Solution Manual For Refrigeration and Air Conditioning Technology, 8th Edition
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’s Manual
to Accompany
Refrigeration
and
Air Conditioning
Technology
8th Edition
Concepts, Procedures, and
Troubleshooting Techniques
John A. Tomczyk
Eugene Silberstein
William C. Whitman
William M. Johnson
SOLUTION MANUAL
to Accompany
Refrigeration
and
Air Conditioning
Technology
8th Edition
Concepts, Procedures, and
Troubleshooting Techniques
John A. Tomczyk
Eugene Silberstein
William C. Whitman
William M. Johnson
SOLUTION MANUAL
Preface v
PART I ’s Guide 1
Unit 1 Heat, Temperature, and Pressure 1
Unit 2 Matter and Energy 3
Unit 3 Refrigeration and Refrigerants 6
Unit 4 General Safety Practices 10
Unit 5 Tools and Equipment 11
Unit 6 Fasteners 12
Unit 7 Tubing and Piping 14
Unit 8 Leak Detection, System Evacuation, and System Cleanup 17
Unit 9 Refrigerant and Oil Chemistry and Management—Recovery, Recycling,
Reclaiming, and Retrofitting 20
Unit 10 System Charging 23
Unit 11 Calibrating Instruments 26
Unit 12 Basic Electricity and Magnetism 28
Unit 13 Introduction to Automatic Controls 31
Unit 14 Automatic Control Components and Applications 33
Unit 15 Troubleshooting Basic Controls 36
Unit 16 Advanced Automatic Controls—Direct Digital Controls (DDCs)
and Pneumatics 38
Unit 17 Types of Electric Motors 40
Unit 18 Application of Motors 42
Unit 19 Motor Controls 44
Unit 20 Troubleshooting Electric Motors 46
Unit 21 Evaporators and the Refrigeration System 48
Unit 22 Condensers 50
Unit 23 Compressors 53
Unit 24 Expansion Devices 56
Unit 25 Special Refrigeration System Components 59
Unit 26 Applications of Refrigeration Systems 62
Unit 27 Commercial Ice Machines 65
Unit 28 Special Refrigeration Applications 69
Unit 29 Troubleshooting and Typical Operating Conditions for
Commercial Refrigeration 70
Unit 30 Electric Heat 72
Unit 31 Gas Heat 75
Unit 32 Oil Heat 82
Unit 33 Hydronic Heat 86
Unit 34 Indoor Air Quality 89
Unit 35 Comfort and Psychrometrics 91
Unit 36 Refrigeration Applied to Air-Conditioning 93
Unit 37 Air Distribution and Balance 95
Unit 38 Installation 98
Unit 39 Residential Energy Auditing 101
Unit 40 Typical Operating Conditions 105
Unit 41 Troubleshooting 107
Unit 42 Heat Gains and Heat Losses in Structures 110
Unit 43 Air Source Heat Pumps 112
Unit 44 Geothermal Heat Pumps 116
iii
Contents
PART I ’s Guide 1
Unit 1 Heat, Temperature, and Pressure 1
Unit 2 Matter and Energy 3
Unit 3 Refrigeration and Refrigerants 6
Unit 4 General Safety Practices 10
Unit 5 Tools and Equipment 11
Unit 6 Fasteners 12
Unit 7 Tubing and Piping 14
Unit 8 Leak Detection, System Evacuation, and System Cleanup 17
Unit 9 Refrigerant and Oil Chemistry and Management—Recovery, Recycling,
Reclaiming, and Retrofitting 20
Unit 10 System Charging 23
Unit 11 Calibrating Instruments 26
Unit 12 Basic Electricity and Magnetism 28
Unit 13 Introduction to Automatic Controls 31
Unit 14 Automatic Control Components and Applications 33
Unit 15 Troubleshooting Basic Controls 36
Unit 16 Advanced Automatic Controls—Direct Digital Controls (DDCs)
and Pneumatics 38
Unit 17 Types of Electric Motors 40
Unit 18 Application of Motors 42
Unit 19 Motor Controls 44
Unit 20 Troubleshooting Electric Motors 46
Unit 21 Evaporators and the Refrigeration System 48
Unit 22 Condensers 50
Unit 23 Compressors 53
Unit 24 Expansion Devices 56
Unit 25 Special Refrigeration System Components 59
Unit 26 Applications of Refrigeration Systems 62
Unit 27 Commercial Ice Machines 65
Unit 28 Special Refrigeration Applications 69
Unit 29 Troubleshooting and Typical Operating Conditions for
Commercial Refrigeration 70
Unit 30 Electric Heat 72
Unit 31 Gas Heat 75
Unit 32 Oil Heat 82
Unit 33 Hydronic Heat 86
Unit 34 Indoor Air Quality 89
Unit 35 Comfort and Psychrometrics 91
Unit 36 Refrigeration Applied to Air-Conditioning 93
Unit 37 Air Distribution and Balance 95
Unit 38 Installation 98
Unit 39 Residential Energy Auditing 101
Unit 40 Typical Operating Conditions 105
Unit 41 Troubleshooting 107
Unit 42 Heat Gains and Heat Losses in Structures 110
Unit 43 Air Source Heat Pumps 112
Unit 44 Geothermal Heat Pumps 116
iii
Contents
Preface v
PART I ’s Guide 1
Unit 1 Heat, Temperature, and Pressure 1
Unit 2 Matter and Energy 3
Unit 3 Refrigeration and Refrigerants 6
Unit 4 General Safety Practices 10
Unit 5 Tools and Equipment 11
Unit 6 Fasteners 12
Unit 7 Tubing and Piping 14
Unit 8 Leak Detection, System Evacuation, and System Cleanup 17
Unit 9 Refrigerant and Oil Chemistry and Management—Recovery, Recycling,
Reclaiming, and Retrofitting 20
Unit 10 System Charging 23
Unit 11 Calibrating Instruments 26
Unit 12 Basic Electricity and Magnetism 28
Unit 13 Introduction to Automatic Controls 31
Unit 14 Automatic Control Components and Applications 33
Unit 15 Troubleshooting Basic Controls 36
Unit 16 Advanced Automatic Controls—Direct Digital Controls (DDCs)
and Pneumatics 38
Unit 17 Types of Electric Motors 40
Unit 18 Application of Motors 42
Unit 19 Motor Controls 44
Unit 20 Troubleshooting Electric Motors 46
Unit 21 Evaporators and the Refrigeration System 48
Unit 22 Condensers 50
Unit 23 Compressors 53
Unit 24 Expansion Devices 56
Unit 25 Special Refrigeration System Components 59
Unit 26 Applications of Refrigeration Systems 62
Unit 27 Commercial Ice Machines 65
Unit 28 Special Refrigeration Applications 69
Unit 29 Troubleshooting and Typical Operating Conditions for
Commercial Refrigeration 70
Unit 30 Electric Heat 72
Unit 31 Gas Heat 75
Unit 32 Oil Heat 82
Unit 33 Hydronic Heat 86
Unit 34 Indoor Air Quality 89
Unit 35 Comfort and Psychrometrics 91
Unit 36 Refrigeration Applied to Air-Conditioning 93
