,Solution manual for Modern Hydronic Heating For
Residential and Light Commercial Buildings, 4th
Edition John Siegenthaler
Notes
1- The file is chapter after chapter.
2- We have shown you 10 or five pages.
3- The file contains all Appendix and Excel
sheet if it exists.
4- We have all what you need, we make
update at every time. There are many
new editions waiting you.
5- If you think you purchased the wrong file
You can contact us at every time, we can
replace it with true one.
Our email:
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
Solution and Answer Guide
Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and
Cooling 2023, ISBN: 9781337904919; Chapter 1: Fundamental Concepts
TABLE OF CONTENTS
End of Section Exercise Solutions ............................................................................................... 2
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 1
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
END OF SECTION EXERCISE SOLUTIONS
1. Why does ducting in forced-air heating systems have to be so much larger
than the tubing in a hydronic heating system of equal heating capacity?
Solution
Due to higher heat capacity compared to air, the volume of water that must be
moved through a building to deliver a certain amount of heat is only about
0.03% that of air. Since flow rate of water to deliver the same amount of heat
is lower, the distribution system size can be reduced.
2. Why is it better to surround a person with warm surfaces as opposed to just
warm air?
Solution
People’s bodies lose thermal energy via radiant heat transfer from their skin
surfaces to nearby colder surfaces. For this reason, most people will not be
comfortable in a room containing several cool surfaces such as large windows
or cold floors, even if the room’s temperature is 70 F.
3. What type of heat transfer creates the wind chill effect we experience during
winter?
Solution
Forced Convection
4. A certain block of material conducts heat at a rate of 100 Btu/h. One side is
maintained at 80 F and the other at 70 F. Describe what happens to the rate
of heat transfer when the:
a. The 80 F side is raised to 130 F
b. The thickness of the block is doubled
c. The 80 F side is raised to 130 F, and the thickness is cut in half
Solution
a. Assuming that the opposite side of the block is maintained at a
temperature of 70 F, the rate of heat transfer would increase.
b. If the material thickness is increased (doubling in this case), then the rate
of heat transfer would decrease.
c. Assuming that the opposite side of the block is maintained at 70 F, the
rate of heat transfer would increase.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 2
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
5. At approximately what temperature does a surface that is cooling from a high
temperature stop emitting visible radiation?
Solution
As the surface of a material cools below about 970 F, the frequency of light
the surface emits is no longer in the visible spectrum and, therefore not
detectable by our eyes.
6. How does thermal radiation differ from visible light? In what ways are they
similar?
Solution
Thermal radiation and visible light are both forms of electromagnetic energy.
Thermal radiation and visible light differ only in their wavelengths, with the
wavelength of thermal radiation being larger than that of visible light.
7. Describe thermal equilibrium within a hydronic system.
Solution
When a hydronic system is in thermal equilibrium, the rates of heat input to
and heat release from the working fluid are equal, and the working fluid
temperatures at all locations in the system are stable (no change with time).
8. What is the function of a feed water valve in a hydronic system?
Solution
The feed water value is used to reduce pressure and maintain a constant
minimum pressure in the system.
9. What is the difference between an open-loop system and a closed-loop
system?
Solution
In a closed-loop system, the circuit is sealed off from the atmosphere at all
locations. An open-loop system is open to the atmosphere at one or more
points.
10. Are there any closed-loop hydronic heating systems on which a pressure-relief
valve is not required? Why?
Solution
No, all closed-loop hydronic systems must be protected by a pressure-relief
valve.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 3
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
11. List two types of hydronic heat emitters other than finned-tube baseboard
convectors.
Solution
Fan-Coil or Air Handlers Radiant Panel
12. What is the function of a flow-check valve in a single-loop system?
Solution
In a single-loop system, the purpose of the flow-check valve is to prevent hot
water in the boiler from slowly circulating through the distribution system
when the circulator is off.
13. What is a “brine”? In what type of hydronic heating application would it be
used?
Solution
The term “brine” is a generic word for a solution of water and antifreeze such
as propylene glycol, ethylene glycol, or calcium chloride. It would be used in
special applications such as hydronic snowmelting where a pure water working
fluid could freeze.
14. Why is it necessary to have a backflow preventer in the make-up water line?
Solution
The backflow preventer stops any water that has entered the system from
returning and possibly contaminating the potable water supply system.
15. What are the customary units for heat and heat transfer rate in North
America?
