Air Conditioning Certification (A-02) Practice Exam

These questions are part of the practice quiz. Start practicing

• What is an air conditioning load calculation?
• What is required before using an electronic leak detector?
• What commonly causes short-cycling in an AC system?
• What is the correct sequential order of steps in the vapor-compression process?
• If an air conditioning system does not cool properly while running continuously, what should be one of the first areas to check?
• What is one of the main functions of a condenser in an air conditioning system?
• What is the purpose of a return air duct in an air conditioning system?
• Which practice is important when using refrigerant recovery equipment?
• How does an evaporator coil function in an AC system?
• How do extremely high outdoor temperatures affect air conditioning systems?
• What is the purpose of a thermostatic expansion valve in an air conditioning system?
• A temperature change across a filter-drier indicates what?
• How many operating pressures does a thermostatic expansion valve have?
• Which method can be used to defrost a low temperature evaporator?
• In terms of air conditioning maintenance, how often should filters ideally be changed?
• Why are maintenance records important for air conditioning systems?
• What does zero psig (pounds per square inch gauge) indicate?
• Why is proper insulation important for an air conditioning system?
• What factor is essential for maintaining efficiency in an air conditioning cycle?
• What symptoms can a dirty evaporator cause in an air conditioning system?
• What is the term for heat that causes a change in temperature of a substance?
• What is a common symptom indicating a refrigerant leak in an AC system?
• What is a potential issue caused by an oversized air conditioning system?
• In a refrigeration cycle, what must be done after the refrigerant is de-superheated?
• A liquid line filter-drier should be placed where?
• What symptom indicates a hermetic system that is low on charge?
• What is the name for the temperature at which moisture starts to condense from the air?
• What is the purpose of a low pressure cut off switch?
• An accumulator is used to prevent what from reaching the compressor?
• What would cause frost to form on the evaporator coil?
• What is the primary role of ductwork in an air conditioning system?
• What types of heat does the condenser remove from the refrigerant?
• What does thermal load refer to?
• What can result from poor airflow due to incorrectly sized ductwork?
• What can be used for leak detection that is safe with all refrigerants?
• What formula can be used to estimate the horsepower required for an AC compressor?
• What can moisture in a refrigerant system cause?
• Why is it important for only liquid refrigerant to enter the expansion valve?
• Why is it desirable for refrigerant in the suction line to be slightly superheated?
• A rise in evaporator pressure causes the automatic expansion valve to?
• What type of heat measurement is used to quantify energy changes in heating and cooling processes?
• What condition does a system's high head pressure indicate?
• When faced with a "no cooling" complaint, what method can a technician use to pressurize the system?
• An increase in head pressure causes how much refrigerant to flow through a capillary tube?
• What symptom is associated with a low refrigerant charge in an air conditioning system?
• When refrigerant R12 vapor leaves the condenser at 80°F, what is its approximate pressure if it entered at 116.9 psig?
• What effect does a detached TXV sensor bulb have on an air conditioning system?
• What is a critical characteristic of condensation in the refrigeration cycle?
• What is the maximum amount the refrigerant condensing temperature should exceed the entering air temperature in an air cooled condenser?
• What is the definition of refrigerant recycling?
• What does the acronym BTU stand for in relation to air conditioning?
• What is the primary purpose of an evaporator pressure regulating valve (EPR)?
• What is a common sign of a low refrigerant charge in a system?
• What is the purpose of refrigerant gauges in HVAC maintenance?
• Which of the following maintenance activities can help extend the life of an air conditioning system?
• What happens to the refrigerant when it reaches the condenser?
• What is the function of a liquid-to-suction heat exchanger?
• What does a clear sight glass usually indicate in a refrigeration system?
• Which characteristic is important for a refrigerant used in low ambient conditions?
• What does refrigerant reclaiming involve?
• Where is a sight glass typically located in a refrigeration system?
• To remove as much moisture as possible from a refrigerant system, what should be done?
• What happens when the refrigerant in an AC system is superheated?
• After a compressor replacement, if the evaporator appears starved of refrigerant and the liquid line is sweating, what is likely the cause?
• What is the first function a condenser must perform with the refrigerant before condensing can occur?
• If a system is found to have a leak, what should be the next step?
• Pressures lower than atmospheric are measured in which of the following?