Unit 37 Air Distribution and Balance 95
Unit 38 Installation 98
Unit 39 Residential Energy Auditing 101
Unit 40 Typical Operating Conditions 105
Unit 41 Troubleshooting 107
Unit 42 Heat Gains and Heat Losses in Structures 110
Unit 43 Air Source Heat Pumps 112
Unit 44 Geothermal Heat Pumps 116
iii
Contents
PART I ’s Guide 1
Unit 1 Heat, Temperature, and Pressure 1
Unit 2 Matter and Energy 3
Unit 3 Refrigeration and Refrigerants 6
Unit 4 General Safety Practices 10
Unit 5 Tools and Equipment 11
Unit 6 Fasteners 12
Unit 7 Tubing and Piping 14
Unit 8 Leak Detection, System Evacuation, and System Cleanup 17
Unit 9 Refrigerant and Oil Chemistry and Management—Recovery, Recycling,
Reclaiming, and Retrofitting 20
Unit 10 System Charging 23
Unit 11 Calibrating Instruments 26
Unit 12 Basic Electricity and Magnetism 28
Unit 13 Introduction to Automatic Controls 31
Unit 14 Automatic Control Components and Applications 33
Unit 15 Troubleshooting Basic Controls 36
Unit 16 Advanced Automatic Controls—Direct Digital Controls (DDCs)
and Pneumatics 38
Unit 17 Types of Electric Motors 40
Unit 18 Application of Motors 42
Unit 19 Motor Controls 44
Unit 20 Troubleshooting Electric Motors 46
Unit 21 Evaporators and the Refrigeration System 48
Unit 22 Condensers 50
Unit 23 Compressors 53
Unit 24 Expansion Devices 56
Unit 25 Special Refrigeration System Components 59
Unit 26 Applications of Refrigeration Systems 62
Unit 27 Commercial Ice Machines 65
Unit 28 Special Refrigeration Applications 69
Unit 29 Troubleshooting and Typical Operating Conditions for
Commercial Refrigeration 70
Unit 30 Electric Heat 72
Unit 31 Gas Heat 75
Unit 32 Oil Heat 82
Unit 33 Hydronic Heat 86
Unit 34 Indoor Air Quality 89
Unit 35 Comfort and Psychrometrics 91
Unit 36 Refrigeration Applied to Air-Conditioning 93
Unit 37 Air Distribution and Balance 95
Unit 38 Installation 98
Unit 39 Residential Energy Auditing 101
Unit 40 Typical Operating Conditions 105
Unit 41 Troubleshooting 107
Unit 42 Heat Gains and Heat Losses in Structures 110
Unit 43 Air Source Heat Pumps 112
Unit 44 Geothermal Heat Pumps 116
iii
Contents
iv Contents
Unit 45 Domestic Refrigerators and Freezers 118
Unit 46 Room Air Conditioners 121
Unit 47 High-pressure, Low-pressure, and Absorption Chilled-Water Systems 123
Unit 48 Cooling Towers and pumps 126
Unit 49 Operation, Maintenance, and Troubleshooting of
Chilled-Water Air-Conditioning Systems 128
Unit 50 Commercial packaged Rooftop, Variable Refrigerant Flow, and
Variable Air Volume Systems 130
PART II Lecture Outlines 133
PART III Correlation Guide 365
Unit 45 Domestic Refrigerators and Freezers 118
Unit 46 Room Air Conditioners 121
Unit 47 High-pressure, Low-pressure, and Absorption Chilled-Water Systems 123
Unit 48 Cooling Towers and pumps 126
Unit 49 Operation, Maintenance, and Troubleshooting of
Chilled-Water Air-Conditioning Systems 128
Unit 50 Commercial packaged Rooftop, Variable Refrigerant Flow, and
Variable Air Volume Systems 130
PART II Lecture Outlines 133
PART III Correlation Guide 365
Heat, Temperature, and Pressure 1
PART I ’s Guide
Heat, Temperature, and Pressure
This unit covers temperature, methods of measuring
and transferring heat, and discussions pertaining to
molecular motion, sensible heat, latent heat, and specific
heat. It also discusses atmospheric pressure and test
instruments such as gauges used to measure pressure.
There are review questions at the end of the unit in the
text that may be assigned as an out-of-class activity and
then used to enhance class discussion. Key terms listed in
the Lab Manual and Workbook may also be used as an as-
signment and/or basis for discussion. The Review Test in the
Lab Manual and Workbook may be used as an end-of-unit
test or for further discussion.
OBJECTIVES
After studying this unit, the student should be able to:
● define temperature.
● make conversions between the Fahrenheit and Celsius
scales.
● describe molecular motion at absolute zero.
● define the British thermal unit.
● describe heat flow between substances of different
temperatures.
● explain the transfer of heat by conduction, convec-
tion, and radiation.
● discuss sensible heat, latent heat, and specific heat.
● state atmospheric pressure at sea level and explain
why it varies at different elevations.
● describe two types of barometers.
● explain psig and psia as they apply to pressure
measurements.
SAFETY ChECklIST
● HVAC/R technicians are often exposed to very high
and very low temperatures. Be sure to wear gloves and
other appropriate pieces of personal protection equip-
ment (PPE) to reduce the chances of getting injured.
● Many fluids that are used by the HVAC/R technicians
are under pressure. Be sure to transport all pressure
vessels vertically and be sure they are properly secured.
● Make certain that all tanks are properly capped to
prevent accidental releases from the tanks.
● Make certain all test instruments are properly cali-
brated and fully operational to ensure accurate pres-
sure and temperature readings.
AhRI CURRICUlUM GUIDE COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
● PRINCIPLES OF THERMODYNAMICS AND HEAT
TRANSFER
Matter and Heat Behavior
Fluids and Pressures
EXERCISES (lAB MANUAl)
Exercises 1-1 and 1-2
UNIT 1 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. B.
2. At atmospheric pressure of 14.696 psia or 29.92 in Hg.
3. Fahrenheit, Celsius, Rankine, and Kelvin.
4. 0°C.
5. −460°F.
6. 1 pound of water 1°F.
7. D.
8. Heat transfers from molecule to molecule.
9. A.
10. C.
11. Heat is transferred by moving in a medium such as
air or water.
12. Heat is transferred through space without heating
the space and heats the first solid object the heat
energy strikes.