Solution
The unit for heat (thermal energy) is the British thermal unit (Btu). The unit for
heat transfer rate is British thermal units per hour (Btu).
16. What is a “zoned” hydronic system?
Solution
A heating system that allows different sections of a building to be maintained
at different temperatures and thus can be adapted to the comfort needs of
several individuals.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 4
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
17. What made water flow through early hydronic systems before circulators were
used?
Solution
Early hydronic systems relied on the buoyancy of hot water to circulate water
between the boiler and the heat emitters. Because of its lower density, hot
water would rise upward from a boiler through supply pipes into heat emitters.
After releasing heat, the now slightly heavier water flowed downward back to
the boiler.
18. What causes air bubbles to form within an air separator?
Solution
The separator creates regions of reduced pressure as the water passes
through. The lowered pressure causes the dissolved gasses in the water to
form into bubbles.
19. How are the expansion tanks used in modern hydronic systems different from
those used in older systems?
Solution
Most modern hydronic systems use diaphragm-type expansion tanks. Such
tanks contain their captive air in a sealed chamber. Older hydronic systems
often used expansion tanks without diaphragms. Tanks lacking diaphragms had
to be mounted higher than the heat source and were considerably larger than
modern, diaphragm-type tanks.
20. What are some common ways small amounts of water leak out of a closed-
loop hydronic system?
Solution
Most closed-loop hydronic systems experience minor water loss over time due
to evaporation from valve packing, pump seals, air vents, and other
components.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 5
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 2: Space Heating and Domestic Water Heating Loads
Solution and Answer Guide
Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and
Cooling 2023, ISBN: 9781337904919; Chapter 2: Space Heating and Domestic
Water Heating Loads
TABLE OF CONTENTS
End of Section Exercise Solutions ............................................................................................... 2
© 2023 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible 1
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 2: Space Heating and Domestic Water Heating Loads
END OF SECTION EXERCISE SOLUTIONS
1. One wall of a room measures 14 feet long and 8 feet high. It contains a window
5 feet wide and 3.5 feet high. The wall has an effective total R-value of 15.5.
Find the rate of heat flow through the wall when the inside air temperature is
68 °F and the outside temperature is 5 °F?
Solution
It is helpful for students to sketch the elevation view of the windowed wall as
well as the wall cross-section with indoor and outdoor temperatures noted.
Gross exterior wall area = (14 ft) (8 ft) = 112 sq. ft
Window area = (5 ft) (3.5 ft) = 17.5 sq. ft
Net exterior wall area = Gross exterior wall area – Window area = 112 sq. ft. –
17.5 sq. ft. = 94.5 sq. ft.
Use Equation 2.1 (page 22) to relate heat transfer rate to the net exterior wall
area, wall thermal conductivity, wall thickness, and inside-to-outside
temperature difference:
kwall
Qwall = Anet −wall ΔT
twall
where,
Qwall = rate of heat transfer (flow) through the wall (Btu / h )
kwall = thermal conductivity of the wall (Btu / ℉ ⋅ h ⋅ ft )
© 2023 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible 2
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 2: Space Heating and Domestic Water Heating Loads
Anet-wall = net exterior area of the wall in square feet
twall = wall thickness in feet
ΔT = indoor-to-outdoor temperature difference in °F
Use Equation 2.2 to relate wall thermal conductivity and thickness to the given
R-value:
thickness t
R _ value = = , where t = thickness and k = thermal
thermal conductivity k
conductivity.
( )
Our given R-value has units of ℉ ⋅ h ⋅ ft 2 / Btu , so we can express the heat
flow rate through the net exterior portion of the wall as:
94.5ft 2 Btu
Qwall =
℉ ⋅ h ⋅ ft
2
63℉ = 384
h
( )
15.5
Btu
The total rate of heat transfer through the wall is the sum of the heat transfer
rate through the window plus the 384 Btu / h calculated for the net exterior
wall. The heat transfer rate through the window could be calculated if the R-
value of the window were known.
2. Using the data in Appendix B, determine the total effective R-value of the wall
shown in Figure 2-36. Assume that 15% of the wall area is wood framing.
Solution
The R-value of the wall assembly is the sum of the R-values of the cross-
section components, each of which can be found in Appendix B. Many of the
R-values listed in Appendix B are standardized for one-inch thicknesses, so R-
© 2023 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible 3
website, in whole or in part.
Residential and Light Commercial Buildings, 4th
Edition John Siegenthaler
Notes
1- The file is chapter after chapter.
