Download NATE HVAC Certification Exam 2025 Prep – Air Conditioning & Heat Pump: Complete Q&A Study and more Exams Engineering in PDF only on Docsity!
NATE HVAC Certification Exam 2025 Prep-
Air Conditioning & Heat Pump — Complete
Q&A Study Guide (Verified Questions &
Answers)
What can listening carefully to a customer help you with? - CORRECT ANSWER Diagnose the problem Customers depend on you to be patient, loyal and? - CORRECT ANSWER Honest Using a (BLANK) can cut hard or soft copper, leave no metal shavings to contaminate the system and produce a clean, square cut. - CORRECT ANSWER Tube cutter In discussing human comfort, the temperature most commonly referred to is? - CORRECT ANSWER Dry-bulb A sling psychrometer uses two glass-stem thermometers. One measures dry-bulb and the other measures? - CORRECT ANSWER Wet-bulb What agency regulates cylinders and chemicals transported in a service vehicle? - CORRECT ANSWER DOT Which of the following classifications of fire extinguishers should be used for electrical fires? - CORRECT ANSWER Class C When using a ladder. you should always? - CORRECT ANSWER Maintain three points of contact When does a ground fault circuit interrupter open an electrical circuit? - CORRECT ANSWER When current travels through a ground path other than the normal neutral A natural cooling process produced by moisture on the skin changing to low-pressure steam is called? - CORRECT ANSWER Evaporation During the heating season, human comfort can be enhanced without changing the temperature of the air by? - CORRECT ANSWER Adding moisture
During the cooling season, dampers on bypass humidifiers should be? - CORRECT ANSWER Completely closed Stored energy is called (BLANK) energy. - CORRECT ANSWER Potential Heat that you can feel and measure directly with a thermometer is called? - CORRECT ANSWER Sensible heat The heat energy change associated with a phase (state) change is called? - CORRECT ANSWER Latent heat The amount of heat (BTU) needed to raise the temperature of 1 lb of a substance 1 degree F is called the (BLANK) heat of a substance. - CORRECT ANSWER Specific At 32 degrees F, 1 lb of ice can be changes to 1 lb of water by adding (BTU). - CORRECT ANSWER 144 When liquid and vapor phases of a substance exist together, and no more liquid can vaporize without more energy being added, the vapor is said to be? - CORRECT ANSWER Saturated When a vapor is heated to a temperature higher than its saturation point, both the added heat and the temperature above saturation are called? - CORRECT ANSWER Superheat The process of molecules escaping from the surface of a liquid is called? - CORRECT ANSWER Evaporation The process of a solid turning directly into a vapor without going through the liquid state is called? - CORRECT ANSWER Sublimation The continuous movement of molecules within a liquid or gas is called? - CORRECT ANSWER Kinetic energy Enthalpy includes both (BLANK) and (BLANK) heat energy. - CORRECT ANSWER Latent and sensible
How many functions is an individual circuit in a control system designed to control? - CORRECT ANSWER One The five basic components common to all schematics are a power supply, a path, load, a legend and a? - CORRECT ANSWER Switch The type of schematic that provides the most helpful troubleshooting information for the service technician is the (BLANK) diagram? - CORRECT ANSWER Ladder Devices that consume power and convert it to some other form of energy, such as motion or heat are? - CORRECT ANSWER Loads The normal dividing line for voltage changes in a schematic is the? - CORRECT ANSWER Transformer The part of a schematic that lists and explains the system components is called the? - CORRECT ANSWER Legend When testing with a voltmeter, you should place the meter? - CORRECT ANSWER In parallel with the circuit being tested When you use an ohmmeter, the circuit being measured must be? - CORRECT ANSWER Isolated from all energy sources When using a standard clamp-on ammeter, you should (BLANK) before taking a reading. - CORRECT ANSWER Make sure that the jaws are closed Capacitance meters must be used on capacitors that? - CORRECT ANSWER Have been removed from the circuit When testing a thermostat wire that has been removed from the circuit, you measure 0 ohms between red and white. This indicates? - CORRECT ANSWER There is a short When testing with a ammeter, you should place the meter? - CORRECT ANSWER In series with the circuit being tested d (very important) - CORRECT ANSWER The ability to utilize all types of communication skills is ____ to the HVACR technician. a. not as important as "hands-on" technical skills
b. somewhat important c. unimportant d. very important d (all of the above: clear, complete, concise) - CORRECT ANSWER It is important to be ____ in filling out service orders so that office staff, other technicians, and customers will know what work you completed on the job. a. clear b. complete c. concise d. all of the above d (Refrigerant) - CORRECT ANSWER When explaining to a customer that you have adjusted the system charge, which of the following terms is most appropriate? a. Freon b. Gas c. Juice d. Refrigerant a (can help you diagnose the problem) - CORRECT ANSWER Listening carefully to what a customer is telling you ____. a. can help you diagnose the problem b. is a waste of time c. is not necessary d. often will only confuse you b (listen to the customer first, then ask questions) - CORRECT ANSWER When you arrive at a service call and meet the customer, you should ____. a. ask questions first, then listen to what the customer has to say b. listen to the customer first, then ask questions c. avoid discussion with the customer d. remind the customer that you are the professional and get on with your work b (1,600 ft3) - CORRECT ANSWER What is the volume of a room that measures 10 ft by 20 ft with an 8-ft ceiling? a. 800 ft
