Refrigeration and Basic HVAC Systems

Question 1

A _____ system is one which the evaporator coil comes into direct contact with the medium to be cooled.

Answer 1

Direct

Question 2

Skating rinks use _____ as the medium to obtain low temperatures necessary for the ice surface and prevent the secondary refrigerant from freezing.

Answer 2

Brine

Question 3

In an ammonia absorption system, the ammonia is heated into a vapor by a _____ coil located in the generator (concentrator).

Answer 3

Steam

Question 4

In an ammonia absorption system, the condenser would change the high pressure vapor into high pressure ______.

Answer 4

Liquids

Question 5

In an ammonia absorption system, the ______________ would separate the high side condenser from the low side evaporator.

Answer 5

Metering Valve

Question 6

In an ammonia absorption system, the secondary refrigerant located in the evaporator would be ________ when used in a building cooling system.

Answer 6

Chilled Water

Question 7

Refrigeration is the science of producing and maintaining temperatures below that of the surrounding ________ by transferring heat from one place to another.

Answer 7

Atmosphere

Question 8

Refrigeration engineers, particularly those associated with ________, finally decided to call all fluids used in refrigeration systems refrigerants with an identification number to cover all refrigerants.

Answer 8

ASHRAE

Question 9

The ________ components of these refrigerants have been found to contribute significantly to the depletion of the ozone layer.

Answer 9

Chlorine

Question 10

Group _____ refrigerants are considered dangerous and should only be used for industrial applications.

Answer 10

A3

Question 11

The presence of escaping refrigerant will cause the flame of a ________ torch to turn green if there is a small leak or dense blue if there is a large leak.

Answer 11

Halide

Question 12

Refrigeration R-717, more commonly known as _________, is one of the oldest refrigerants and because of its heat-absorbing ability is considered one of the best.

Answer 12

Ammonia

Question 13

Too much oil accumulation in the ______ and ________ could cause there to be a shortage of oil in the crankcase of the compressor.

Answer 13

Evaporator and condenser

Question 14

In the mid 1980s, the ______ _______ was established to ban, limit, and replace the existing CFC type refrigerants.

Answer 14

Montreal Protocol

Question 15

The new refrigerants use _________ oil.

Answer 15

Polyester

Question 16

A piston type compressor is classified as _________.

Answer 16

Reciprocating

Question 17

_________ units contain a compressor that is directly coupled to an electric motor, both of which are sealed inside a welded steel case.

Answer 17

Hermetic

Question 18

An ________ type compressor will have a shaft protruding outside of the body connected to a motor by either a pulley or a direct drive coupling.

Answer 18

Open

Question 19

The evaporators will ______ the heat from the medium being cooled.

Answer 19

Absorb

Question 20

The compressor generates the high and low side of the system; it will also create ________ ___ ___________ when the refrigerant passes through the exhaust portion of the compression cycle.

Answer 20

Heat of Compression

Question 21

The type of evaporator that is widely used in air conditioning applications where the dry or direct expansion method is used would be a ___________ coil type.

Answer 21

Finned Tube

Question 22

The shell and tube evaporator is referred to as a _______ and is used to cool a secondary refrigerant.

Answer 22

Chiller

Question 23

The three basic types of condensers are _________, ____________, and ___________.

Answer 23

Air Cooled, Water Cooled, and Evaporative

Question 24

To increase condenser capacity, air can be forced or drawn through the condenser could by means of ______ or ______.

Answer 24

Blowers or Fans

Question 25

The evaporative condenser uses both conduction and evaporation for the rejection of the heat process. To make up water due to the evaporation process, you would install a ___________ in the pan.

Answer 25

Float Valve

Question 26

To remove non-condensable gases and moisture prior to adding refrigerant to the system; the entire system would need to be _________.

Answer 26

Evacuated

Question 27

Liquid receivers are built to the ASME _________ code.

Answer 27

Section VIII

Question 28

The flow control device establishes a pressure differential between the ________ and the ________.