• How can a technician identify refrigerant leaks in an AC system?
• What is refrigerant, and why is it important?
• A liquid receiver is used for what purpose?
• How does an oil pressure safety switch operate?
• What is a common sign of a dirty condenser coil in an air conditioning system?
• Which type of gauge is used to measure a vacuum of 500 microns?
• What type of leak detector is commonly used in refrigerant systems?
• What role does cleaning the coils play in maintaining an AC system?
• What is the most probable cause of noise in a compressor after repairing a leak in the liquid line?
• What should be done to ensure proper operation when mounting a thermostatic expansion valve sensor bulb?
• Which of the following is NOT a symptom of a hermetic system that is low on refrigerant?
• What does a MERV rating indicate?
• What might high system pressures in a capillary tube system suggest?
• What does liquid slugging refer to in the context of compressors?
• What symptoms indicate a refrigerant overcharge in a capillary tube air conditioning system?
• What are potential health risks of poorly maintained AC systems?
• What might cause a compressor to short cycle?
• Which method does heat travel through direct contact?
• In a water cooled condenser, the refrigerant condensing temperature should not be higher than how many degrees above the leaving water temperature?
• What is an effect of fan cycling in condenser operation?
• What does the process of removing moisture from air commonly refer to in air conditioning?
• Regarding the removal of solid contaminants from a hermetic compressor motor burnout, who is correct?
• What is the basic principle of how an air conditioning system works?
• How can a condenser be operated effectively in low ambient temperature conditions?
• During a vacuum test, Technician "A" states that a compressor should pull 24" hg with 100 psig discharge pressure. Technician "B" says it should pull 26" hg to 28" hg when discharging to the atmosphere. Who is correct?
• Which of the following statements about an evaporator is NOT true?
• When is refrigerant deemed appropriate for reclamation?
• What maintenance task is recommended for ensuring the longevity of an air conditioning system?
• In a direct expansion (DX) evaporator system, the refrigerant enters the evaporator as?
• Which method is appropriate for properly calibrating an electronic leak detector?
• The automatic expansion valve is tailored for systems with what kind of load?
• A thermostatic expansion valve is primarily designed to maintain what condition?
• What is the primary difference between R-22 and R-410A refrigerants?
• What is a heat pump?
• What is subcooling in relation to refrigerant in an air conditioning system?
• Which of the following factors does NOT cause a change in compressor capacity?
• How does humidity impact the performance of an air conditioning system?
• What is the primary function of a thermostat in an air conditioning system?
• A low-side float metering device is used on which type of evaporator?
• How frequently should air conditioning filters be replaced?
• How can a technician detect a restriction in the liquid line?
• What is a critical concern when handling refrigerants during recovery?
• Which of the following is NOT a thermodynamic property of refrigerants?
• A partially clogged capillary tube can cause what condition in an air conditioning system?
• What condition does superheating refer to in the refrigeration cycle?
• An inefficient compressor is indicated by what combination of head pressure and suction pressure?
• Who is correct about testing the leak-free guarantee of a system holding a vacuum?
• What major component in a refrigeration system does the condenser help convert?
• What are typical signs that an air conditioning system may need repair?
• In many systems, why is the capillary tube soldered to the suction line?
• What is the significance of the SEER rating in air conditioning units?
• Which tools are commonly utilized for HVAC system maintenance?
• What could low operating pressures and low system amperage draw indicate in a residential split system?
• How does the clearance space in a reciprocating compressor affect its performance?
• How should the sensor probe be moved when using an electronic leak detector?
• In a refrigeration system, what is the function of the compressor?
• What is the primary function of a condenser coil in an air conditioning system?
• What should the state of refrigerant in the suction line ideally be?
• What will happen when an automatic expansion valve is used as a metering device and there is a low refrigerant charge?
• Frost on the suction line indicates what about its temperature?
• What unit is used to measure the quantity of heat in a substance?
• Which statement is true about the solenoid in a pump down refrigeration system?
• If an air conditioning system is experiencing low discharge pressure, what could be the cause?
• What could bubbles in a sight glass indicate?
• What could cause a situation where the sight glass indicates a full charge, the liquid line is hot, and the unit is cycling on internal overloads?
• When a TEV or a capillary tube is used as a metering device, what is the effect of a low charge on head pressure?
