Chapter 4: Hot Water Heating Systems COPY

Question 1

The water temperature in a commercial application forced circulation system may be as high as _________.
A) 94ºC (201ºF)
B) 75ºC (167ºF)
C) 250ºC (482ºF)
D) 100ºC (212ºF)

Answer 1

A) 94ºC (201ºF)

Question 2

Which of the following is an advantage for a hot water heating system compared to steam heating?
A) Minimum power requirement to circulate the water, especially in a large hot water heating system
B) Lower maintenance cost with less corrosion concerns and no steam traps requirement
C) Less damage to the heating system with hot water leakage
D) Air vents are not necessary because the system is completely filled with water in operations

Answer 2

B) Lower maintenance cost with less corrosion concerns and no steam traps requirement

Question 3

The heating coils in a snow melting system should be embedded at least ________ below the concrete surface.
A) 2cm (0.8in)
B) 10cm (4in)
C) 7.5cm (3in)
D) 5cm (2in)

Answer 3

D) 5cm (2in)

Question 4

A hot water boiler of the same output is:
A) Shorter than a steam boiler
B) Smaller than a steam boiler
C) Larger than a steam boiler
D) The same size as a steam boiler
E) Taller than a steam boiler

Answer 4

B) Smaller than a steam boiler

Question 5

A hot water heating system is also known as a ________ heating system.
A) Loop
B) Radiant panel
C) Warm air
D) Circulation
E) Hydronic

Answer 5

E) Hydronic

Question 6

Snow melting systems are usually filled with:
A) Steam
B) Methanol and water
C) Warm air
D) Ethylene glycol and water
E) Water only

Answer 6

D) Ethylene glycol and water

Question 7

The maximum temperature of water in a gravity hot water heating system is limited to approximately:
A) 77ºC
B) 87ºC
C) 67ºC
D) 65ºC
E) 70ºC

Answer 7

A) 77ºC

Question 8

An air lock on a hot water heating system:
A) Will block circulation
B) Is a more difficult problem than in a steam system
C) Will cause some areas of the system to be cold
D) Requires more complex piping to prevent than in a steam system
E) All of the above

Answer 8

E) All of the above

Question 9

In a one-pipe hot water heating system the fitting that directs the water to each convector is called the:
A) Diverter
B) Lead
C) Trap
D) Vent valve
E) Separator

Answer 9

A) Diverter

Question 10

In a radiant panel heating system the maximum floor surface temperature is:
A) 30ºC
B) 50ºC
C) 10ºC
D) 40ºC
E) 20ºC

Answer 10

A) 30ºC

Question 11

In a hot water heating system compared to a steam heating system, if there is a leak the damage will:
A) Be minimal due to the automatic drain system
B) Be greater in the hot water system
C) Be about the same in either system
D) Depend on where the boiler is located in the system
E) Be greater in the steam system

Answer 11

B) Be greater in the hot water system

Question 12

In many buildings, the hot water heating system is divided into several circuits and the flow of water is controlled by a/an:
A) Thermostat
B) Thermometer
C) Thermocouple
D) Circulating pump in each heating zone
E) Expansion tank in each heating zone

Answer 12

D) Circulating pump in each heating zone

Question 13

One of the advantages of hot water heating as compared to steam heating is:
A) Water treatment is almost eliminated
B) Hot water boilers are more fuel efficient
C) Less damage in the event of a leak
D) More piping is needed
E) Lower maintenance cost

Answer 13

E) Lower maintenance cost

Question 14

In the one-pipe hot water heating system, the heating units are:
A) Connected in series so the water circulates from the hot water supply main directly through all the convectors to the return main
B) All supplied with water at the same temperature and the return from each convector flows the long way around to return to the boiler
C) Equipped with its own circulating pump
D) Supplied from the main and the return from each convector is connected back to the main again downstream from the supply connection
E) All supplied with water at the same temperature and the return from each convector flows by the shortest and most direct route