Answer 28

Condenser and Evaporator

Question 29

_______ type metering valves are used in conjunction with the flooded evaporator.

Answer 29

Float

Question 30

________ _________ is not suitable for air conditioning systems where the load is frequently changed since they do not respond to changes in temperature.

Answer 30

Constant pressure

Question 31

The __________ valve opens and closes in response to the downstream superheated temperatures of the evaporator.

Answer 31

Thermostatic

Question 32

The orifice or capillary tube will allow the refrigerant in the system to ________ _________ when the compressor is off.

Answer 32

Equalize pressure

Question 33

The high side of a refrigeration system would not include:

Answer 33

An intake valve on compressor

Question 34

A flooded evaporator would have a ________ metering valve.

Answer 34

High side float

Question 35

An example of an indirect refrigeration system is a:

Answer 35

Pipe coil in a curling rink

Question 36

Where a condenser is used, the best type for heat removal is an:

Answer 36

Evaporative

Question 37

The type of metering valve that is manually operated and will require continuous supervision is the:

Answer 37

Needle valve

Question 38

The thermostatic metering valve operates by sensing:

Answer 38

Superheat

Question 39

The type of valve that senses temperature change with a thermistor is a:

Answer 39

Thermal-electric valve

Question 40

A one pipe system is ideally suited for:

Answer 40

Perimeter baseboard installations

Question 41

A three pipe system will not contain:

Answer 41

A split AC system

Question 42

A chilled water coil will be:

Answer 42

Piped opposite of the steam coil.

Question 43

The three (3) most important principles of air factors used on an air conditioning system is:

Answer 43

Temperature, humidification and air motion

Question 44

Bacteria and disease can be controlled by using:

Answer 44

Filtration

Question 45

A priority of air conditioning in pulp mills is to:

Answer 45

Reduce the amount of humidity

Question 46

(T/F) Heat always flows from a lower temperature substance to a higher temperature substance.

Answer 46

False

Question 47

(T/F) A heat pump can be used for both heating and cooling, regardless of the season.

Answer 47

True

Question 48

(T/F) The water source is the most common type of energy source used for a heat pump.

Answer 48

False

Question 49

(T/F) Geothermal heat pumps can be classified as either open loop or closed loop systems.

Answer 49

True

Question 50

(T/F) There are only two heat pump cycles.

Answer 50

True

Question 51

(T/F) The variable heat pumps have moving dampers and a fixed refrigeration cycle.

Answer 51

False

Question 52

The type of filter that can be reused and regenerated using an oil based substance is:

Answer 52

Viscous impingement type

Question 53

The most common type of fan or blower used on a furnace or an RTU is the:

Answer 53

Squirrel cage fan

Question 54

The type of air conditioning equipment that requires the most service is the:

Answer 54

RTU - unitary

Question 55

Downstream of a dual-duct mechanical room, each air conditioned room or area is required to have a _________ installed.

Answer 55

Mixing box

Question 56

The type of ducting designed for high-velocity ducting is a:

Answer 56

Round duct

Question 57

An essential item required on a steam heating coil with an automatic control valve is a:

Answer 57

Vacuum breaker

Question 58

The type of coil design that is used when air temperature across a coil is greater than 35°F and 55°F is:

Answer 58

Installed two deep

Question 59

Cooling towers are interconnected to:

Answer 59

Condensers

Question 60

The most common energy source for a heat pump is:

Answer 60

Air source

Question 61

A variable heat pump system will have:

Answer 61

Two metering valves

Question 62

The fixed heat pump system will control the heat/cool cycle by the use of:

Answer 62

Motorized dampers

Question 63

Icing of the evaporator is caused by:

Answer 63

Low refrigerant pressure in the evaporator

Question 64

The receiver on a refrigeration system is located:

Answer 64

Upstream of the filter/ dryer

Question 65

The safety valve from a receiver should be piped:

Answer 65

Away from air intakes