2- We have shown you 10 or five pages.
3- The file contains all Appendix and Excel
sheet if it exists.
4- We have all what you need, we make
update at every time. There are many
new editions waiting you.
5- If you think you purchased the wrong file
You can contact us at every time, we can
replace it with true one.
Our email:
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
Solution and Answer Guide
Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and
Cooling 2023, ISBN: 9781337904919; Chapter 1: Fundamental Concepts
TABLE OF CONTENTS
End of Section Exercise Solutions ............................................................................................... 2
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 1
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
END OF SECTION EXERCISE SOLUTIONS
1. Why does ducting in forced-air heating systems have to be so much larger
than the tubing in a hydronic heating system of equal heating capacity?
Solution
Due to higher heat capacity compared to air, the volume of water that must be
moved through a building to deliver a certain amount of heat is only about
0.03% that of air. Since flow rate of water to deliver the same amount of heat
is lower, the distribution system size can be reduced.
2. Why is it better to surround a person with warm surfaces as opposed to just
warm air?
Solution
People’s bodies lose thermal energy via radiant heat transfer from their skin
surfaces to nearby colder surfaces. For this reason, most people will not be
comfortable in a room containing several cool surfaces such as large windows
or cold floors, even if the room’s temperature is 70 F.
3. What type of heat transfer creates the wind chill effect we experience during
winter?
Solution
Forced Convection
4. A certain block of material conducts heat at a rate of 100 Btu/h. One side is
maintained at 80 F and the other at 70 F. Describe what happens to the rate
of heat transfer when the:
a. The 80 F side is raised to 130 F
b. The thickness of the block is doubled
c. The 80 F side is raised to 130 F, and the thickness is cut in half
Solution
a. Assuming that the opposite side of the block is maintained at a
temperature of 70 F, the rate of heat transfer would increase.
b. If the material thickness is increased (doubling in this case), then the rate
of heat transfer would decrease.
c. Assuming that the opposite side of the block is maintained at 70 F, the
rate of heat transfer would increase.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 2
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
5. At approximately what temperature does a surface that is cooling from a high
temperature stop emitting visible radiation?
Solution
As the surface of a material cools below about 970 F, the frequency of light
the surface emits is no longer in the visible spectrum and, therefore not
detectable by our eyes.
6. How does thermal radiation differ from visible light? In what ways are they
similar?
Solution
Thermal radiation and visible light are both forms of electromagnetic energy.
Thermal radiation and visible light differ only in their wavelengths, with the
wavelength of thermal radiation being larger than that of visible light.
7. Describe thermal equilibrium within a hydronic system.
Solution
When a hydronic system is in thermal equilibrium, the rates of heat input to
and heat release from the working fluid are equal, and the working fluid
temperatures at all locations in the system are stable (no change with time).
8. What is the function of a feed water valve in a hydronic system?
Solution
The feed water value is used to reduce pressure and maintain a constant
minimum pressure in the system.
9. What is the difference between an open-loop system and a closed-loop
system?
Solution
In a closed-loop system, the circuit is sealed off from the atmosphere at all
locations. An open-loop system is open to the atmosphere at one or more
points.
10. Are there any closed-loop hydronic heating systems on which a pressure-relief
valve is not required? Why?
Solution
No, all closed-loop hydronic systems must be protected by a pressure-relief
valve.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 3
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
11. List two types of hydronic heat emitters other than finned-tube baseboard
convectors.
Solution
Fan-Coil or Air Handlers Radiant Panel
12. What is the function of a flow-check valve in a single-loop system?
Solution
In a single-loop system, the purpose of the flow-check valve is to prevent hot
water in the boiler from slowly circulating through the distribution system
when the circulator is off.
13. What is a “brine”? In what type of hydronic heating application would it be
used?
Solution
The term “brine” is a generic word for a solution of water and antifreeze such
as propylene glycol, ethylene glycol, or calcium chloride. It would be used in
special applications such as hydronic snowmelting where a pure water working
fluid could freeze.
14. Why is it necessary to have a backflow preventer in the make-up water line?
Solution
The backflow preventer stops any water that has entered the system from
returning and possibly contaminating the potable water supply system.
15. What are the customary units for heat and heat transfer rate in North
America?
Solution
The unit for heat (thermal energy) is the British thermal unit (Btu). The unit for
heat transfer rate is British thermal units per hour (Btu).
