Question 1

HVAC system

Accepted Answer

The acronym for Heating, Ventilation, and Air Conditioning system used in vehicles.

Question 2

Evaporator

Accepted Answer

The component in the HVAC system that cools and dehumidifies the air by absorbing heat.

Question 3

Condenser

Accepted Answer

The component in the HVAC system that releases heat to the outside air.

Question 4

Receiver-drier

Accepted Answer

A device that removes moisture and filters debris from the refrigerant in the system.

Question 5

Expansion valve

Accepted Answer

A valve that regulates the flow of refrigerant into the evaporator.

Question 6

Compressor

Accepted Answer

The component that pressurizes the refrigerant and circulates it through the system.

Question 7

Suction line

Accepted Answer

The refrigerant line that carries low-pressure vapor from the evaporator to the compressor.

Question 8

Discharge line

Accepted Answer

The refrigerant line that carries high-pressure vapor from the compressor to the condenser.

Question 9

High-side pressure

Accepted Answer

The pressure of the refrigerant on the high-pressure side of the system.

Question 10

Low-side pressure

Accepted Answer

The pressure of the refrigerant on the low-pressure side of the system.

Question 11

Superheat

Accepted Answer

The temperature of the refrigerant vapor above its boiling point.

Question 12

Subcooling

Accepted Answer

The temperature of the refrigerant liquid below its condensing point.

Question 13

Refrigerant

Accepted Answer

The substance used in the HVAC system to transfer heat between the indoor and outdoor units.

Question 14

Blend air system

Accepted Answer

A type of HVAC system that mixes outside air with recirculated air to control temperature.

Question 15

Thermostat

Accepted Answer

A device that senses and controls the temperature in the vehicle cabin.

Question 16

Pressure relief valve

Accepted Answer

A safety device that releases excess pressure in the HVAC system.

Question 17

Cabin filter

Accepted Answer

A filter that removes dust, pollen, and other particles from the air entering the cabin.

Question 18

HVAC control module

Accepted Answer

The electronic module that controls and monitors the HVAC system.

Question 19

Mode selection

Accepted Answer

The process of selecting the airflow direction (e.g., defrost, floor, face).

Question 20

Temperature control

Accepted Answer

The adjustment of the desired temperature in the vehicle cabin.

Question 21

Blower motor

Accepted Answer

The motor that powers the fan to move air through the HVAC system.

Question 22

Electrical circuits

Accepted Answer

The system of wires and components that deliver electrical power to the HVAC system.

Question 23

High-pressure switch

Accepted Answer

A safety switch that shuts off the compressor when the pressure is too high.

Question 24

Low-pressure switch

Accepted Answer

A safety switch that shuts off the compressor when the pressure is too low.

Question 25

Refrigerant recovery

Accepted Answer

The process of removing refrigerant from the system for recycling or disposal.

Question 26

Leak detection

Accepted Answer

The process of locating and repairing refrigerant leaks in the HVAC system.

Question 27

System evacuation

Accepted Answer

The process of removing air and moisture from the HVAC system.

Question 28

Retrofitting

Accepted Answer

The process of modifying the HVAC system to use a different type of refrigerant.

Question 29

Troubleshooting

Accepted Answer

The process of diagnosing and repairing problems in the HVAC system.

Question 30

PAG oil

Accepted Answer

The type of oil used in some HVAC systems as a lubricant for the compressor.

Question 31

R-134a

Accepted Answer

The most common type of refrigerant used in modern vehicle HVAC systems.

Question 32

R-1234yf

Accepted Answer

A newer, more environmentally friendly refrigerant used in some vehicle HVAC systems.

Question 33

HVAC system capacity

Accepted Answer

The ability of the HVAC system to cool or heat the vehicle cabin.

Question 34

Evaporator coil

Accepted Answer

The coil through which refrigerant flows to cool the air in the HVAC system.

Question 35

Condenser coil

Accepted Answer

The coil through which refrigerant flows to release heat in the HVAC system.

Question 36

Blower resistor

Accepted Answer

A component that controls the speed of the blower motor in the HVAC system.

Question 37

Pressure gauge

Accepted Answer

A tool used to measure the pressure of the refrigerant in the HVAC system.

Question 38

Ambient temperature sensor

Accepted Answer

A sensor that detects the temperature of the surrounding environment.

Question 39

High-pressure relief valve

Accepted Answer

A safety valve that opens to relieve excessive pressure in the system.

Question 40

Accumulator

Accepted Answer

A device that stores excess liquid refrigerant and prevents it from reaching the compressor.

Question 41

HVAC system flush

Accepted Answer

The process of cleaning out the HVAC system to remove contaminants or debris.

Question 42

Cabin pressure control

Accepted Answer

The system that regulates the pressure inside the vehicle cabin to ensure comfort and safety.

ASE School Bus Certification Test S7 Flashcards: Air Conditioning Systems & Controls