Unit 66 Review questions

Air-conditioning components are being discussed. Technician A says that a restriction device can be a fixed orifice or a thermal expansion valve. Technician B says that the purpose of the compressor is to circulate refrigerant and, with the help of a restriction, create a pressure difference. Who is correct?

• Technician A

• Technician B

• Both Technician A and Technician B

• Neither Technician A nor Technician B

Which certification is a technician required to hold before legally handling refrigerant in a vehicle?

• 609

• R-22

• ASE A7

• MVAC

Air-conditioning principles are being discussed. Technician A says that heat always travels from hot to cold. Technician B says that convection is heat that travels through solids. Who is correct?

• Technician A

• Technician B

• Both Technician A and Technician B

• Neither Technician A nor Technician B

In the heating, ventilation, and air-conditioning (HVAC) system, which component heats the surrounding air for passenger comfort when the system is set to a warm temperature?

• The thermostat

• The radiator

• The heater core

• The evaporator

The states of refrigerant are being discussed. Technician A says that when a refrigerant changes from a gas to a liquid, it absorbs heat. Technician B says that when a refrigerant changes from a liquid to a gas, it gives off heat. Who is correct?

• Technician A

• Technician B

• Both are correct

• Neither is correct

Principles of air-conditioning (A/C) are being discussed. Technician A says that if refrigerant is pressurized to about 15 to 25 psi (103.4–172.4 kPa), it will boil at about 32° F (0° C). Technician B says that as refrigerant boils in the A/C system, it gives off heat to air surrounding it. Who is correct?

• Technician A

• Technician B

• Both Technician A and Technician B

• Neither Technician A nor Technician B

A heating, ventilation, and air-conditioning (HVAC) system is being discussed. Technician A says that water dripping from under the vehicle on a humid day with the air-conditioning on may be normal. Technician B says that some manufacturers are using charcoal cabin filters, which trap odors and airborne pollutants before they enter the cabin. Who is correct?

• Technician A

• Technician B

• Both Technician A and Technician B

• Neither Technician A nor Technician B

In refrigeration, how can we force refrigerant to evaporate?

• By compressing it

• By speeding it up

• By slowing it down

• By reducing its pressure

How does air-conditioning absorb a large amount of heat energy?

• By evaporating a liquid

• By freezing a gas

• By cooling a liquid

• By cooling a gas

A heating, ventilation, and air-conditioning (HVAC) system is being discussed. Technician A says that on most vehicles, the max cold setting will pull air from the outside air to provide maximum cooling. Technician B says that on some vehicles, a heater control valve blocks coolant from entering the heater core when the temperature is set to cool. Who is correct?

• Technician A

• Technician B

• Both Technician A and Technician B

• Neither Technician A nor Technician B