d (1,800 ft/min) - CORRECT ANSWER How fast does air with a velocity pressure of 0.20 in w.g. move through a square duct? a. 400 ft/min b. 1,200 ft/min c. 1,600 ft/min d. 1,800 ft/min Note: Velocity = 4005 x (the square root of velocity pressure) d (all of the above: honest, loyal, patient) - CORRECT ANSWER Customers depend on you to be ____. a. honest b. loyal c. patient d. all of the above c (demonstrate system operation and describe basic maintenance procedures to the customer) - CORRECT ANSWER Before leaving a service call, you should be sure to ____. a. ask the customer for referrals b. collect payment in cash if possible c. demonstrate system operation and describe basic maintenance procedures to the customer d. try to sell the customer an equipment upgrade d (All of the above: it can cut hard or soft drawn copper; it leaves no metal shavings to contaminate the system; it produces a clean, square cut.) - CORRECT ANSWER What is the advantage of using a tube cutter to cut copper pipe? a. It can cut hard or soft drawn copper b. It leaves no metal shavings to contaminate the system c. It produces a clean, square cut d. All of the above a (soft drawn copper) - CORRECT ANSWER Spring-type benders may be used on ____. a. soft drawn copper
b. hard drawn copper c. all copper pipe d. steel pipe a (make a mechanical joint in tubing) - CORRECT ANSWER A flaring tool is used to ____. a. make a mechanical joint in tubing b. measure pipe diameters c. remove burrs from piping d. solder tubing without the use of coupling d (solder tubing without the use of couplings) - CORRECT ANSWER A swaging tool is used to ____. a. cut copper tubing b. make a mechanical joint in tubing c. remove burrs from piping d. solder tubing without the use of couplings a (It is very accurate) - CORRECT ANSWER What is one of the advantages of a glass-stem thermometer? a. It is very accurate b. It is very durable c. It comes with a digital readout d. Non of the above b (dry-bulb) - CORRECT ANSWER In discussing human comfort, the temperature most commonly referred to is ____. a. dew point b. dry-bulb c. wet-bulb d. Fahrenheit d (wet-bulb) - CORRECT ANSWER A sling psychrometer uses two glass-stem thermometers. One measures dry-bulb, and the other measures ____. a. dew point b. enthalpy
a (Recovery machine) - CORRECT ANSWER To prevent the release of refrigerant to the atmosphere while removing it from a system, what type of equipment must be used? a. Recovery machine b. Recycling machine c. Reclaim machine d. Vacuum pump b (air velocity) - CORRECT ANSWER An anemometer uses a small fan blade to measure ____. a. air pressure b. air velocity c. air volume d. static pressure c (No flux is required) - CORRECT ANSWER What is one of the advantages of using silver brazing rods for copper-to-copper joints? a. A lower melting temperature is required b. A propane torch is normally used c. No flux is required d. No nitrogen purge is needed d (all of the above) - CORRECT ANSWER "Housekeeping" includes ____. a. disposal of waste b. fire prevention and protection c. proper storage of materials d. all of the above b (Goggles) - CORRECT ANSWER What type of eye protection should you wear when drilling overhead? a. Face shield b. Goggles c. Side shields d. Spectacles
b (DOT) - CORRECT ANSWER What agency regulates cylinders and chemicals transported in a service vehicle? a. ASHRAE b. DOT c. EPA d. OSHA a (contain information about personal protective equipment) - CORRECT ANSWER Material safety data sheets ____. a. contain information about personal protective equipment b. do not provide recommendations regarding emergency procedures c. should be kept in a safe place off-site d. should be read after any chemical products have been used d (Never) - CORRECT ANSWER When should oxygen be used in a refrigeration system? a. To clear a restriction in the line b. To pressurize for leak-testing c. To purge lines for brazing d. Never c (Class A is an "ordinary" fire that involves the burning of wood, paper, or textile products, extinguishing agent: water. Class B is a fire that contains oil, grease, paint, varnish, or other chemicals, extinguishing agent: foam. Class C is an electrical fire, extinguishing agent: carbon dioxide.) - CORRECT ANSWER Which of the following classifications of fire extinguishers should be used for electrical fires? a. A b. B c. C d. D d (All of the above: asphyxiating, flammable, toxic) - CORRECT ANSWER Which of the following categories could be considered a hazardous atmosphere in a confined space? a. Asphyxiating b. Flammable
