Chapter 54: Heating and Air Conditioning Test

Thermostatic Expansion Valve

TEV or TXV stands for___________________________.

cable, electronically or vacuum operated

What can air flow control valve doors be?

The high-pressure, high-temperature liquid

What state is the refrigerant in when it leaves the condenser?

A stationary clutch coil

What type of electromagnetic clutch is used in late-model vehicles?

Heater core, the heater control value, the blower motor, the fan, and the heater and defroster ducts

What are the main components of an automotive heating system?

The process of heat loss from the air to the evaporator core surface.

What causes condensed water to leak from the air-conditioning system?

Objects can be in one of three forms: solid, liquid, or gas. When objects change from one state to another, large amounts of heat can be transferred.

What does "change of state" mean? And why is it important to air-conditioning units?

latent heat or hidden heat

What is the amount of heat necessary to change the state of a substance called?

light blue or blue

What is the color of R-134a?

It stops the compressor from running because of the temperature getting close to the freezing point.

What is the purpose of the compressor clutch thermostatic switch?

They have an auxiliary positive temperature coefficient (PTC) unit or a PTC heating element in the heater core.

What kind of unit does hybrid vehicles have?

D. PAG (Polyalkaline glycol oil)

Which of the following oils is used in an original equipment R-134a system? A. mineral oil B. CCOT C. Ester Oil D. PAG (Polyalkaline Glycol oil)

D. none of the above

Which of the following statements is true? A. Refrigerant leaves the compressor as a high-pressure, high temperature liquid. B. Refrigerant leaves the condenser as a low-pressure, low temperature liquid. C. Refrigerant returns to the compressor as a low-pressure, high- temperature vapor. D. None of the above.

D. all of the above

Which of the following statements is true? A. the condenser is normally mounted just in front of the radiator. B. The receiver/dryer is a storage tank for the liquid refrigerant from the condenser. C. An accumulator is not used in any system with a receiver/dryer. D. all of the above

Chlorofluorocarbon (CFC)

___________________ are depleting the protective ozone layer through a chemical reaction.

Receiver/dryer

A heating system includes all of the following parts except a ______________________.

Little, no heat output, form, little to no heat

A low coolant level can starve the heater, resulting in _____________ or _________________________. Air pockets can _________ and create ___________________________.

Discharge Side

An air conditioning design that controls the output of the system by cycling the compressor's clutch.

Cycling clutch

An air-conditioning design that controls the output of the system by cycling the compressor's clutch.

Polyester oil

POE stands for_________________.

A/C case, distribution plenum, evaporating housing

The case and duct systems are also called_____________________?

Condensation

The process of a vapor becoming a liquid; the reverse of evaporation.

Axial, parallel, shaft

These compressors are normally ___________________ compressors, with pistons arranged around and _________ to the drive ___________.

A wobble plate or a swash plate

What are the pistons driven by?

Heat is produced and the air that passes through the heater core is warmed

What happens when current passes through a PTC element?

212 degrees Fahrenheit

What is the boiling point of water?

D. all of the above

Which of the following is electrically connected in series with the compressor electromagnetic clutch? A. ambient temperature switch B. Thermostatic switch C. pressure cycling switch D. all of the above.

Heater control valve

A manual or automatic value in the heater hose used for opening or closing, providing coolant plow control to the heater core.

Evaporation

A natural process in which the moisture contained be an object leaves and enters the atmosphere.

Heater Core

A small heat changer in the passenger compartment through which the engine coolant is circulated.

Diagnostic Trouble Control

DTC stands for............

By cable, thermostat, vacuum, or electronically

Describe four ways in which the heater control valve may be controlled?

To absorb voltage spikes when the clutch disengages.

Explain why a diode may be wired into the compressor clutch circuit.

Heating, Ventilation, and Air Conditioning

HVAC stands for...........

An under hood decal and by the hoses and fittings used in the system.

How are all R-134a systems identified by?

Original Equipment Manufactor

OEA stands for..............

D. all of the above

On which of the following laws of nature is the air-conditioning system based? A. Heat Flow C. Pressure and Boiling Points B. Heat Absorption D. all of the above

Electronically controlled and work independently of the cooling system

PTC Heaters are ____________________.

Refrigeration System

The chemical compound used in a ________________________________to produce the desired cooling.

Hydroflurocarbon (HFC)

The chemical family currently used as the source of refrigerant for air-conditioning systems. It contains no chlorine and causes less damage to the ozone layer when released to the atmosphere.

High Side

The high pressure portion of an air-conditioning system.

Low Side

The low pressure portion of an air-conditioning system.

False

True or False? PTC Heaters are electronically controlled and work with the cooling system to provide hot coolant.

Instead of a receiver/dryer, they use an accumulator to accomplish the same thing.

What are most late-model systems equipped with?

White

What is the color of R-12?

Diode

a simple semiconductor device that permits flow of electricity in one direction, but not in the opposite direction.