Answer 14

D) Supplied from the main and the return from each convector is connected back to the main again downstream from the supply connection

Question 15

Compared to a steam heating system, which of the following is an advantage of a hot water heating system?
A) If a leak does occur, more damage will result with a hot water system than with a steam system
B) In a multi-story building the boiler must be designed to withstand high pressure due to the high head of water in the system
C) In a large hot water system, considerable power is required to circulate the water
D) There is a greater danger of damage due to freezing in a hot water system
E) Hot water boilers are smaller and more compact

Answer 15

E) Hot water boilers are smaller and more compact

Question 16

The gravity hot water heating system had a disadvantage of:
A) Positive circulation to radiators on the same level as the boiler
B) There is a quick response to changes in heat demand
C) Large pipe sizes to keep flow resistance to a minimum
D) Simple operation and low maintenance
E) The minimum water temperature is limited to 77ºC (171ºF)

Answer 16

C) Large pipe sizes to keep flow resistance to a minimum

Question 17

A hot water heating system also known as a __________ heating system is similar in many respects to a steam heating system.
A) Hydraulic
B) Hydronic
C) Liquid
D) Latent
E) Wet

Answer 17

B) Hydronic

Question 18

An advantage of the forced circulation hot water heating system is:
A) Positive circulation can not be established to all heating units
B) Increased power and maintenance costs
C) The response to changes in heating load is more rapid
D) Larger pipes must be used
E) Noisier operation

Answer 18

C) The response to changes in heating load is more rapid

Question 19

In the two-pipe direct return hot water heating system, the heating units are:
A) All supplied with water at the same temperature and the return from each convector flows by the shortest and most direct route back to the boiler
B) Equipped with its own circulating pump
C) Supplied from the main and the return from each convector is connected back to the main again downstream from the supply connection
D) All supplied with water at the same temperature and the return from each convector flows the long way around to return to the boiler
E) Connected in series so the water circulates from the hot water supply main directly through all the convectors to the return main

Answer 19

A) All supplied with water at the same temperature and the return from each convector flows by the shortest and most direct route back to the boiler

Question 20

The water temperature in a hot water heating system may vary from:
A) 70ºC to90ºC (158ºF to 201ºF)
B) 75ºC to 110ºC (167ºF to 230ºF)
C) 50ºC to 100ºC (122ºF to 212ºF)
D) 100ºC to 150ºC (212ºF to 302ºF)
E) 250ºC to 300ºC (482ºF to 572ºF)

Answer 20

A) 70ºC to 90ºC (158ºF to 201ºF)

Question 21

The gravity hot water heating system had a disadvantage of:
A) Small pipe sizes to keep flow resistance to a minimum
B) There is a quick response to changes in heat demand
C) The maximum water temperature is limited to 77ºC (171ºF)
D) Positive circulation to radiators on the same level as the boiler
E) Simple operation and low maintenance

Answer 21

C) The maximum water temperature is limited to 77ºC (171ºF)

Question 22

Temperatures used in radiant panel heating in ceilings should not exceed:
A) 30ºC (86ºF)
B) 52ºC (126ºF)
C) 46ºC (115ºF)
D) 38ºC (100ºF)
E) 25ºC (77ºF)

Answer 22

C) 46ºC (115ºF)

Question 23

In the two-pipe reverse return hot water heating system, the heating units are:
A) Connected in series so the water circulates from the hot water supply main directly through all the convectors to the return main
B) Supplied from the main and the return from each convector is connected back to the main again downstream from the supply connection
C) Equipped with its own circulating pump
D) All supplied with water at the same temperature and the return from each convector flows the long way around to return to the boiler
E) All supplied with water at the same temperature and the return from each convector flows by the shortest and most direct route back to the boiler

Answer 23

D) All supplied with water at the same temperature and the return from each convector flows the long way around to return to the boiler