Exam 54: Heating and Air Conditioning

Heater core and evaporator core temperatures can be easily measured with a ____________________.

Technician A says suction lines connect the accumulator to the compressor. Technician B says discharge lines connect the compressor to the condenser. Who is correct?

Technician A says the magnetic clutch is usually pressure controlled, cycling the compressor on and off to regulate system temperature or pressure. Technician B says the clutch operates continually when the system is turned on. Who is correct?

The use of any refrigerant that contains ____________________ substances, such as propane and butane, is illegal and dangerous.

Technician A says the thermostatic expansion valve and the fixed orifice tube perform the same function. Technician B says heat from the evaporator core surface is lost to the boiling and vaporizing refrigerant. Who is correct?

Technician A says hybrid vehicles use electrically driven high voltage A/C compressors. Technician B says the compressors for hybrids use the same refrigerant oil as regular vehicles. Who is correct?

The heater core may be plugged if the inlet hose feels hot and the outlet hose feels cool.

What is the purpose of an A/C system's electromagnet clutch?

What is the purpose of a blend door?

More than half of the heat that is in a vehicle's passenger compartment comes from solar radiation.

Technician A says European and Japanese manufacturers shipping vehicles to the US will eliminate R-134a A/C systems by 2017. Technician B says the United States will switch to R-22 in 2015. Who is correct?

Technician A says the compressor can pump both liquids and vapor. Technician B says the compressor is driven off the crankshaft by a belt. Who is correct?

In most vehicles, the air-conditioning compressor will turn off when the defroster is selected by the driver and the ambient temperature is more than 35°F.

The heater control valve is often called the water flow valve.

Heat always flows from a warmer object to a colder one.

Technician A says a CCOT system has an expansion valve and a sight glass. Technician B says a CCOT system has an accumulator. Who is correct?

What refrigerant is currently slated to replace R134a?

The ozone layer protects Earth from receiving an excessive amount of the sun's ____________________ rays.

Which of the following statements concerning R-12 is correct?

A poor heat condition is being discussed. Technician A says a disconnected engine vacuum hose could not cause the problem. Technician B says a seized blend door could cause the problem. Who is correct?