13. Substance.
14. 29.92 in Hg, 14.696 psia.
15. 14.696.
16. 26.7°C.
17. 71.6°F.
Unit 1
1
PART I ’s Guide
Heat, Temperature, and Pressure
This unit covers temperature, methods of measuring
and transferring heat, and discussions pertaining to
molecular motion, sensible heat, latent heat, and specific
heat. It also discusses atmospheric pressure and test
instruments such as gauges used to measure pressure.
There are review questions at the end of the unit in the
text that may be assigned as an out-of-class activity and
then used to enhance class discussion. Key terms listed in
the Lab Manual and Workbook may also be used as an as-
signment and/or basis for discussion. The Review Test in the
Lab Manual and Workbook may be used as an end-of-unit
test or for further discussion.
OBJECTIVES
After studying this unit, the student should be able to:
● define temperature.
● make conversions between the Fahrenheit and Celsius
scales.
● describe molecular motion at absolute zero.
● define the British thermal unit.
● describe heat flow between substances of different
temperatures.
● explain the transfer of heat by conduction, convec-
tion, and radiation.
● discuss sensible heat, latent heat, and specific heat.
● state atmospheric pressure at sea level and explain
why it varies at different elevations.
● describe two types of barometers.
● explain psig and psia as they apply to pressure
measurements.
SAFETY ChECklIST
● HVAC/R technicians are often exposed to very high
and very low temperatures. Be sure to wear gloves and
other appropriate pieces of personal protection equip-
ment (PPE) to reduce the chances of getting injured.
● Many fluids that are used by the HVAC/R technicians
are under pressure. Be sure to transport all pressure
vessels vertically and be sure they are properly secured.
● Make certain that all tanks are properly capped to
prevent accidental releases from the tanks.
● Make certain all test instruments are properly cali-
brated and fully operational to ensure accurate pres-
sure and temperature readings.
AhRI CURRICUlUM GUIDE COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
● PRINCIPLES OF THERMODYNAMICS AND HEAT
TRANSFER
Matter and Heat Behavior
Fluids and Pressures
EXERCISES (lAB MANUAl)
Exercises 1-1 and 1-2
UNIT 1 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. B.
2. At atmospheric pressure of 14.696 psia or 29.92 in Hg.
3. Fahrenheit, Celsius, Rankine, and Kelvin.
4. 0°C.
5. −460°F.
6. 1 pound of water 1°F.
7. D.
8. Heat transfers from molecule to molecule.
9. A.
10. C.
11. Heat is transferred by moving in a medium such as
air or water.
12. Heat is transferred through space without heating
the space and heats the first solid object the heat
energy strikes.
13. Substance.
14. 29.92 in Hg, 14.696 psia.
15. 14.696.
16. 26.7°C.
17. 71.6°F.
Unit 1
1
2 Unit 1
Fahrenheit Celsius Rankine Kelvin
(−460) (−273) 0 (0)
32 (0) (492) (273)
(212) 100 (672) (373)
(140) (60) 600 (333)
(−460) (−273) (0) 0
200 (93) (660) (366)
(−360) (−218) 100 (55)
(122) 50 (582) (323)
(81) (27) (541) 300
(32) 0 (492) (273)
150 (66) (610) (339)
(−410) (−246) 50 (27)
(−40) −40 (420) (233)
−40 (−40) (420) (233)
212 (100) (672) (373)
(212) (100) (672) 373
(−460) −273 (0) (0)
(212) (100) 672 (373)
5 (−15) (465) (258)
(441) (227) (901) 500
COMPlETED TEMPERATURE CONVERSION ChART FROM EXERCISE 1-1
(Bolded values in parentheses represent the items that were to be filled in by the student.)
ANSWERS TO QUESTIONS IN
EXERCISE 1-1
ANSWERS TO QUESTIONS IN
EXERCISE 1-2
1. D.
2. C.
3. A.
4. A.
5. A.
6. C.
1. A.
2. C.
3. A.
4. A.
5. A.
6. C.
UNIT 1 ANSWERS TO REVIEW TEST QUESTIONS (lAB MANUAl)
1. C.
2. A.
3. A.
4. A.
5. C.
6. B.
7. A.
8. A.
9. D.
10. D.
11. C.
12. B.
13. D.
14. A.
15. C.
16. D.
17. A.
18. B.
19. B.
20. B.
Fahrenheit Celsius Rankine Kelvin
(−460) (−273) 0 (0)
32 (0) (492) (273)
(212) 100 (672) (373)
(140) (60) 600 (333)
(−460) (−273) (0) 0
200 (93) (660) (366)
(−360) (−218) 100 (55)
(122) 50 (582) (323)
(81) (27) (541) 300
(32) 0 (492) (273)
150 (66) (610) (339)
(−410) (−246) 50 (27)
(−40) −40 (420) (233)
−40 (−40) (420) (233)
212 (100) (672) (373)
(212) (100) (672) 373
(−460) −273 (0) (0)
(212) (100) 672 (373)
5 (−15) (465) (258)
(441) (227) (901) 500
COMPlETED TEMPERATURE CONVERSION ChART FROM EXERCISE 1-1
(Bolded values in parentheses represent the items that were to be filled in by the student.)
ANSWERS TO QUESTIONS IN
EXERCISE 1-1
ANSWERS TO QUESTIONS IN
EXERCISE 1-2
1. D.
2. C.
3. A.
4. A.
5. A.
6. C.
1. A.
2. C.
3. A.
4. A.
5. A.
6. C.
UNIT 1 ANSWERS TO REVIEW TEST QUESTIONS (lAB MANUAl)
1. C.
2. A.
3. A.
4. A.
5. C.
6. B.
7. A.
8. A.
9. D.
10. D.
11. C.
12. B.
13. D.
14. A.
15. C.
16. D.
17. A.
18. B.
19. B.
20. B.
Loading page 6...
3
Matter and Energy
Unit 2
This unit defines matter, mass, density, specific grav-
ity, and specific volume. Gas laws, including Boyle’s
law, Charles’ law, the general law of perfect gas, and
Dalton’s law, are stated. The broad subject of energy
is covered, as well as energy in heat and in magnetism.
The measurement of energy in horsepower, watts, and
British thermal units is discussed. Unit review questions,
key terms in the Lab Manual and Workbook, and Lab
Manual and Workbook Review Test questions may be
used, as discussed in Unit 1.
OBJECTIVES
After studying this unit, the student should be able to:
●● define matter.
●● list the three states in which matter is commonly found.
●● define density.
●● discuss Boyle’s law.
●● state Charles’ law.
●● discuss Dalton’s law as it relates to the pressure of
different gases.
●● define specific gravity and specific volume.