b. When the circuit is overloaded c. When there is a short circuit d. All of the above b (only by the person who installed the locks) - CORRECT ANSWER Proper lockout/tagout procedures state that locks placed on a lockout device may be removed ____. a. by anyone on the job site b. only by the person who installed the locks c. only after all fuses have been replaced d. only when the equipment is grounded c (evaporation) - CORRECT ANSWER A natural cooling process produced by moisture on the skin changing to low-pressure steam is called ____. a. conduction b. convection c. evaporation d. radiation a (adding moisture) - CORRECT ANSWER During the heating season, human comfort can be enhanced without changing the temperature of the air by ____. a. adding moisture b. reducing moisture c. increasing air filtration d. increasing air speed a (completely closed) - CORRECT ANSWER During the cooling season, dampers on bypass humidifiers should be ____. a. completely closed b. completely open c. set at 25% d. set at 50% d (all of the above: liquid, solid, gas) - CORRECT ANSWER All matter can exist as a ____. a. liquid
b. solid c. gas d. all of the above c (potential) - CORRECT ANSWER Stored energy is called ____ energy. a. controlled b. kinetic c. potential d. quantum c (sensible) - CORRECT ANSWER Heat that you can feel and measure directly with a thermometer is called ____ heat. a. absolute b. latent c. sensible d. super b (latent) - CORRECT ANSWER The heat energy change associated with a phase (state) change is called ____ heat. a. absolute b. latent c. sensible d. super d (specific) - CORRECT ANSWER The amount of heat (Btu) needed to raise the temperate of 1 lb of a substance 1°F is called the ____ heat of the substance. a. absolute b. latent c. sensible d. specific b (liquid, solid) - CORRECT ANSWER The latent heat of fusion is the amount of energy required to change 1 lb of a substance from the ____ phase to the ____ phase without changing its temperature. a. liquid, vapor b. liquid, solid
b. evaporation c. saturation d. subcooling c (sublimation) - CORRECT ANSWER The process of a solid turning directly into a vapor without going through the liquid state is called ____. a. saturation b. subcooling c. sublimation d. superheating b (kinetic) - CORRECT ANSWER The continuous movement of molecules within a liquid or gas is called ____ energy. a. atomic b. kinetic c. potential d. stored a (latent, sensible) - CORRECT ANSWER Enthalpy includes both ____ and ____ heat energy. a. latent, sensible b. latent, specific c. sensible, specific d. specific, absolute d (weight) - CORRECT ANSWER The measurement of the force that gravity exerts is called ____. a. mass b. specific matter c. volume d. weight b (mass) - CORRECT ANSWER The amount of matter in a substance is called ____. a. gravity b. mass c. volume
d. weight a (density) - CORRECT ANSWER Weight per unit volume or mass per unit of volume is called ____. a. density b. specific gravity c. specific mass d. specific volume d (specific volume) - CORRECT ANSWER Volume per unit of mass or weight is called ____. a. density b. specific gravity c. specific mass d. specific volume c (0.075 lb/ft3) - CORRECT ANSWER Under standard conditions, air weighs approximately ____ lb/ft3. a. 0.055 lb/ft b. 0.065 lb/ft c. 0.075 lb/ft d. 0.085 lb/ft d (86°) - CORRECT ANSWER Solve to find the Fahrenheit temperature corresponding to 30°C. a. 32° b. 68° c. 70° d. 86° Note: 32°F = 0°C. 9/5°F = 1°C. °F = (9/5 x °C) + 32 °C = (°F - 32) x 5/ b (68°) - CORRECT ANSWER Solve to find the Fahrenheit temperature corresponding to 20°C. a. 32° b. 68° c. 70°
b. 1.2 ft c. 2.0 ft d. 3.0 ft Note: Vf = Vi x (Tf / Ti) T = °F + 460 c (44.7 psia) - CORRECT ANSWER If gauge pressure reads 30 psi, what is the corresponding absolute pressure? a. 15.7 psia b. 34.7 psia c. 44.7 psia d. 60.7 psia c (Dalton's) - CORRECT ANSWER The law that applies to the total pressure exerted by a mixture of gases or vapors is called ____ Law. a. Boyle's b. Charles' c. Dalton's d. Newton's d (6.28 x 10^18) - CORRECT ANSWER A coulomb is a charge of ____ electrons. a. 6. b. 628 c. 628 Million d. 6.28 x 10^ b (electron flow) - CORRECT ANSWER An ampere is a measurement of ____. a. electrical charge b. electron flow c. opposition to current d. potential energy b (force that moves electrons through a circuit) - CORRECT ANSWER Voltage is best described as the ____. a. amount of power being used in a circuit
b. force that moves electrons through a circuit c. magnetic field surrounding a conductor d. resistance to the flow of electrons b (resistance) - CORRECT ANSWER Current in a circuit is limited by ____. a. heat b. resistance c. temperature d. voltage a (conductor) - CORRECT ANSWER A substance that permits the free movement of electrons is called a(n) ____. a. conductor b. insulator c. resistor d. semiconductor c (A short, large-diameter conductor) - CORRECT ANSWER Which of the following conductors would have the least resistance? a. A long, large-diameter conductor b. A long, small-diameter conductor c. A short, large-diameter conductor d. A short, small-diameter conductor c (double) - CORRECT ANSWER If the voltage in a circuit is doubled and the resistance remains the same, the current will ____. a. drop to zero b. be cut in half c. double d. stay the same d (25 V) - CORRECT ANSWER What is the voltage of a circuit if the resistance is 5Ω and the current is 5 A? a. 1 V b. 2.5 V c. 10 V d. 25 V
