Unit 22 - Chapter 98

Question 0

In a forced circulation system the expansion tank allows the system to operate at

Answer 0

A pressure well above atmospheric pressure

Question 1

The maximum temperature of water in a gravity hot water system is

Answer 1

77’C

Question 2

A forced hot water circulating system can be classified as the following type

Answer 2

• loop system
• one pipe system
• two pipe direct return system
• two pipe reverse return system

Question 3

In a one pipe hot water system the fitting that directs the water to each converter is called the

Answer 3

Diverter

Question 4

In a radiant heating system the maximum surface temperature is

Answer 4

30’C

Question 5

In radiant heating system changes are

Answer 5

Difficult to make

Question 6

Automatic snow melting systems can use

Answer 6

• hot water and antifreeze mixed
• electric resistance heating
• infrared lamps mounted above sidewalks and ramps
• hot water and ethylene glycol mixed

Question 7

Snow melting systems are usually filled with

Answer 7

Ethylene glycol and water

Question 8

Advantages of forced circulation hot water heating systems are

Answer 8

Reduction in pipe size and greater heat storage capacity

Question 9

A hot water boiler of the same output is

Answer 9

Smaller than a steam boiler

Question 10

In a hot water system compared to a steam heating system, if there is a leak damage will

Answer 10

Be greater in the water system

Question 11

Which use a boiler in the system?

Answer 11

• steam heating
• steam to hot water system
• hot water heating

Question 12

Diverted fittings are used in the supply lines to heating units

Answer 12

When a higher heating output is required from the heating unit

Question 13

An air separator should be installed in

Answer 13

A horizontal pipe

Question 14

The air removed by the air separator is vented to the

Answer 14

Expansion tank

Question 15

To ensure that each zone circuit has the proper flow of water to provide the required heat, a

Answer 15

Balancing valve is used

Question 16

The temperature control on a steam to hot water converter controls

Answer 16

The steam control valve

Question 17

A hot water system circulates water through the pipes with which pump?

Answer 17

Forced

Question 18

Which is not an advantage of a hot water system compared to a steam heating system?

Answer 18

Maintenance costs are usually higher in a hot water system

Question 19

The maximum temperature of the water in radiant panel heating coils for ceilings is about

Answer 19

80’C

Question 20

One of the advantages of the hot water heating as compared to steam heating is

Answer 20

Lower maintenance costs

Question 21

A hot water system which circulates water through the pipes with a pump is known as a

Answer 21

Forced circulation system

Question 22

The disadvantage of a series loop hot water heating system is

Answer 22

The individual convectors cannot be shut off

Question 23

The two pipe reverse return system has the advantage of

Answer 23

All circuits have the same length

Question 24

Which is not a hydronic heating system?

Answer 24

A wet return system

Question 25

Because of the different circuit lengths to each convector, the direct return hot water system is difficult to

Answer 25

Balance

Question 26

In a radiant heating system the maximum surface temperature of the walls is

Answer 26

38’C

Question 27

The working pressure and temperature of most residential and commercial applications are

Answer 27

85 - 140 kPa

70 - 94’C

Question 28

Series loop systems

Answer 28

Are the cheapest piping system possible

Question 29

One pipe systems use ___ to ensure adequate flow thorough each convector

Answer 29

Special diverted/Venturi tee fittings

Question 30

In the two pipe direct system

Answer 30

The temperature of water entering each convector is the same for all, while all circuit lengths are different; pipe size is critical for equal flow.

Question 31

In two pipe reverse return systems

Answer 31

All circuits have the same length and all connectors receive the same amount of water at the same temperature; pipe size is not as critical.

Question 32

The temperature of water in coils of radiant panel heating systems should not be higher than

Answer 32

80’C for ceilings and 60’C for floors

Question 33

In radiant panel heating, the surface temperature should not exceed

Answer 33

46’C in ceilings, 38’C in walls, and 30’C in floors