●● state two forms of energy important to the HVAC/R
industry.
●● describe work and state the formula used to determine
the amount of work done by performing a given task.
●● define horsepower.
●● convert horsepower to watts.
●● convert watt-hours to British thermal units.
SAFETY ChECklIST
●● Power-consuming devices have the potential to cause
injury. Be sure to de-energize all pumps, motors and
other electrical devices before working on them.
●● When measuring pressures, be sure that your test
instruments are fully operational and properly cali-
brated to avoid possible injury.
EXERCISES (lAB MANUAl)
Exercises 2-1, 2-2, and 2-3
UNIT 2 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. D.
2. Solid, liquid, and gas.
3. Ice.
4. Down.
5. Downward and outward.
6. D.
7. Weight per unit volume of a substance.
8. The density of a substance compared to the density
of water.
9. The volume occupied by 1 pound of a fluid.
10. The moon has less mass than the earth, thus its
gravitational pull is weaker.
11. Specific volume 5 1 1210 lb/ft3 5 0.000826 ft3
/lb.
12. Density 5 1 (0.001865 ft3
/lb) 5 536.19 lb/ft3
.
13. Specific gravity 5 171 lb/ft3 62.4 lb/ft3 5 2.74.
14. Density is (4 lb 10 ft3
) 5 0.4 lb/ft3
.
Specific gravity is (0.4 lb/ft 3 62.4 lb/ft 3
) 5 0.0064.
15. It describes how one gas reacts when mixed with
another. For example, natural gas is lighter than
air and rises; propane is heavier than air and falls.
Specific volume must be considered when determin-
ing the size of compressors or vapor pumps. Specific
volume of air also provides the HVAC/R system
designer with information regarding how many
pounds of air are being moved by blowers and fans.
16. B.
17. It will expand when heated or contract when cooled.
18. Dalton’s law states that the total pressure of a con-
fined mixture of gases is the sum of the pressures of
each of the gases in the mixture.
19. Solar and fossil fuels.
20. From decaying animal and vegetable matter com-
pressed below the earth’s surface.
21. Power.
22. Force 3 distance.
23. 4 ft 3 300 lb 5 1200 foot-pounds.
24. An early expression of power, or the equivalent of
raising 33,000 pounds to a height of 1 foot in one
minute. Weight, height, and time.
25. 746 watts 5 1 horsepower.
26. (4 kW 3 3413 Btu/kW) 5 13,652 Btu/h.
27. 12,000 watts 3 3.413 Btu/Wh 5 40,956 Btu/h.
28. Kilowatt hour.
Matter and Energy
Unit 2
This unit defines matter, mass, density, specific grav-
ity, and specific volume. Gas laws, including Boyle’s
law, Charles’ law, the general law of perfect gas, and
Dalton’s law, are stated. The broad subject of energy
is covered, as well as energy in heat and in magnetism.
The measurement of energy in horsepower, watts, and
British thermal units is discussed. Unit review questions,
key terms in the Lab Manual and Workbook, and Lab
Manual and Workbook Review Test questions may be
used, as discussed in Unit 1.
OBJECTIVES
After studying this unit, the student should be able to:
●● define matter.
●● list the three states in which matter is commonly found.
●● define density.
●● discuss Boyle’s law.
●● state Charles’ law.
●● discuss Dalton’s law as it relates to the pressure of
different gases.
●● define specific gravity and specific volume.
●● state two forms of energy important to the HVAC/R
industry.
●● describe work and state the formula used to determine
the amount of work done by performing a given task.
●● define horsepower.
●● convert horsepower to watts.
●● convert watt-hours to British thermal units.
SAFETY ChECklIST
●● Power-consuming devices have the potential to cause
injury. Be sure to de-energize all pumps, motors and
other electrical devices before working on them.
●● When measuring pressures, be sure that your test
instruments are fully operational and properly cali-
brated to avoid possible injury.
EXERCISES (lAB MANUAl)
Exercises 2-1, 2-2, and 2-3
UNIT 2 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. D.
2. Solid, liquid, and gas.
3. Ice.
4. Down.
5. Downward and outward.
6. D.
7. Weight per unit volume of a substance.
8. The density of a substance compared to the density
of water.
9. The volume occupied by 1 pound of a fluid.
10. The moon has less mass than the earth, thus its
gravitational pull is weaker.
11. Specific volume 5 1 1210 lb/ft3 5 0.000826 ft3
/lb.
12. Density 5 1 (0.001865 ft3
/lb) 5 536.19 lb/ft3
.
13. Specific gravity 5 171 lb/ft3 62.4 lb/ft3 5 2.74.
14. Density is (4 lb 10 ft3
) 5 0.4 lb/ft3
.
Specific gravity is (0.4 lb/ft 3 62.4 lb/ft 3
) 5 0.0064.
15. It describes how one gas reacts when mixed with
another. For example, natural gas is lighter than
air and rises; propane is heavier than air and falls.
Specific volume must be considered when determin-
ing the size of compressors or vapor pumps. Specific
volume of air also provides the HVAC/R system
designer with information regarding how many
pounds of air are being moved by blowers and fans.
16. B.
17. It will expand when heated or contract when cooled.
18. Dalton’s law states that the total pressure of a con-
fined mixture of gases is the sum of the pressures of
each of the gases in the mixture.
19. Solar and fossil fuels.
20. From decaying animal and vegetable matter com-
pressed below the earth’s surface.
21. Power.
22. Force 3 distance.
23. 4 ft 3 300 lb 5 1200 foot-pounds.
24. An early expression of power, or the equivalent of
raising 33,000 pounds to a height of 1 foot in one
minute. Weight, height, and time.
25. 746 watts 5 1 horsepower.
26. (4 kW 3 3413 Btu/kW) 5 13,652 Btu/h.
27. 12,000 watts 3 3.413 Btu/Wh 5 40,956 Btu/h.
28. Kilowatt hour.
Loading page 7...
4 Unit 2
29. The pressure is constant so V
T
V
T
1
1
2
2
.
