Hydronics: Exam 2

Question 1

The water in a hydronic heating system should have a PH between

1. 1-4
2. 2-5
3. 7-10
4. 10-12

Answer 1

7 - 10

Question 2

When a circulating pump stops operating, ____ control valves prevent water from _______

Answer 2

flow, migrating

Question 3

Which of the following systems is designed so all of the circulating water passes through each component in the system?

1. series loop hydronic system
2. one-pipe hydronic
3. two-pipe hydronic

Answer 3

series loop hydronic

Question 4

Conventional boilers typically operate at water temperatures above

Answer 4

140F

Question 5

In which of the following systems does the terminal unit farthest from the boiler have the longest length of supply piping, but the shortest length of return piping?

1. direct return system
2. one-pipe system
3. series loop
4. reverse return hydronic system

Answer 5

reverse return hydronic system

Question 6

If a hydronic system is providing uneven heating, a technician should check;

1. air blockage
2. pump operation
3. zone valve operation
4. all of the above

Answer 6

all of the above

Question 7

Which of the following statements about oil-fired boilers is false?

1. a pilot light ignites the atomized fuel spray
2. the fuel oil is pumped into the burner nozzle
3. the combustion chamber is lined with refractory material

Answer 7

1. a pilot light ignites the atomized fuel spray

Question 8

A tridicator is used on an oil fired boiler to indicate water _______ and _______

Answer 8

pressure and temperature

Question 9

Which of the following statements about low-water cutoffs is false?

1. They may be float-operated
2. They may operate a makeup water valve to add more water to a system
3. They may operate a flow switch to cutoff water circulation

Answer 9

3.

Question 10

Water returning to a boiler should be at least ___ lower in temperature than water leaving the boiler.

Answer 10

20F

Question 11

T or F

glycol intended for automobile cooling systems may be used in some newer hydronic systems

Answer 11

false

Question 12

T or F

Water at a lower pressure can hold more dissolved oxygen than water at a higher pressure

Answer 12

false

Question 13

T or F

If a zone has its own circulating pump, the one valve may close a switch that starts the pump to circulate heated water through the zone

Answer 13

true

Question 14

T or F

Radiant heating systems use copper water tubing

Answer 14

false

Question 15

T or F

In a one-pipe steam heating system, the thermostatic radiator valve should be installed on the supply side of the radiator

Answer 15

false

Question 16

T or F

Excessive air bubbles in a hydronic heating system may be verified by using the systems petcocks

Answer 16

true

Question 17

T or F

Air vents may be installed on top of air separators to vent the air separated by those devices

Answer 17

true

Question 18

T or F

A four pipe hydronic system shares piping so that both the heating and cooling systems cannot function simultaneously

Answer 18

true

Question 19

T or F

Some combination heating and cooling systems are designed to operate simultaneously, allowing some spaces to be warmed and others to be cooled at the same time

Answer 19

true

Question 20

The type of air that consists of small air bubbles that travel along with circulating water is called ________ air

Answer 20

entrained air

Question 21

Valves installed in a hydronic system to ensure that water flows in the proper direction through the system are called _____ control valves

Answer 21

flow control valves

Question 22

An ________ measures the temperature of the boiler water

Answer 22

aqua stat

Question 23

If an expansion tank is hot from top to bottom, the tank is ______ logged

Answer 23

water logged

Question 24

A boiler that heats water only when heat is called for is an

Answer 24

instantaneous boiler

Question 25

A boiler in which the area under the combustion chamber is dry is a

Answer 25

dry-base boiler

Question 26

Boiler that is over 90% efficient is a

Answer 26

condensing boiler

Question 27

Boiler that operates at water temperatures above 140F is a

Answer 27

conventional boiler

Question 28

Boiler that uses finned copper tubes as heat exchangers is a

Answer 28

copper boiler

Question 29

A valve installed in the makeup water line to control pressure

Answer 29

Pressure-reducing valve

Question 30

Valve that adjusts water flow to each terminal unit so that heat is evenly distributed

Answer 30

balancing valve

Question 31

Valve installed in the makeup water line to prevent water from flowing into the water main

Answer 31

back flow preventer

Question 32

Valve that prevents water from migrating when the circulating pump quits operating

Answer 32

flow-control valve

Question 33

Valve that blends hot water from one inlet with cooler water from another inlet

Answer 33

mixing valve

Question 34

Why do room temperatures remain steady for longer periods of time with hydronic systems than with forced-air systems?

Answer 34

hydronic systems continue to radiate residual heat from water lines

Question 35

Name a way to reduce corrosion in hydronic system?

Answer 35

neutralize acidic water with alkaline

Question 36

What are corrosion inhibitors?

Answer 36

protective coating on surface of metal

Question 37

When should hydronic systems be purged?

Answer 37

if it contains large amounts of draft air