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician
certification original practice.
Question 5: Q5: What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor
glows gas valve opens flame sensor proves blower on safeties
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor glows gas valve opens flame
sensor proves blower on safeties - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
C. Incorrect: Confuses is with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: B. What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor
glows gas valve opens flame sensor proves blower on safeties - detailed explanation per NATE KATEs Knowledge Areas of Technician
Expertise
RATIONALE:
Rationale: What is correct sequence for checking gas furnace wont heat? Thermostat call inducer pressure switch closes ignitor glows gas valve opens flame sensor
proves blower on safeties - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC
technician certification original practice.
Page 3 - NATE HVAC Practice 150Q 2026/2027
, Question 6: Q6: What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand
reverses refrigerant heats outdoor coil auxiliary heat
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses causes with unrelated system component and wrong measurement method
C. What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand reverses refrigerant heats outdoor
coil auxiliary heat - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: C. What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand
reverses refrigerant heats outdoor coil auxiliary heat - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What causes heat pump to go into defrost and how does defrost work? Frost outdoor coil time-temperature demand reverses refrigerant heats outdoor coil
auxiliary heat - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician
certification original practice.
Question 7: Q7: What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run
lower failure hum no start test meter
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses is with unrelated system component and wrong measurement method
C. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
D. What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run lower failure hum no start test
meter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
CORRECT ANSWER: D. What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run
lower failure hum no start test meter - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: What is function of capacitor in HVAC systems? Stores energy phase shift start run PSC motors start high MFD run lower failure hum no start test meter -
detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification
original practice.
Question 8: Q8: How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed
evaporator iced blower speed static pressure high
A. How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed evaporator iced blower speed static
pressure high - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
B. Incorrect: Misinterpretation of How leading to wrong diagnostic and unsafe practice per NATE
C. Incorrect: Confuses do with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for How
CORRECT ANSWER: A. How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed
evaporator iced blower speed static pressure high - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
RATIONALE:
Rationale: How do you troubleshoot low airflow residential split system? Check filter dirty blower wheel dirty duct closed evaporator iced blower speed static pressure high
- detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC technician certification
original practice.
Question 9: Q9: What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to
Work HVAC Support Gas Heat Heat Pump AC Service KATEs 2 years recert 2 years
A. Incorrect: Misinterpretation of What leading to wrong diagnostic and unsafe practice per NATE
B. What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to Work HVAC Support Gas Heat
Heat Pump AC Service KATEs 2 years recert 2 years - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
C. Incorrect: Confuses is with unrelated system component and wrong measurement method
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for What
CORRECT ANSWER: B. What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to
Work HVAC Support Gas Heat Heat Pump AC Service KATEs 2 years recert 2 years - detailed explanation per NATE KATEs Knowledge Areas
of Technician Expertise
RATIONALE:
Rationale: What is NATE certification process and KATEs? North American Technician Excellence Core plus Specialty Ready to Work HVAC Support Gas Heat Heat
Pump AC Service KATEs 2 years recert 2 years - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct
troubleshooting for HVAC technician certification original practice.
Question 10: Q10: Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter
discharge capacitors PPE 24V high voltage 120/240/480 OSHA
A. Incorrect: Misinterpretation of Electrical leading to wrong diagnostic and unsafe practice per NATE
B. Incorrect: Confuses safety with unrelated system component and wrong measurement method
C. Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter discharge capacitors PPE 24V high
voltage 120/240/480 OSHA - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise
D. Incorrect: Recommends unsafe shortcut that violates EPA 608 and NATE safety standards for Electrical
CORRECT ANSWER: C. Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter
discharge capacitors PPE 24V high voltage 120/240/480 OSHA - detailed explanation per NATE KATEs Knowledge Areas of Technician
Expertise
RATIONALE:
Rationale: Electrical safety HVACR what are LOTO and safe practices? Lockout Tagout disconnect power test voltmeter discharge capacitors PPE 24V high voltage
120/240/480 OSHA - detailed explanation per NATE KATEs Knowledge Areas of Technician Expertise. Per NATE KATEs this is correct troubleshooting for HVAC
technician certification original practice.
Page 4 - NATE HVAC Practice 150Q 2026/2027
