NOCTI Heating, Ventilation, and Air Conditioning (HVAC) Practice Test

These questions are part of the practice quiz. Start practicing

• In electrical circuits, the _____ wire protects the operator.
• The refrigerant vapor picks up additional heat as it flows from the evaporator to the compressor. The heat is picked up from the ______.
• If F equals 32, what is Celsius?
• What Btu of heat is required to raise 1 pound of steam 1 degree F above the temperature of 212 degrees F?
• Heat flows from warmer substance to a cooler substance.
• The study of air and its properties is called what?
• Vaporization can be increased by which action on a liquid?
• What is the cylinder color code for R-502?
• A 14-gauge solid copper wire used in a general circuit should be protected by a fuse or breaker rated at how many amperes?
• The dial-type meter used to measure the pressure in a heating unit's flue pipe is called a
• Flame retention oil burners have what effect on flame temperature compared with conventional burners?
• What is the easiest way to move equipment across a roof?
• Under standard atmospheric conditions for water to boil at 212°F, which statement is correct?
• The compressor's main function is to
• Which statement about capacitors is true?
• A fusible plug is made from
• CSST gas tubing is compatible with which gas equipment?
• What Btu of heat is required to raise 1 pound of ice 1 degree F when the temperature is below 32 degrees F?
• According to the source, which element is said to have the highest melting point?
• One chlorine atom can destroy how many ozone molecules?
• Which formula is used to convert Fahrenheit to Celsius?
• A psychrometer is used to measure which property of air?
• Initiation of defrost in a heat pump system can be done by which of the following methods?
• Which statement best describes latent heat?
• What is the purpose of the metering device in a vapor compression system?
• What is the tool used to create external threads on a pipe?
• What is the pressure on the high pressure side of a mechanical refrigeration unit called?
• Which statement about metering devices is true?
• What are the three components required for combustion?
• What is the safest method to move heavy equipment across a roof?
• Flame retention oil burners produce a flame that is how many degrees Fahrenheit hotter than conventional burners?
• What is the best tool to open and close the stem access valve on a refrigeration system?
• Which condition occurs in the evaporator?
• Enthalpy describes what?
• In an air conditioning and refrigeration system, what occurs in a condenser?
• Excessive subcooling in a system is typically caused by operating in what condition?
• Which refrigerant is historically associated with older central air systems and is a CFC?
• Which statement is true about the state of matter?
• Residential air conditioning systems have a normal superheat range of how many degrees under normal operating conditions?
• Latent heat is measured in which unit?
• Which component rejects heat from the refrigerant to outdoor air in heating mode?
• In a typical vapor compression system, where is liquid refrigerant stored before expansion?
• Slips and drives are used in a metal duct system to perform which function?
• The three states of matter are
• Which hydrocarbon constitutes the largest share of natural gas?
• Which refrigerant is used in smaller centrifugal compressors?
• A two-ton air conditioning system has a capacity of approximately how many BTU per hour?
• When writing a resume, it’s best to
• Opposition to the flow of alternating current in an AC circuit is called what?
• When pressure testing a completed copper tubing assembly with pressurized nitrogen cylinders, this should ______.
• Which component moves refrigerant through the system?
• At the outlet of the condenser, the refrigerant is typically in which state?
• The reason subcooling would be below 8 degrees on an air conditioning system is due to which condition?
• The cylinder color for R-22 is?
• Which plan provides the layout of rooms and interior features that helps place walls and ducts?
• Scroll compressors are cooled by
• In a 24-volt circuit with a switch and a coil, what voltage will appear across the coil when the switch is closed?
• During leak testing of refrigerant piping, what is a key reason to avoid deep vacuum testing?
• When troubleshooting an air conditioning system, the operating pressures are 40 psig on the low side and 116 psig on the high side. What is the most likely problem?
• Latent heat describes which of the following?
• Which PPE should a sheet metal worker wear when working with sharp or rough metal?
• In ductwork, slips and drives are used to do what?
• A sub-base of a thermostat should be mounted in which orientation?
• Maintenance on an oil boiler or furnace is recommended how often?
• Water on the floor increases the risk of which hazards in a work area?
• In a sealed system, pressure and temperature do what?
• How often should the oil in a vacuum pump be changed?
• Which measurement is typically recorded on the service invoice during preventive maintenance?
• Which statement about wearing rubber-soled, steel-toed boots is true?
• The ignition method that uses an electric spark to ignite the pilot is called the
• What happens to the refrigerant pressure when it passes through the compressor?
• The high pressure side pressure is sometimes called discharge pressure or which other term?