V V T
T2
1 2
1
V2
3000 55 460 2887 8
( )( ) .
ft R
(75 460) R ft
3
3°
°
30. PV
T
P V
T
1 1
1
2 2
2
P PV T
T V2
1 1 2
1 2
P2
10 180 460
( )( )psig 14.696) (10.5 in R
(65 46
3 ° °
00) R(1.5 in 3
° )
P2 5 210.74 psia
P2 5 (210.74 psia 2 14.696) 5 196 psig
ANSWERS TO QUESTIONS IN
EXERCISE 2-1
1. D. 2. C. 3. A. 4. A.
Line P1 V1 T1 P2 V2 T2
1 50 psig 20 ft 3 100°F (25 psia) 50 ft3 80°F
2 50 psia 2,000 ft3 75°F 50 psia (2291 ft3) 130°F
3 40 psia 30 in3 80°F 50 psia (24 ft3) 80°F
4 (100 psia) 20 ft3 500 R 200 psia 12 ft3 600 R
5 100 psia 10 ft3 600 R 100 psia 25 ft3 (1500 R)
6 80 psia (150 ft3) 400 R 150 psia 100 ft3 500 R
7 150 psia 100 ft3 (700 R) 300 psia 50 ft3 700 R
8 80 psia 500 ft3 600 R (160 psia) 100 ft3 240 R
COMPlETED ChART FROM EXERCISE 2-2
(Bolded values in parentheses represent the items that
were to be filled in by the student.)
Substance
Density
(lb/in3
)
Density
(oz/in3 )
Density
(lb/ft3
)
Specific
Gravity Substance
A (0.7) (11.2) 1208 (19.36) (GOLD)
B (0.036) (0.58) (62.4) 1 (WATER)
C (0.317) (5.07) (548) (8.78) RED BRASS
D 0.3218 (5.15) (556) (8.91) (COPPER)
E (0.033) 0.5324 (57.5) (0.92) (ICE)
F (0.099) (1.58) 171 (2.74) (ALUMINUM)
G (0.70) (11.2) (1210) 19.39 (TUNGSTEN)
H (0.094) (1.5) (162) (2.596) MARBLE
1. C.
2. A.
3. B.
4. C.
5. D.
6. A.
7. D.
8. C.
9. C.
10. D.
11. D.
12. D.
13. C.
COMPlETED ChART FROM EXERCISE 2-1
(Bolded values in parentheses represent the items that
were to be filled in by the student.)
UNIT 2 ANSWERS TO REVIEW TEST
QUESTIONS (lAB MANUAl)
29. The pressure is constant so V
T
V
T
1
1
2
2
.
V V T
T2
1 2
1
V2
3000 55 460 2887 8
( )( ) .
ft R
(75 460) R ft
3
3°
°
30. PV
T
P V
T
1 1
1
2 2
2
P PV T
T V2
1 1 2
1 2
P2
10 180 460
( )( )psig 14.696) (10.5 in R
(65 46
3 ° °
00) R(1.5 in 3
° )
P2 5 210.74 psia
P2 5 (210.74 psia 2 14.696) 5 196 psig
ANSWERS TO QUESTIONS IN
EXERCISE 2-1
1. D. 2. C. 3. A. 4. A.
Line P1 V1 T1 P2 V2 T2
1 50 psig 20 ft 3 100°F (25 psia) 50 ft3 80°F
2 50 psia 2,000 ft3 75°F 50 psia (2291 ft3) 130°F
3 40 psia 30 in3 80°F 50 psia (24 ft3) 80°F
4 (100 psia) 20 ft3 500 R 200 psia 12 ft3 600 R
5 100 psia 10 ft3 600 R 100 psia 25 ft3 (1500 R)
6 80 psia (150 ft3) 400 R 150 psia 100 ft3 500 R
7 150 psia 100 ft3 (700 R) 300 psia 50 ft3 700 R
8 80 psia 500 ft3 600 R (160 psia) 100 ft3 240 R
COMPlETED ChART FROM EXERCISE 2-2
(Bolded values in parentheses represent the items that
were to be filled in by the student.)
Substance
Density
(lb/in3
)
Density
(oz/in3 )
Density
(lb/ft3
)
Specific
Gravity Substance
A (0.7) (11.2) 1208 (19.36) (GOLD)
B (0.036) (0.58) (62.4) 1 (WATER)
C (0.317) (5.07) (548) (8.78) RED BRASS
D 0.3218 (5.15) (556) (8.91) (COPPER)
E (0.033) 0.5324 (57.5) (0.92) (ICE)
F (0.099) (1.58) 171 (2.74) (ALUMINUM)
G (0.70) (11.2) (1210) 19.39 (TUNGSTEN)
H (0.094) (1.5) (162) (2.596) MARBLE
1. C.
2. A.
3. B.
4. C.
5. D.
6. A.
7. D.
8. C.
9. C.
10. D.
11. D.
12. D.
13. C.
COMPlETED ChART FROM EXERCISE 2-1
(Bolded values in parentheses represent the items that
were to be filled in by the student.)
UNIT 2 ANSWERS TO REVIEW TEST
QUESTIONS (lAB MANUAl)
Loading page 8...
Matter and Energy 5
ANSWERS TO QUESTIONS IN
EXERCISE 2-2
1. D.
2. B.
3. Absolute pressure and temperature scales both have
zero as their lowest values, so any pressure above
0 psia or temperature above zero degrees Rankin will
be indicated by positive values. By keeping all of the
values positive, the gas law as shown in Section 2.6
of the textbook will be a linear relationship existing
among the pressure, temperature, and volume of the
gas. If non-absolute scales are used, the relationships
become non-linear and significant calculation errors
can, and will, arise.
COMPlETED ChART FROM EXERCISE 2-3
(Bolded values in parentheses represent the items that
were to be filled in by the student.)
Line
Distance
(ft)
Weight
(lb)
Work
(ft-lb)
Time
(min)
Power
(W)
Power
(kW)
Heat
(btuh) HP
1 500 100 (50,000) 5 (226) (0.226) (771) 0.303
2 (20) 500 10,000 2 113.03 (0.113) (386) (0.15)
3 (4,409) 250 (1,102,200) 1 (24,905) (24.91) 85,000 (33.4)
4 1000 (1,106) (1,105,500) 2 (25,000) 25 (85,325) (33.5)
5 (1000) 150 150,000 (0.06) (55,950) (55.95) (190,957) 75
6 10,000 (22.12) (221,180) 10 (5,000) 5 (17,065) (6.7)
7 (518.4) 500 (259,220) 1 (5,860) (5.86) 20,000 (7.86)
8 5,000 (518.4) (2,592,200) 5 (58,600) (58.6) 200,000 (78.6)
ANSWERS TO QUESTIONS IN
EXERCISE 2-3
1. B.
2. D.
3. B.
ANSWERS TO QUESTIONS IN
EXERCISE 2-2
1. D.
2. B.
3. Absolute pressure and temperature scales both have
zero as their lowest values, so any pressure above
0 psia or temperature above zero degrees Rankin will
be indicated by positive values. By keeping all of the
values positive, the gas law as shown in Section 2.6
of the textbook will be a linear relationship existing
among the pressure, temperature, and volume of the
gas. If non-absolute scales are used, the relationships
become non-linear and significant calculation errors
can, and will, arise.
COMPlETED ChART FROM EXERCISE 2-3
(Bolded values in parentheses represent the items that
were to be filled in by the student.)