16. What is a “zoned” hydronic system?
Solution
A heating system that allows different sections of a building to be maintained
at different temperatures and thus can be adapted to the comfort needs of
several individuals.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 4
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 1: Fundemental Concepts
17. What made water flow through early hydronic systems before circulators were
used?
Solution
Early hydronic systems relied on the buoyancy of hot water to circulate water
between the boiler and the heat emitters. Because of its lower density, hot
water would rise upward from a boiler through supply pipes into heat emitters.
After releasing heat, the now slightly heavier water flowed downward back to
the boiler.
18. What causes air bubbles to form within an air separator?
Solution
The separator creates regions of reduced pressure as the water passes
through. The lowered pressure causes the dissolved gasses in the water to
form into bubbles.
19. How are the expansion tanks used in modern hydronic systems different from
those used in older systems?
Solution
Most modern hydronic systems use diaphragm-type expansion tanks. Such
tanks contain their captive air in a sealed chamber. Older hydronic systems
often used expansion tanks without diaphragms. Tanks lacking diaphragms had
to be mounted higher than the heat source and were considerably larger than
modern, diaphragm-type tanks.
20. What are some common ways small amounts of water leak out of a closed-
loop hydronic system?
Solution
Most closed-loop hydronic systems experience minor water loss over time due
to evaporation from valve packing, pump seals, air vents, and other
components.
© 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible 5
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 2: Space Heating and Domestic Water Heating Loads
Solution and Answer Guide
Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and
Cooling 2023, ISBN: 9781337904919; Chapter 2: Space Heating and Domestic
Water Heating Loads
TABLE OF CONTENTS
End of Section Exercise Solutions ............................................................................................... 2
© 2023 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible 1
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 2: Space Heating and Domestic Water Heating Loads
END OF SECTION EXERCISE SOLUTIONS
1. One wall of a room measures 14 feet long and 8 feet high. It contains a window
5 feet wide and 3.5 feet high. The wall has an effective total R-value of 15.5.
Find the rate of heat flow through the wall when the inside air temperature is
68 °F and the outside temperature is 5 °F?
Solution
It is helpful for students to sketch the elevation view of the windowed wall as
well as the wall cross-section with indoor and outdoor temperatures noted.
Gross exterior wall area = (14 ft) (8 ft) = 112 sq. ft
Window area = (5 ft) (3.5 ft) = 17.5 sq. ft
Net exterior wall area = Gross exterior wall area – Window area = 112 sq. ft. –
17.5 sq. ft. = 94.5 sq. ft.
Use Equation 2.1 (page 22) to relate heat transfer rate to the net exterior wall
area, wall thermal conductivity, wall thickness, and inside-to-outside
temperature difference:
kwall
Qwall = Anet −wall ΔT
twall
where,
Qwall = rate of heat transfer (flow) through the wall (Btu / h )
kwall = thermal conductivity of the wall (Btu / ℉ ⋅ h ⋅ ft )
© 2023 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible 2
website, in whole or in part.
, Solution and Answer Guide: John Siegenthaler, Modern Hydronic Heating and Cooling 2023, ISBN: 9781337904919;
Chapter 2: Space Heating and Domestic Water Heating Loads
Anet-wall = net exterior area of the wall in square feet
twall = wall thickness in feet
ΔT = indoor-to-outdoor temperature difference in °F
Use Equation 2.2 to relate wall thermal conductivity and thickness to the given
R-value:
thickness t
R _ value = = , where t = thickness and k = thermal
thermal conductivity k
conductivity.
( )
Our given R-value has units of ℉ ⋅ h ⋅ ft 2 / Btu , so we can express the heat
flow rate through the net exterior portion of the wall as:
94.5ft 2 Btu
Qwall =
℉ ⋅ h ⋅ ft
2
63℉ = 384
h
( )
15.5
Btu
The total rate of heat transfer through the wall is the sum of the heat transfer
rate through the window plus the 384 Btu / h calculated for the net exterior
wall. The heat transfer rate through the window could be calculated if the R-
value of the window were known.
2. Using the data in Appendix B, determine the total effective R-value of the wall
shown in Figure 2-36. Assume that 15% of the wall area is wood framing.
Solution
The R-value of the wall assembly is the sum of the R-values of the cross-
section components, each of which can be found in Appendix B. Many of the
R-values listed in Appendix B are standardized for one-inch thicknesses, so R-
© 2023 Cengage. All Rights Reserved. May not be scanned, copied, or duplicated, or posted to a publicly accessible 3
website, in whole or in part.
