Air Conditioning (A/C) and Heating Certification Practice Test

These questions are part of the practice quiz. Start practicing

• Which type of oil can be used in an R-134a system?
• Which location is common for the accumulator in the A/C system?
• What could indicate a problem with the compressor clutch if a loud squealing noise is heard?
• Which of the following factors can influence the efficiency of an air conditioning system?
• When charging an A/C system while running, where should refrigerant be added?
• If little to no resistance is felt while operating the temperature control lever, what is the likely issue?
• Which method is commonly used to test the efficiency of heating systems?
• Which technician's statement regarding air-conditioning systems is correct?
• What is one benefit of using programmable thermostats in heating and cooling systems?
• Why is it important to have a licensed professional install HVAC equipment?
• What safety measure should be taken when working with refrigerants during maintenance?
• What does a higher Seasonal Energy Efficiency Ratio (SEER) rating indicate about an A/C system?
• What indicates that a thermostat may need replacing?
• At what temperature does refrigerant typically become a gas?
• Who is correct regarding the repair of refrigerant hoses?
• What is the maximum refrigerant charge indicated by the nameplate?
• Which component is essential for removing moisture from the air in an air conditioning system?
• Who is correct regarding the connection of suction lines in HVAC systems?
• Where is the sight glass located according to Technician A and Technician B?
• What is a potential consequence of improper refrigerant charge in an AC system?
• What is the primary function of the condenser in an A/C system?
• What does thick frost on the suction line indicate?
• What is the primary function of a compressor in an A/C system?
• What should homeowners check regularly to maintain their heating systems?
• Why is it crucial to properly size an air conditioning system for a specific space?
• What is the purpose of a defrost cycle in a heat pump?
• What is the purpose of the desiccant bag in the receiver/dryer or accumulator?
• Which type of refrigerant is commonly known for its ozone-depleting properties?
• If the blower motor does not run but receives power, what are the possible causes according to the technicians?
• What should the technician suspect if the vehicle's A/C is blowing hot air despite the compressor engaging?
• What is the primary purpose of condensate drains in an air conditioning system?
• What is the function of the expansion valve in an A/C system?
• What color wires and wire harness covers are used in hybrid vehicle A/C compressors to signify high voltage?
• If one technician repairs a leaking heater core and another replaces it, who is correct?
• How does the boiling point of a liquid change when pressure is applied?
• Frost on the outside of the receiver/dryer but not on the liquid line indicates what?
• At which component does the refrigerant reach its lowest pressure and temperature?
• The filling level of a refrigerant container should never exceed _____ percent of the container's gross weight rating.
• Which of the following cannot cause excessive heat?
• Tech A claims that evacuating an A/C system removes air and moisture, while Tech B states it removes dirt particles. Who is correct?
• How does a two-stage heating or cooling system improve indoor comfort?
• What is a common reason for reduced airflow in ducts?
• Which of the following best describes the purpose of an air filter in HVAC systems?
• What does an HVAC technician use to measure temperature and pressure?
• When replacing a typical A/C system component, the system must be discharged _____.
• What is an evaporator coil's role in air conditioning?
• What type of heating system uses gas as a fuel source?
• What is psychrometrics used for?
• Which component of an A/C system absorbs heat from the indoor air?
• What is the primary purpose of insulation in buildings?
• What is the purpose of a differential pressure switch in an HVAC system?
• What does the acronym "HVAC" stand for?
• What is the desired humidity level for optimal indoor comfort?
• What could cause a compressor clutch to chatter when the A/C is on or off?
• What could a complaint of water on the front floor carpeting, even in dry weather, indicate?
• How often should you change the filter in your A/C system?
• Heater cores with electric PTC heater strips are typically used in which type of vehicle?
• What is the most common cause of system breakdown in A/C equipment?
• Besides replacing the compressor, what other component should be replaced if the compressor has seized?
• What does a variable speed blower do?