Line
Distance
(ft)
Weight
(lb)
Work
(ft-lb)
Time
(min)
Power
(W)
Power
(kW)
Heat
(btuh) HP
1 500 100 (50,000) 5 (226) (0.226) (771) 0.303
2 (20) 500 10,000 2 113.03 (0.113) (386) (0.15)
3 (4,409) 250 (1,102,200) 1 (24,905) (24.91) 85,000 (33.4)
4 1000 (1,106) (1,105,500) 2 (25,000) 25 (85,325) (33.5)
5 (1000) 150 150,000 (0.06) (55,950) (55.95) (190,957) 75
6 10,000 (22.12) (221,180) 10 (5,000) 5 (17,065) (6.7)
7 (518.4) 500 (259,220) 1 (5,860) (5.86) 20,000 (7.86)
8 5,000 (518.4) (2,592,200) 5 (58,600) (58.6) 200,000 (78.6)
ANSWERS TO QUESTIONS IN
EXERCISE 2-3
1. B.
2. D.
3. B.
Loading page 9...
6
Refrigeration and Refrigerants
Unit 3
This unit includes a history of refrigeration and a basic
discussion of the refrigeration process. Using water and
refrigerants as examples, the temperature/pressure rela-
tionship is discussed and is followed by a description of
the four major refrigeration components: the evaporator,
compressor, condenser, and metering device. The unit
also includes a more detailed description of the refrig-
eration cycle and a brief description of the reciprocating,
rotary, scroll, centrifugal, and screw compressors. Newer,
more popular long-term refrigerants and refrigerant
replacements are covered along with refrigerants with
phase-out dates in the near future. Refrigerant leak de-
tection, recovery and recycling, cylinder color codes, and
chemical makeup are discussed. This unit also covers the
issue of the ozone layer depletion attributed to haloge-
nated chlorofluorocarbons. Several pages are devoted to
plotting systems on pressure/enthalpy diagrams.
OBJECTIVES
After studying this unit, the student should be able to:
• discuss applications for high-, medium-, and low-
temperature refrigeration.
• describe the term ton of refrigeration.
• describe the basic refrigeration cycle.
• explain the relationship between pressure and the
boiling point of water or other liquids.
• describe the function of the evaporator or cooling coil.
• explain the purpose of the compressor.
• list the compressors normally used in residential and
light commercial buildings.
• discuss the function of the condensing coil.
• state the purpose of the metering device.
• list four characteristics to consider when choosing a
refrigerant for a system.
• list the designated colors for refrigerant cylinders for
various types of refrigerants.
• describe how refrigerants can be stored or processed
while refrigeration systems are being serviced.
• plot a refrigeration cycle for refrigerants (R-22,
R-134a, and R-502) on a pressure/enthalpy diagram.
• plot a refrigeration cycle on a pressure/enthalpy dia-
gram for refrigerant blends R-404A and R-410A.
• plot a refrigeration cycle on a pressure/enthalpy
diagram for refrigerant blend (R-407C) that has a
noticeable temperature glide.
SAFETY ChECklIST
• Areas in which there could be potential refrigerant
leaks should be ventilated.
• Extra precautions should be taken to ensure that no
refrigerant leaks occur near an open flame.
• Refrigerants are stored in pressurized containers and
should be handled with care. Goggles with side shields
and gloves should be worn when checking pressures and
when transferring refrigerants from the container to a
system or from the system to an approved container.
AhRI CURRICUlUM GUIDE
COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
• INTRODUCTION
Introduction to Refrigeration
• PRINCIPLES OF THERMODYNAMICS AND
HEAT TRANSFER
Matter and Heat Behavior
Fluids and Pressures
Refrigeration Cycle/Diagrams
• REFRIGERANT RECOVERY
Refrigerant Recovery, Recycling, and Reclamation
Methods
Refrigerant Recovery, Recycling, and Reclamation
Equipment
• REFRIGERANTS AND LUBRICANTS
Refrigerants
• REGULATIONS
Regulations Affecting Ozone Depletion
EXERCISES (lAB MANUAl)
Exercises 3-1, 3-2, and 3-3
UNIT 3 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. Warm food, air leakage when door is opened, con-
duction through the walls.
Refrigeration and Refrigerants
Unit 3
This unit includes a history of refrigeration and a basic
discussion of the refrigeration process. Using water and
refrigerants as examples, the temperature/pressure rela-
tionship is discussed and is followed by a description of
the four major refrigeration components: the evaporator,
compressor, condenser, and metering device. The unit
also includes a more detailed description of the refrig-
eration cycle and a brief description of the reciprocating,
rotary, scroll, centrifugal, and screw compressors. Newer,
more popular long-term refrigerants and refrigerant
replacements are covered along with refrigerants with
phase-out dates in the near future. Refrigerant leak de-
tection, recovery and recycling, cylinder color codes, and
chemical makeup are discussed. This unit also covers the
issue of the ozone layer depletion attributed to haloge-
nated chlorofluorocarbons. Several pages are devoted to
plotting systems on pressure/enthalpy diagrams.
OBJECTIVES
After studying this unit, the student should be able to:
• discuss applications for high-, medium-, and low-
temperature refrigeration.
• describe the term ton of refrigeration.
• describe the basic refrigeration cycle.
• explain the relationship between pressure and the
boiling point of water or other liquids.
• describe the function of the evaporator or cooling coil.
• explain the purpose of the compressor.
• list the compressors normally used in residential and
light commercial buildings.
• discuss the function of the condensing coil.
• state the purpose of the metering device.
• list four characteristics to consider when choosing a
refrigerant for a system.
• list the designated colors for refrigerant cylinders for
various types of refrigerants.
• describe how refrigerants can be stored or processed
while refrigeration systems are being serviced.
• plot a refrigeration cycle for refrigerants (R-22,
R-134a, and R-502) on a pressure/enthalpy diagram.
• plot a refrigeration cycle on a pressure/enthalpy dia-
gram for refrigerant blends R-404A and R-410A.
• plot a refrigeration cycle on a pressure/enthalpy
diagram for refrigerant blend (R-407C) that has a
noticeable temperature glide.
SAFETY ChECklIST
• Areas in which there could be potential refrigerant
leaks should be ventilated.
• Extra precautions should be taken to ensure that no
refrigerant leaks occur near an open flame.
• Refrigerants are stored in pressurized containers and
should be handled with care. Goggles with side shields
and gloves should be worn when checking pressures and
when transferring refrigerants from the container to a
system or from the system to an approved container.
