Key Points

Question 1

The three states of matter are solid, liquid, and gas. Substances change state when laten heat is added or remove. Substances change temperature when sensible heat is added or remove.

Answer 1

True

Question 2

Heat always flow from a material at a higher temperature to a material at a lower remperature

Answer 2

True

Question 3

Density is the mass of a substance that fits into a specified volume.

Answer 3

True

Question 4

Specific volume is the volume that a specific weght of gas will occupy under specific conditions

Answer 4

True

Question 5

Refrigerants have a reletionship between temperature and pressure

Answer 5

True

Question 6

A ton of cooling is the amount of cooling provided by melting (2000 lb) of ice withing a 24 hr period

Answer 6

True

Question 7

A refrigerant is a chemical substance that boils at a low temperature and is used for transporting heat in a cooling system

Answer 7

True

Question 8

A compressor is a mechanical device that compresses refrigerant vapor

Answer 8

True

Question 9

A condenser is a heat exchanger that removes heat from a high-pressure refrigerant vapor

Answer 9

True

Question 10

A metering device is a component of the refrigerant system that controls the flow of refrigerant into the evaporation

Answer 10

True

Question 11

An evaporator is a heat exchanger through which heat is transferred to low-pressure liquid refrigerant

Answer 11

True

Question 12

A liquid receiver is a storage tank for the collection of liquid refrigerant

Answer 12

True

Question 13

A suction accumulator is a container located between the evaporator and the compressor that catches any liquid refrigerant before the refrigerant reaches the compressor and causes damage

Answer 13

True

Question 14

A purge unit is a device used to maintain a system free of air and moisture

Answer 14

True

Question 15

The two common types of cooling systems are direct-expansion system (direct-cooling systems) and chilled water system (indirect cooling system)

Answer 15

True

Question 16

A direct-expansion system is a cooling systemin which the evaporator is in direct contact with the air in the building space

Answer 16

True

Question 17

A chilled water system is a cooling system in which water or other liquid is chilled and circulated to the building space

Answer 17

True

Question 18

The most common direct-expansion system used for cooling are iar conditioning and heat pumps

Answer 18

True

Question 19

An air conditioner uses direc expansion of the refrigerant in the evaporator coil to cool the building interior air

Answer 19

True

Question 20

A heat pump uses direct expansion of the refrigerant in an indoor coil to heat or cool the biulding’s interior air, while an outdoor coil used to absorb or reject the heat

Answer 20

True

Question 21

An absortion chiller system is a nonmechanical refrigeration system that uses a fluid with the ability to absorb a vapor when it is cool and release a vapor when heated

Answer 21

True

Question 22

An ammonia-water absorption chiller system is an absorption chiller system that uses ammonia as the refrigerant and a solution of ammonia and water as the absorbent

Answer 22

True

Question 23

A lithium bromide-water absorpion chiller is an absorption chiller system that uses water as the refrigerant and a solution of lithium bromide and water as the absorbent

Answer 23

True

Question 24

Many refrigerants have been found to damage the environent

Answer 24

True

Question 25

The three classifications of refrigerant most technicians work with today are chlorofluorocarbons (CFCs). Hydrochlorofluorocarbon (HCFCs) and hydrofluorocarbons (HFCs).

Answer 25

True

Question 26

Service technicians must be certified in order to purchase and handle refrigerants. The four certifications are Type I, Type II, Type III, and Universal

Answer 26

True

Question 27

Technicians may not knowengly vent or otherwise release or dispose of any substance used as a refrigerant in a manner that permits such substance to enter the environment. Refrigerants must be recovered, recycled, or reclaimed.

Answer 27

True

Question 28

Refrigerants can cause frostbite to unprotected skin and freezing of the eyes, and can create environment problems in the form of ozone depletion and global warming.

Answer 28

True