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Flashcards in Key Points Deck (28)
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1
Q

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.

A

True

2
Q

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

A

True

3
Q

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

A

True

4
Q

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

A

True

5
Q

Refrigerants have a reletionship between temperature and pressure

A

True

6
Q

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

A

True

7
Q

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

A

True

8
Q

A compressor is a mechanical device that compresses refrigerant vapor

A

True

9
Q

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

A

True

10
Q

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

A

True

11
Q

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

A

True

12
Q

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

A

True

13
Q

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

A

True

14
Q

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

A

True

15
Q

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

A

True

16
Q

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

A

True

17
Q

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

A

True

18
Q

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

A

True

19
Q

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

A

True

20
Q

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

A

True

21
Q

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

A

True

22
Q

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

A

True

23
Q

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

A

True

24
Q

Many refrigerants have been found to damage the environent

A

True

25
Q

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

A

True

26
Q

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

A

True

27
Q

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.

A

True

28
Q

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.

A

True