• CSST connections are compatible with both natural gas and propane gas equipment.
• After the condenser, the refrigerant is typically in which state and moves to which component?
• Which ignition method uses a spark to ignite the pilot?
• One ton of cooling requires how many CFM of air flow?
• At standard conditions, water boils at what temperature in Celsius?
• For complete combustion in a boiler or furnace to occur, which elements must be present?
• CSST connections can be used with which gas equipment?
• One BTU is the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit.
• In HVAC practice, which type of heat exchange system uses the earth as a heat source or sink?
• Which organization requires approved footwear on job sites?
• Which safety benefit is provided by rubber-soled, steel-toed boots?
• A day-ton of refrigeration is defined as the amount of refrigeration produced by melting 1 ton of ice at 32°F in 24 hours.
• In combustion, which component acts as the oxidizer?
• If a 14-gauge copper conductor is protected by a breaker rated lower than its ampacity, what is the most important reason for this protection rating?
• Two gases that considered non-condensable in a refrigeration
• The best tool to open and close the system access valve on a refrigeration system is the ______.
• When heated, a thermocouple generates which type of electrical signal?
• What is the amount of heat energy required to evaporate 1 pound of water?
• Which instrument uses dry-bulb and wet-bulb temperatures to determine humidity?
• Under standard conditions, water boils at 212°F at what pressure?
• Non-double-insulated power tools must use what kind of plug?
• How far should a ladder extend above a landing surface?
• 200°F converted to Celsius equals approximately
• Which component rejects both sensible and latent heat from the refrigeration system?
• When troubleshooting an air conditioning system and you notice frost on the suction line, what would be the problem?
• Which of the following is NOT a condition of low superheat on an air conditioning system?
• In what year did venting CFC and HCFC refrigerants become unlawful?
• a gas law that states the total pressure of a combined mixture is equal to the sum of the individual pressures is
• What is the primary function of the refrigerant compressor in a vapor-compression cycle?
• Water on the floor in the work area increases the risk of which hazards?
• When ascending into the atmosphere, atmospheric pressure decreases by 1 psi for every
• Which safety device is made from a metal alloy that burns when overheated?
• Which of the following is NOT a health risk associated with ozone depletion?
• A Bourdon tube is often found in a
• Connections should be permanently connected with_____ on drainage piping assemblies that uses PVC piping
• The statement “The exertion of pressure on a substance at constant temperature increases its volume in proportion to the increase in pressure” is:
• Which statement about purging copper tubing during brazing is correct?
• The condenser's primary function is
• When fighting a fire involving oily rags, which type of extinguisher is appropriate?
• What is the primary purpose of the thermostat sub-base?
• If a heat pump's reversing valve fails to switch between heating and cooling modes, which component is most likely defective?
• When a gas furnace is not functioning and shows a lockout on the circuit board, what is the recommended method to reset the Integrated Furnace Controller (IFC)?
• In a refrigeration system, which gases are considered non-condensables?
• Which pipe material is commonly used for condensation drainage due to its resistance to corrosion and ease of installation?
• Which device is essential when pressurizing nitrogen for a leak test on copper tubing?
• When reading blueprints for proper wall and duct location, the technician should look at the ______.
• Evacuating a system is accomplished with an _____ and helps to remove air and non-condensables in HVAC/R applications.
• If a device operates at 120 volts and draws 4 amperes, its power consumption is?
• A one-ton air conditioning system provides how many BTU per hour?
• What occurs in an evaporator of a refrigeration system?
• In the refrigeration cycle, what device increases the pressure of the refrigerant?
• In HVAC systems, which device is used to reject latent heat from the refrigerant?
• Which instrument typically houses a Bourdon tube?
• Which color code is associated with R-502?
• The ______ is referred to as kinetic displacement compressor.
• Which statement about metering devices is true?
• In some heat pump defrost-control schemes, which component monitors conditions to start defrost?
• Which term is not a standard method of heat transfer?
• The type of pipe commonly used for condensation drainage on central air conditioning system is
• Which hydrocarbon makes up the largest percentage of natural gas?
• Latent heat effects are associated with which of the following?
• In heat loss calculations, HTM stands for which term?
• Bad ozone is found in which atmospheric layer?
• In a refrigeration system, the refrigerant enters the condenser as a
• The cause for excessive subcooling in an air conditioning system?
• If 1 pound of water is warmed from 55°F to 60°F, how many BTUs are absorbed?
• How many pressure levels does every mechanical refrigeration system have?
• What is the angle of the shoulder?
