Unit 22 - Chapter 98 Flashcards

0
Q

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

A

A pressure well above atmospheric pressure

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1
Q

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

A

77’C

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2
Q

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

A
  • loop system
  • one pipe system
  • two pipe direct return system
  • two pipe reverse return system
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3
Q

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

A

Diverter

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4
Q

In a radiant heating system the maximum surface temperature is

A

30’C

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5
Q

In radiant heating system changes are

A

Difficult to make

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6
Q

Automatic snow melting systems can use

A
  • hot water and antifreeze mixed
  • electric resistance heating
  • infrared lamps mounted above sidewalks and ramps
  • hot water and ethylene glycol mixed
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7
Q

Snow melting systems are usually filled with

A

Ethylene glycol and water

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8
Q

Advantages of forced circulation hot water heating systems are

A

Reduction in pipe size and greater heat storage capacity

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9
Q

A hot water boiler of the same output is

A

Smaller than a steam boiler

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10
Q

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

A

Be greater in the water system

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11
Q

Which use a boiler in the system?

A
  • steam heating
  • steam to hot water system
  • hot water heating
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12
Q

Diverted fittings are used in the supply lines to heating units

A

When a higher heating output is required from the heating unit

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13
Q

An air separator should be installed in

A

A horizontal pipe

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14
Q

The air removed by the air separator is vented to the

A

Expansion tank

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15
Q

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

A

Balancing valve is used

16
Q

The temperature control on a steam to hot water converter controls

A

The steam control valve

17
Q

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

18
Q

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

A

Maintenance costs are usually higher in a hot water system

19
Q

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

20
Q

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

A

Lower maintenance costs

21
Q

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

A

Forced circulation system

22
Q

The disadvantage of a series loop hot water heating system is

A

The individual convectors cannot be shut off

23
Q

The two pipe reverse return system has the advantage of

A

All circuits have the same length

24
Which is not a hydronic heating system?
A wet return system
25
Because of the different circuit lengths to each convector, the direct return hot water system is difficult to
Balance
26
In a radiant heating system the maximum surface temperature of the walls is
38'C
27
The working pressure and temperature of most residential and commercial applications are
85 - 140 kPa | 70 - 94'C
28
Series loop systems
Are the cheapest piping system possible
29
One pipe systems use ___ to ensure adequate flow thorough each convector
Special diverted/Venturi tee fittings
30
In the two pipe direct system
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.
31
In two pipe reverse return systems
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.
32
The temperature of water in coils of radiant panel heating systems should not be higher than
80'C for ceilings and 60'C for floors
33
In radiant panel heating, the surface temperature should not exceed
46'C in ceilings, 38'C in walls, and 30'C in floors