• Which technician is correct about the state of refrigerant after it leaves the compressor?
• What does a furnace's AFUE rating measure?
• What does R-value measure?
• What is the recommended action if the A/C system is not cooling effectively?
• What does "thermal bridging" refer to in building construction?
• What is the primary function of the compressor in an A/C system?
• Which component can cause high pressure if malfunctioning during operation?
• Who is correct regarding the effects of air and moisture in the A/C system?
• What are the benefits of regular A/C maintenance checks?
• What type of refrigerant is R-410A classified as?
• What is the correct practice for handling refrigerant oil containers?
• Which method is effective in eliminating unpleasant odors from the A/C system?
• Technician A says evacuating (pumping down) an air-conditioning system removes air and moisture from the system. Technician B says evacuating must be done anytime the system has been opened for repairs. Who is correct?
• What indicates a restriction in the A/C system based on the condition of the receiver/dryer?
• Who administers the EPA-approved certification exam on refrigerant recovery and recycling?
• What condition might cause a furnace to short cycle?
• Both low-side and high-side pressures are above normal during a performance test. What could cause this issue?
• What does "air conditioning load calculation" involve?
• What is the purpose of an air handler?
• Which statement is NOT true about orifice tube systems?
• Which of the following is NOT a cause of high side pressure above specs in an A/C system?
• Which device is commonly used to check system pressures?
• What could cause insufficient heater performance in a vehicle if one technician suspects a stuck-open thermostat and another thinks trapped air is the issue?
• What component regulates the flow of refrigerant in an A/C system?
• Where is a subcooler typically located?
• Who is correct regarding the refrigerant oil in an A/C system?
• Which technician is correct regarding the functions of hybrid vehicles having an electric water pump and a hot coolant storage tank?
• How does a heat pump differ from a conventional heater?
• If both low-side and high-side pressures are below normal, what could be a potential issue?
• What is the purpose of ductwork in a heating and cooling system?
• Which of the following is a critical safety procedure when servicing A/C units?
• Which type of heating system uses a network of ducts to distribute warm air?
• EPA certification is required to _____.
• Before recovering refrigerant, what must the technician do?
• What could be a sign of low refrigerant levels in an A/C system?
• Variable displacement compressors typically utilize which type of compressor technology?
• What is air balancing in HVAC?
• At what temperature do all materials or substances still contain heat?
• When diagnosing poor A/C performance, if only hot air is blowing out of the A/C outlets after moving the temperature control knob, who is correct?
• In a situation where heating system issues arise, which technician's statement is accurate regarding the cooling system?
• During an R-12 to R-134a conversion, what is the recommendation concerning the original receiver/dryer?
• In reference to the magnetic clutch, who is correct?
• What happens if an A/C system has excessive moisture present?
• Which technician correctly states the certification requirements for R-12 air-conditioning?
• True or False: Water vaporizes into steam at 212 degrees Fahrenheit.
• What does a restriction in the condenser indicate according to the technicians?
• When identifying refrigerants, which method is safest?
• Technician A says the presence of oil around a fitting of an air-conditioning line may indicate an oil leak but not a refrigerant leak. Technician B says using an electronic leak detector is the best way to find the source of a refrigerant leak. Who is correct?
• Why is the alignment of the compressor important in an A/C system?
• What is the primary purpose of an air conditioning system?
• Regarding environmental impact, which refrigerant is known to damage the ozone layer?
• What component is primarily responsible for compressing the refrigerant in an A/C system?
• What is the consequence of not flushing a new part after removing its seals?
• What is a common indicator of a blocked drain line in A/C systems?
• What does the owner of a car experience after the engine is shut down with the A/C running?
• What is the typical lifespan of an A/C system?
• Technician A says pinhole leaks in the evaporator may be caused by acid formed when water and refrigerant are mixed. Technician B says leaks are most often found at hose connections and at the various fittings and joints in the system. Who is correct?
• The manifold gauge set has an inches-of-mercury [vacuum] scale on which gauge?