AhRI CURRICUlUM GUIDE
COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
• INTRODUCTION
Introduction to Refrigeration
• PRINCIPLES OF THERMODYNAMICS AND
HEAT TRANSFER
Matter and Heat Behavior
Fluids and Pressures
Refrigeration Cycle/Diagrams
• REFRIGERANT RECOVERY
Refrigerant Recovery, Recycling, and Reclamation
Methods
Refrigerant Recovery, Recycling, and Reclamation
Equipment
• REFRIGERANTS AND LUBRICANTS
Refrigerants
• REGULATIONS
Regulations Affecting Ozone Depletion
EXERCISES (lAB MANUAl)
Exercises 3-1, 3-2, and 3-3
UNIT 3 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. Warm food, air leakage when door is opened, con-
duction through the walls.
Loading page 10...
Refrigeration and Refrigerants 7
2. BOX TEMPERATURES: Low temperature (0°F and
below), medium temperature (35°F to 45°F); high
temperatures are above 45°F.
3. B.
4. Warm liquid refrigerant is pumped through a me-
tering device into a coil (evaporator). Part of this re-
frigerant flashes to a vapor, becoming much cooler.
The medium to be cooled gives heat up to the cold
refrigerant, causing the remaining liquid refriger-
ant to boil to a vapor. This vaporized refrigerant is
then compressed by the compressor and pumped
to another coil called the condenser. The condenser
is where hot refrigerant vapor is condensed to a
warm liquid by giving up heat. The warm liquid
then goes to the metering device to be metered
into the evaporator for another trip through
the cycle.
5. If the pressure is decreased, the boiling temperature
is decreased. If the pressure is increased, the boiling
temperature is increased.
6. It absorbs heat into the refrigeration system. This
heat was in the product to be cooled.
7. Compresses the vapors from the evaporator and
suction line and then pumps these vapors to the
condenser, where they are condensed.
8. A superheated vapor that no longer corresponds to
a temperature/pressure relationship. When heat en-
ergy is added, superheated vapor takes on sensible
heat and will increase in temperature. This happens
because there is no liquid present to boil off and
cause vapor pressure.
9. A.
10. D.
11. 100% liquid that is cooler than the condensing satu-
ration temperature is called a subcooled liquid. If heat
energy is removed from a subcooled liquid, the liquid
will go through a sensible heat change and drop in
temperature.
12. A.
13. B.
14. If any heat energy is taken away from a sat u-
rated liquid, the liquid will become a subcooled
liquid. If any heat energy is added to a saturated
liquid, some of the liquid will flash into vapor. If
any heat energy is taken away from a saturated
vapor, the vapor will start to condense to a satu-
rated liquid and go through a latent phase change.
If any heat energy is added to a saturated vapor,
the vapor will become superheated and take on
sensible heat.
15. Desuperheating a vapor means that the superheated
vapor is losing superheat and decreasing in tem-
perature. The vapor is going through a sensible heat
change and getting closer to the saturation tempera-
ture for a certain corresponding pressure.
16. Heat is removed from it and it changes from a
vapor to a liquid. Both sensible and latent heat are
removed in the condenser.
17. The heat is transferred to a medium such as air or water.
18. D.
19. Adiabatic expansion is liquid expanding without a
net loss or gain in total heat energy, or enthalpy.
20. Flash gas happens at the entrance to the evapora-
tor. The liquid exiting the metering device has to be
cooled down to the evaporating temperature. This
same liquid flashes and cools itself to the evaporating
temperature. The more flash gas, the less refrigeration
effect there is.
21. Quality means percent vapor. A refrigerant with a
30% quality is 30% vapor and 70% liquid.
22. A reciprocating compressor has pistons that move
back and forth in a reciprocating motion, and a
rotary compressor has a rotating, drum-like piston
that turns in a cylinder.
23. R-12 White R-401A Coral red
R-22 Green R-402B Olive
R-502 Light purple R-410A Rose
R-134a Light sky blue R-404A Orange
R-11 Orange R-407C Med. brown
24. Enthalpy describes how much heat content in Btu/lb
a substance has from some starting point.
25. A pure compound is a substance formed in definite
proportions by weight with only one molecule present.
Examples of pure compounds are R-134a and R-22.
26. The net refrigeration effect is expressed in Btu/lb and is
the quantity of heat that the refrigerant absorbs from
the refrigerated space to produce useful cooling.
27. The total amount of heat energy, in Btu/h, that is gener-
ated or absorbed into the refrigeration system outside
of the evaporator is the sum of the heat of compression
(HOC) and the heat picked up by the refrigerant in
the suction line. Heat added to or generated within the
system outside of the evaporator can be calculated by
determining the difference in heat content between
the refrigerant at the outlet of the evaporator, point C
on the completed pressure/enthalpy chart, and the heat
content of the refrigerant at the outlet of the compres-
sor, point E on the completed pressure/enthalpy chart.
28. Flash gas occurs because the refrigerant entering the
evaporator from the metering device must be cooled to
the evaporating temperature before the remaining liq-
uid can evaporate in the evaporator and produce useful
cooling as part of the net refrigeration effect. The heat
absorbed in the flash gas does not contribute to the net
refrigeration effect because it comes from the liquid as
it partially changes phase to a liquid/vapor mixture.
29. Temperature glide refers to the fact that the refriger-
ant blend has many temperatures as it evaporates and
/or condenses at a given pressure. Temperature glide is
also defined as the temperature difference between the
2. BOX TEMPERATURES: Low temperature (0°F and
below), medium temperature (35°F to 45°F); high
temperatures are above 45°F.
3. B.
4. Warm liquid refrigerant is pumped through a me-
tering device into a coil (evaporator). Part of this re-
frigerant flashes to a vapor, becoming much cooler.
The medium to be cooled gives heat up to the cold
refrigerant, causing the remaining liquid refriger-
ant to boil to a vapor. This vaporized refrigerant is
then compressed by the compressor and pumped
to another coil called the condenser. The condenser
is where hot refrigerant vapor is condensed to a
warm liquid by giving up heat. The warm liquid
then goes to the metering device to be metered
into the evaporator for another trip through
the cycle.
5. If the pressure is decreased, the boiling temperature
is decreased. If the pressure is increased, the boiling
temperature is increased.
6. It absorbs heat into the refrigeration system. This
heat was in the product to be cooled.
7. Compresses the vapors from the evaporator and
suction line and then pumps these vapors to the
condenser, where they are condensed.
8. A superheated vapor that no longer corresponds to
a temperature/pressure relationship. When heat en-
ergy is added, superheated vapor takes on sensible
heat and will increase in temperature. This happens
because there is no liquid present to boil off and
cause vapor pressure.
9. A.
10. D.
11. 100% liquid that is cooler than the condensing satu-
ration temperature is called a subcooled liquid. If heat
energy is removed from a subcooled liquid, the liquid
will go through a sensible heat change and drop in
temperature.
