Question 1

Low suction pressures, iced coils, short cycling, and inefficient cooling, can also result from low head pressures .

Accepted Answer

A) True 
 B)False  True

Question 2

The shell-and-tube condenser is cleaned ____.

Accepted Answer

A)  with a brush after removing the end caps 
B)  only with chemicals 
C)  with compressed air 
D)  with a vacuum cleaner 
A)  with a brush after removing the end caps 
B)  only with chemicals 
C)  with compressed air 
D)  with a vacuum cleaner A

Question 3

Describe the construction of the tube-within-a-tube condensers .

Accepted Answer

The tube-within-a-tube is manufactured by slipping one pipe inside another and sealing the ends in such a manner that the outer tube becomes one container and the inner tube becomes another container. The two pipes are then formed into a coil to save space .

Question 4

If the spring pressure of a water regulating valve is increased, the system head pressure will also increase.

Accepted Answer

A) True 
 B)False

Question 5

In a recirculating water system condenser, the leaving water temperature is normally ____________________°F lower than the condensing temperature of the refrigerant .

Accepted Answer

The answer of In a recirculating water system condenser, the...

Question 6

In a water-cooled condenser with dirty condenser tubes, the temperature difference between the refrigerant and the leaving water will be ____ when the tubes are clean.

Accepted Answer

A)  less than 
B)  greater than 
C)  the same as 
D)  slightly lower than 
A)  less than 
B)  greater than 
C)  the same as 
D)  slightly lower than

Question 7

In a water-cooled condenser, a regulating valve is used to control the ____.

Accepted Answer

A)  refrigerant flow through the pressure reducing device 
B)  refrigerant head pressure 
C)  suction pressure 
D)  water temperature 
A)  refrigerant flow through the pressure reducing device 
B)  refrigerant head pressure 
C)  suction pressure 
D)  water temperature

Question 8

The refrigerant in a condenser in a refrigeration system ____.

Accepted Answer

A)  absorbs heat 
B)  rejects heat 
C)  changes to a vapor 
D)  is under lower pressure than the evaporator 
A)  absorbs heat 
B)  rejects heat 
C)  changes to a vapor 
D)  is under lower pressure than the evaporator

Question 9

When the evaporative condenser is used in cold climates, freeze protection must be provided in winter .

Accepted Answer

A) True 
 B)False

Question 10

If an R-12 refrigeration system has its air-cooled condensing unit on a roof with an ambient air temperature of 100°F and the condenser outlet temperature (refrigerant) is 115°F, with how much subcooling is the condenser operating ?

Accepted Answer

A)  15°F 
B)  30°F 
C)  100°F 
D)  130°F 
A)  15°F 
B)  30°F 
C)  100°F 
D)  130°F

Question 11

The typical design temperature for the water entering a recirculating water system condenser is 85°F, and most systems have a ____ rise across the condenser.

Accepted Answer

A)  1°F 
B)  5°F 
C)  10°F 
D)  15°F 
A)  1°F 
B)  5°F 
C)  10°F 
D)  15°F

Question 12

In order for a flooded condenser type head pressure control system to operate, a device called a(n) ____________________ holds the extra refrigerant in warmer weather when the condenser doesn't need to be flooded .

Accepted Answer

The answer of In order for a flooded condenser type...

Question 13

A normally operating water-cooled condenser is operating with a 10°F differential between water in and water out. If scale forms on the water tubes and the entering water is 85°F, which of the following is possible ?

Accepted Answer

A)  The outlet water temperature will be lower than expected. 
B)  The system head pressure will rise. 
C)  The water regulating valve will close. 
D)  Both a and b are correct. 
A)  The outlet water temperature will be lower than expected. 
B)  The system head pressure will rise. 
C)  The water regulating valve will close. 
D)  Both a and b are correct.

Question 14

The heat in the vicinity of the ____________________ gas has a tendency to cause any minerals in the water to deposit onto the tube surface.

Accepted Answer

The answer of The heat in the vicinity of the...

Question 15

Which of the following can be used to maintain the head pressure of a system with an air-cooled condenser?

Accepted Answer

A)  Fan cycling. 
B)  Condenser flooding. 
C)  Dampers. 
D)  All of the above. 
A)  Fan cycling. 
B)  Condenser flooding. 
C)  Dampers. 
D)  All of the above.

Question 16

The water circuit in shell-and-coil and tube-within-a-tube coil condensers must be cleaned ____.

Accepted Answer

A)  by removing the end caps 
B)  with a brush 
C)  chemically 
D)  by air pressure 
A)  by removing the end caps 
B)  with a brush 
C)  chemically 
D)  by air pressure

Question 17

High head pressures from low ambients can cause insufficient refrigerant flow rates through metering devices, which in turn can starve evaporators .

Accepted Answer

A) True 
 B)False

Question 18

What can be used to maintain the head pressure of a system with a water-cooled condenser?

Accepted Answer

A)  Fan cycling. 
B)  Dampers or louvers. 
C)  Water regulating valve. 
D)  All of the above. 
A)  Fan cycling. 
B)  Dampers or louvers. 
C)  Water regulating valve. 
D)  All of the above.

Question 19

A water regulating valve helps to maintain a system's head pressure by modulating the flow of refrigerant through the condenser.

Accepted Answer

A) True 
 B)False

Question 20

Hard starting may also occur in a low ambient condition, causing low head pressures .

Accepted Answer

A) True 
 B)False

Exam 22: Condensers

Low suction pressures, iced coils, short cycling, and inefficient cooling, can also result from low head pressures .

The shell-and-tube condenser is cleaned ____.

Describe the construction of the tube-within-a-tube condensers .

If the spring pressure of a water regulating valve is increased, the system head pressure will also increase.

In a recirculating water system condenser, the leaving water temperature is normally ____________________°F lower than the condensing temperature of the refrigerant .

In a water-cooled condenser with dirty condenser tubes, the temperature difference between the refrigerant and the leaving water will be ____ when the tubes are clean.

In a water-cooled condenser, a regulating valve is used to control the ____.

The refrigerant in a condenser in a refrigeration system ____.

When the evaporative condenser is used in cold climates, freeze protection must be provided in winter .

If an R-12 refrigeration system has its air-cooled condensing unit on a roof with an ambient air temperature of 100°F and the condenser outlet temperature (refrigerant) is 115°F, with how much subcooling is the condenser operating ?

The typical design temperature for the water entering a recirculating water system condenser is 85°F, and most systems have a ____ rise across the condenser.

In order for a flooded condenser type head pressure control system to operate, a device called a(n) ____________________ holds the extra refrigerant in warmer weather when the condenser doesn't need to be flooded .

A normally operating water-cooled condenser is operating with a 10°F differential between water in and water out. If scale forms on the water tubes and the entering water is 85°F, which of the following is possible ?

The heat in the vicinity of the ____________________ gas has a tendency to cause any minerals in the water to deposit onto the tube surface.

Which of the following can be used to maintain the head pressure of a system with an air-cooled condenser?

The water circuit in shell-and-coil and tube-within-a-tube coil condensers must be cleaned ____.

High head pressures from low ambients can cause insufficient refrigerant flow rates through metering devices, which in turn can starve evaporators .

What can be used to maintain the head pressure of a system with a water-cooled condenser?

A water regulating valve helps to maintain a system's head pressure by modulating the flow of refrigerant through the condenser.

Hard starting may also occur in a low ambient condition, causing low head pressures .

Heat and Pressure

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