• When diagnosing an A/C system, what is the first step a technician should take?
• What do low pressure gauge readings of 5 psi and high pressure of 105 psi at 85°F indicate?
• What does SEER stand for in air conditioning efficiency ratings?
• What is the purpose of the expansion valve in an air conditioning system?
• What does large amounts of black dust around the clutch plate indicate?
• Which refrigerant is specifically designed to align with environmentally friendly standards in A/C systems?
• What is the role of the receiver/dryer in the air conditioning system?
• What is one advantage of using programmable thermostats in heating and cooling systems?
• What is a common sign of refrigerant leaks?
• What is the ideal indoor humidity level for comfort in air conditioning?
• What does the term "zoning" refer to in HVAC systems?
• Technician A says the cabin air filter should be replaced every 12,000 to 15,000 miles. Technician B states that some filters have a charcoal layer for odor absorption. Who is correct?
• What may indicate a problem if frost is accumulating on certain lines or components?
• Which safety feature protects an air conditioning unit from overheating?
• What is NOT recommended when converting an R-12 system to R-134a?
• What HVAC component helps regulate system pressure?
• Who is correct about the effects of pressure changes on liquids?
• How does the thermal expansion valve (TEV) regulate refrigerant flow to the evaporator?
• Is the expansion valve considered a part of the receiver/dryer?
• Which refrigerant was commonly used prior to the phase-out of CFCs?
• Which statement regarding R-12 is correct?
• What distinguishes the fittings of an R-12 container from an R-134a manifold gauge set?
• What component is responsible for disengaging the compressor clutch at high pressure?
• When installing an A/C system filter without an orifice, it should be installed in which line?
• What should be done to prevent ice formation on the evaporator coil?
• What system component location is critical to monitor during A/C performance testing?
• What could be the cause if a compressor clutch will not engage despite 14.2V and a good ground at the clutch coil connector?
• What can cause ice buildup on an A/C unit?
• What does the term 'vacuum pump' refer to in the context of A/C service?
• What is the primary safety concern when working with refrigerants?
• What is the purpose of a cabin air filter in an A/C system?
• How can insulation affect heating and cooling efficiency?
• What is a recommended practice when installing conversion fittings?
• Which statement about the thermal expansion valve's function is correct?
• What is the function of the desiccant within the A/C system?
• What effect does low refrigerant have on an A/C system's performance?
• What should be the touch temperature of the suction line connected to the compressor?
• If the A/C system has been opened for more than two minutes, what should be done?
• What is a potential consequence of a clogged evaporator case drain?
• How does a condenser unit function in an A/C system?
• What is the first step in troubleshooting an A/C that is not cooling?
• Which is a characteristic of CO2 refrigerants?
• What do HVAC professionals typically use to measure air flow in ducts?
• What is commonly used to indicate when the compressor should cycle on and off?
• Technician A says a bad clutch coil could cause the A/C clutch not to engage, while Technician B says a bad clutch coil ground could be the cause. Who is correct?
• Heater control valves are operated by which of the following mechanisms?
• R-12 and R-134a _____.
• What is the primary purpose of a receiver-drier in an A/C system?
• What is a common symptom of a malfunctioning blower motor?
• Which of the following statements is NOT correct about the components of an air conditioning system?
• How are manifold gauge service hoses typically colored?
• Which technician correctly states the function of the thermostatic expansion valve and fixed orifice tube?
• How is refrigerant reclaimed during the servicing of an A/C system?
• Why is it important to maintain the correct refrigerant levels in an A/C system?
• Which is a common symptom of a failing compressor?
• What component of the air conditioning system is primarily responsible for transferring heat to the outside air?
• Which component is commonly found in both air conditioning and refrigeration systems?
• What are the signs of a failing thermostat?
• Which technician is correct regarding the A/C system in hybrid vehicles?
• A loud squealing noise could be caused by which of the following?