• In the real power formula P = V × I × PF, what does PF represent?
• A pressure reading of 10 inches water column is approximately equal to how many psig?
• What is the boiling point of water in Fahrenheit?
• Which type of oil is used in modern automotive air conditioning systems?
• Refrigeration can be described as
• Reciprocating compressors have which components?
• Which term is used for pressure in the metric system?
• During a routine preventive maintenance call, which measurement should be recorded on the service invoice?
• Which hydrocarbon is the primary component of natural gas?
• Rubber-soled, steel-toed boots help prevent injuries involving which hazards?
• To prevent falls from high working conditions, a technician should use which safety system?
• Fires that involve ordinary materials such as paper, cardboard, and wood are classified as Type _____ fires.
• Incomplete combustion produces
• If the low-side pressure is 90 psi and the high-side is 250 psi, what is the most likely problem?
• R-22 refrigerant is color coded as which color on labeling?
• Electrical power should always be shut off at the service disconnect or entrance panel when installing equipment. What is the correct term for this shut-off point?
• Leak checking refrigerant piping when it is in deep vacuum should be avoided because which condition could be pulled into the circuit?
• A 50/50 solder is a combination of lead and which metal?
• Which device is used to measure the amount of CO2 in flue products?
• The four major components of a vapor compression refrigeration system are the compressor, condenser, evaporator, and ______.
• Using oxygen to purge copper tubing after brazing could cause an explosion.
• Which refrigerant type has the largest temperature glide?
• What year did it become necessary for HVAC technicians to become certified to handle refrigerants under Section 608 of the Clean Air Act?
• Capacitors are rated in which two quantities?
• The PSIA at sea level under standard conditions is _____ psi.
• Which refrigerant type is noted for very low Global Warming Potential among common options?
• A metric term for pressure is
• In a heat pump designed for both heating and cooling, which device changes the flow of the refrigerant for each mode?
• Fires that involve electrical equipment are classified as Type _____ fires.
• Which power tool is best to cut steel rod?
• What is the process of removing refrigerant from an air conditioning system and storing it in an external container called?
• R-22 is a refrigerant most commonly used in ________ systems.
• What is the angle of the shoulder as given in the material?
• Dalton's law pertains to which concept?
• When pressure testing completed copper tubing assembly with pressurized nitrogen the nitrogen cylinder should
• An HVAC system that depends on the temperatures below the ground surface as an operation factor is a/an______?
• From a performance standpoint, a substitute for R-12 is ______.
• A solder composition of 50/50 indicates the alloy is composed of lead and tin in what proportion?
• Which color is used to identify R-22 on labeling?
• Which tool is used to check the gas pressure in a refrigeration system?
• In a 120-volt AC circuit drawing 5 amps, what is the power in watts?
• After brazing a joint in a very tight location, which instrument would be used to determine if the joint is properly brazed?
• Which of the following is NOT a major component of a vapor compression refrigeration system?
• Which statement is true regarding the use of nitrogen for pressure testing copper tubing?
• Which materials are used for non-conductive ladders?
• Which HVAC system uses underground temperatures as an operating factor?
• Which of the following is not a type of compressor?
• Which factor is used to compare refrigerants and their environmental impact?
• Which device maintains boiler pressure around 10 to 15 psi in the system?
• External threads on pipes are cut with which tool?
• What is the typical boiler system pressure range maintained by an automatic fill valve?
• How should horizontal refrigerant lines be pitched to ensure proper operation?
• Internal threads are cut with which tool?
• Which is not a method by which heat may be transferred from a warmer substance to a colder substance?
• Oil must never be used around a ______ cylinder.
• In a sealed refrigeration system, which two properties tend to rise and fall together?
• What is the tool used to create internal threads?
• In electrical safety, which plug type is required for tools that are not double-insulated?
• In a condenser, the refrigerant changes from vapor to liquid as heat is removed.
• 200 degrees Fahrenheit converted to Celsius equals approximately
• In a vapor compression refrigeration system, which component increases the refrigerant pressure?
• Sensible heat describes which of the following?
• Fires involving electrical equipment are classified as Type _____ fires.
• What is the most commonly known CFC refrigerant?
• In the formula P = V × I × PF, what does PF stand for?
• HTM stands for Heating Transfer Multiplier.
• Non-conductive ladders are typically made from which materials?
• What is the permanent storage device found inside a desktop computer?
• Which refrigerant is commonly associated with small centrifugal compressors, per the source?
• The ozone layer that protects living organisms from ultraviolet radiation is located in which atmospheric layer?