• What must be done before opening a vapor/compression system for service?
• In the evaporator, what type of heat is transferred from the refrigerated space to the refrigerant?
• What happens to compressor efficiency when the refrigerant charge is low?
• What does latent heat removal achieve in air conditioning systems?
• What are the potential consequences of undersizing an air conditioning unit?
• What is the purpose of the compressor in an air conditioning system?
• What type of reading does a compound pressure gauge provide?
• An overcharge of refrigerant in a system will typically result in what effect?
• What symptoms would air or non-condensable gases in a capillary tube system likely cause?
• If a customer complains about their air conditioning system running constantly but not cooling properly, what could be indicated by a cold suction line and a sweating compressor?
• What state does the refrigerant enter when it reaches the condenser?
• What characteristic is FALSE regarding a capillary tube metering device?
• What type of heat causes a change in state of a material without a change in temperature?
• What does sub-cooling help to prevent in a refrigeration system?
• Which of the following methods does NOT transfer heat?
• What is one of the primary reasons for performing yearly professional inspections on AC systems?
• What occurs in a refrigerant when it abstracts heat from the environment?
• Why is it crucial to maintain proper refrigerant levels in an AC system?
• Which process in refrigeration involves reducing pressure to allow for rapid cooling?
• What can cause a compressor to run hot in an air conditioning system?
• What happens to the refrigerant as it exits the condenser?
• What is a potential consequence of having a low refrigerant charge in a system?
• Why is effective condensate drainage crucial in air conditioning systems?
• What impact does changing refrigerant have on an air conditioning system?
• What does "ghost airflow" refer to in a duct system?
• What is the main function of the condenser in an air conditioning system?
• At what temperature will water vaporize in a 28 in hg vacuum?
• What condition is indicated by a compressor that is cycling on high temperature overload?
• How does proper condensate drainage promote AC system efficiency?
• How do air filters affect an air conditioning system's performance?
• If a 30-pound cylinder of reclaimed R-12 refrigerant has been stored overnight at 70°F, what should the pressure in the cylinder be approximately?
• What is the term for the heat added to a vapor after its state change?
• What is the typical temperature difference across the evaporator coil in a functioning AC system?
• If 10 lbs. of refrigerant passing through a water cooled condenser gives up 20 Btu's of heat per lb, what is the temperature of the water leaving the condenser if it enters at 80°F?
• What does the term superheat refer to in air conditioning?
• Who is correct about what it means if a system does not hold a vacuum during a standing test?
• What does HVAC stand for?
• What is a common indication of high discharge pressure in a refrigerant system?
• What safety device prevents compressor damage due to high pressure?
• What does the duct sizing method known as Manual D determine?
• In systems using a thermostatic expansion valve, the temperature of the evaporator outlet is usually?
• In a refrigeration system, what happens when the EPR valve is fully closed?
• Which method is commonly used to improve air quality in air-conditioned environments?
• When may the suction line feel very cold in a system?
• A faulty condenser fan motor will likely cause what symptoms?
• What is the definition of refrigerant recovery?
• Which term best describes the heat exchange process in forced air systems?
• Which of the following refrigeration components is responsible for absorbing heat?
• What does the acronym BTU represent in the context of air conditioning?
• When does a refrigerant give up heat?
• Which condition indicates that an air conditioning system is not operating efficiently?
• What is the primary purpose of a mechanical shaft seal in an air conditioning system?
• How does shading a home impact air conditioning effectiveness?
• What does zero psia (pounds per square inch absolute) represent?
• Which expansion valve is best suited for an air conditioning system with varying loads?
• What is one of the primary reasons for leak checking a refrigeration system?
• What happens when a compressor has a broken valve?
• What does the term "latent heat" refer to?
• When mounting a thermostatic expansion valve sensor bulb, which of the following is NOT a requirement?
• How does heat transfer occur through convection?
• What role does the expansion valve play in air conditioning?
• What is a characteristic of a split system air conditioner?
• What is the role of a filter-drier in a refrigeration system?
• What are the three basic types of condensers used in air conditioning systems?
• What is the movement of heat by way of fluid or air called?
• What are the primary components of a split air conditioning system?
• Which factor is not typically affected by high outdoor temperatures in an AC system?
• A decrease in superheat causes a thermostatic expansion valve to?