• In discussing a poor heat condition, which technician is correct?
• What is the main difference between a split A/C system and a window unit?
• Regarding CO2 as a refrigerant, which statement is correct?
• What high-side pressure causes the high pressure cutout switch to disengage the compressor clutch?
• In air-conditioning system safety, what is crucial when working with A/C systems?
• If a vehicle's heating system is blowing cold air, which of the following could be a potential cause?
• Which of the following statements about evaporators is NOT true?
• When diagnosing an A/C system, what does a fluctuating high-side pressure indicate?
• If the blower motor only operates in the number 4 position, what component could be failing?
• Which of the following statements is NOT correct concerning the evaporator?
• What is a potential cause for a slipping A/C belt?
• Who is correct regarding the locations of the receiver/dryer and accumulator?
• What can happen if air filters are not regularly replaced?
• Why is airflow important in heating and cooling systems?
• Which refrigerant is commonly used as a replacement for R-12?
• In HVAC systems, what does the term "SEER" stand for?
• Which of the following is a key safety standard for refrigerant storage?
• What does BTU stand for in the context of heating and cooling?
• Who is correct if Technician A uses a DMM to test the resistor block for opens while Technician B tests it with a lab scope?
• What issue can be caused by a restricted heater return hose?
• The leak-test dye in the A/C system shines what color when illuminated by a specific light?
• When evacuating an A/C system, how long should the vacuum pump remain on after reaching a certain mercury level?
• What is an advantage of using ductless mini-split systems?
• Who is correct about storing recycled refrigerant?
• What is the function of a heat exchanger in heating systems?
• Which statement is true about the normal operating pressures of refrigerants?
• What type of maintenance can help extend the life of an A/C system?
• Which part of the air conditioning system typically removes humidity from the air?
• Which statement best defines the term "evacuation" in an A/C system?
• What does the acronym HSPF stand for?
• In a CCOT system, who is correct about the associated components?
• When using electronic leak detectors, who is correct in their method of checking for leaks?
• A heating system includes all of the following parts except:
• How does an expansion valve function in an A/C unit?
• In air-conditioning systems, which of the following components is primarily responsible for refrigerant flow control?
• An R-12 to R-134a conversion procedure requires that Technician A says to leak-test the system and conduct a performance test prior to removing the R-12. Technician B says to leak-test the system and conduct a performance test after charging the system with R-134a. Who is correct?
• On systems using R-12, a sight glass is typically found with which component?
• What should a technician do upon identifying an unknown refrigerant prior to recovery?
• Who is correct about the potential causes of a poor heat condition?
• When is a manifold gauge set used?
• What do bubbles in the sight glass indicate?
• What is the purpose of a heat exchanger in heating systems?
• Which of the following statements is NOT correct regarding refrigerants?
• What is the primary purpose of the receiver/dryer in an A/C system?
• Who correctly states the refrigerant oil usage in hybrid compressors?
• What is the effect of oversized A/C units on indoor comfort?
• Which technician is correct about the compressor's functionality?
• Who is correct about the compressor oil level and system charging procedures?
• Why is refrigerant charge critical in an A/C system?
• Which of the following components may be electrically connected in series with the compressor electromagnetic clutch?
• What component is essential for removing moisture from the air in an A/C system?
• Before 1994, most manufacturers used which refrigerant?
• On which of the following laws of nature is the air-conditioning system based?
• What year did American manufacturers plan to switch to R-22?
• What is the largest and coolest line in the A/C system referred to as?
• What type of system uses chilled water to control indoor temperature?
• What is the ideal state of refrigerant prior to recovery?
• What should be done with any replaced refrigerant oil during system maintenance?
• Normally, an A/C system is charged on which side with the engine running?
• What is the main function of a capacitor in HVAC systems?
• What is the primary function of a heater core in a vehicle's heating system?
• Which technician correctly stated about A/C systems regarding R-134a by 2011?
• Where is the evaporator typically located in an A/C system?