12. A.
13. B.
14. If any heat energy is taken away from a sat u-
rated liquid, the liquid will become a subcooled
liquid. If any heat energy is added to a saturated
liquid, some of the liquid will flash into vapor. If
any heat energy is taken away from a saturated
vapor, the vapor will start to condense to a satu-
rated liquid and go through a latent phase change.
If any heat energy is added to a saturated vapor,
the vapor will become superheated and take on
sensible heat.
15. Desuperheating a vapor means that the superheated
vapor is losing superheat and decreasing in tem-
perature. The vapor is going through a sensible heat
change and getting closer to the saturation tempera-
ture for a certain corresponding pressure.
16. Heat is removed from it and it changes from a
vapor to a liquid. Both sensible and latent heat are
removed in the condenser.
17. The heat is transferred to a medium such as air or water.
18. D.
19. Adiabatic expansion is liquid expanding without a
net loss or gain in total heat energy, or enthalpy.
20. Flash gas happens at the entrance to the evapora-
tor. The liquid exiting the metering device has to be
cooled down to the evaporating temperature. This
same liquid flashes and cools itself to the evaporating
temperature. The more flash gas, the less refrigeration
effect there is.
21. Quality means percent vapor. A refrigerant with a
30% quality is 30% vapor and 70% liquid.
22. A reciprocating compressor has pistons that move
back and forth in a reciprocating motion, and a
rotary compressor has a rotating, drum-like piston
that turns in a cylinder.
23. R-12 White R-401A Coral red
R-22 Green R-402B Olive
R-502 Light purple R-410A Rose
R-134a Light sky blue R-404A Orange
R-11 Orange R-407C Med. brown
24. Enthalpy describes how much heat content in Btu/lb
a substance has from some starting point.
25. A pure compound is a substance formed in definite
proportions by weight with only one molecule present.
Examples of pure compounds are R-134a and R-22.
26. The net refrigeration effect is expressed in Btu/lb and is
the quantity of heat that the refrigerant absorbs from
the refrigerated space to produce useful cooling.
27. The total amount of heat energy, in Btu/h, that is gener-
ated or absorbed into the refrigeration system outside
of the evaporator is the sum of the heat of compression
(HOC) and the heat picked up by the refrigerant in
the suction line. Heat added to or generated within the
system outside of the evaporator can be calculated by
determining the difference in heat content between
the refrigerant at the outlet of the evaporator, point C
on the completed pressure/enthalpy chart, and the heat
content of the refrigerant at the outlet of the compres-
sor, point E on the completed pressure/enthalpy chart.
28. Flash gas occurs because the refrigerant entering the
evaporator from the metering device must be cooled to
the evaporating temperature before the remaining liq-
uid can evaporate in the evaporator and produce useful
cooling as part of the net refrigeration effect. The heat
absorbed in the flash gas does not contribute to the net
refrigeration effect because it comes from the liquid as
it partially changes phase to a liquid/vapor mixture.
29. Temperature glide refers to the fact that the refriger-
ant blend has many temperatures as it evaporates and
/or condenses at a given pressure. Temperature glide is
also defined as the temperature difference between the
Loading page 11...
8 Unit 3
saturated vapor temperature and the saturated liquid
temperature of the refrigerant at a constant pressure.
30. A zeotropic refrigerant blend is a blend of two or
more refrigerants that will change in temperature
and volumetric composition as they evaporate or
condense at a constant pressure. Zeotropic blends
have a very large, noticeable temperature glide. An
example is R-407C.
31. A near-azeotropic refrigerant blend is a blend of
two or more refrigerants that have a small change
in temperature and volumetric composition as they
evaporate or condense at a constant pressure. Their
temperature glide and fractionation is sometimes
unnoticeable. Examples are R-404A and R-410A.
UNIT 3 ANSWERS TO REVIEW TEST
QUESTIONS (lAB MANUAl)
1. D.
2. B.
3. B.
4. C.
5. C.
6. A.
7. A.
8. A.
9. A.
10. A.
11. A.
12. C.
13. B.
14. D.
15. D.
16. C.
ANSWERS TO EXERCISE 3-1
1. The evaporator is a heat exchanger that absorbs
heat into the refrigeration system. It is in the evapo-
rator where the refrigerant phase changes from a
liquid to a vapor.
2. The compressor is a vapor pump that pumps the heat
laden refrigerant through the refrigeration system. It
reduces the pressure on the low side of the system and
increases the pressure on the high side of the system.
3. The condenser rejects both sensible and latent heat
from the refrigeration system.
4. The metering device is a restriction in the system
that meters subcooled liquid from the liquid line to
the evaporator.
17. B.
18. D.
19. C.
20. C.
21. B.
22. A.
23. D.
24. C.
25. A.
26. D.
27. C.
28. A.
29. C.
30. A.
ANSWERS TO EXERCISE 3-2
Refrigerant Class Cylinder Color Safety Classification
R-134a HFC light sky blue A1
R-22 HCFC light green A1
R-404A HFC orange A1
R-32 HFC white/red stripe A2
R-407C HFC medium brown A1/A1
R-124 HCFC dark green A1
R-401C HCFC aqua A1/A1
R-125 HFC tan A1
R-407A HFC bright green A1/A1
R-502 CFC lavender A1
R-407B HFC cream A1/A1
R-143a HFC white/red stripe A2
R-402A HCFC sand A1/A1
R-402B HCFC olive A1/A1
R-152a HFC white/red stripe A2
R-406A HCFC light grey-green A1/A2
R-500 CFC yellow A1
R-290 HC red A3
R-123 HCFC light grey-blue B1
R-11 CFC orange A1
R-12 CFC white A1
saturated vapor temperature and the saturated liquid
temperature of the refrigerant at a constant pressure.
30. A zeotropic refrigerant blend is a blend of two or
more refrigerants that will change in temperature
and volumetric composition as they evaporate or
condense at a constant pressure. Zeotropic blends
have a very large, noticeable temperature glide. An
example is R-407C.
31. A near-azeotropic refrigerant blend is a blend of
two or more refrigerants that have a small change
in temperature and volumetric composition as they
evaporate or condense at a constant pressure. Their
temperature glide and fractionation is sometimes
unnoticeable. Examples are R-404A and R-410A.
UNIT 3 ANSWERS TO REVIEW TEST
QUESTIONS (lAB MANUAl)
1. D.
2. B.
3. B.
4. C.
5. C.
6. A.
7. A.
8. A.
9. A.
10. A.
11. A.
12. C.
13. B.
14. D.
15. D.
16. C.
ANSWERS TO EXERCISE 3-1
1. The evaporator is a heat exchanger that absorbs
heat into the refrigeration system. It is in the evapo-
rator where the refrigerant phase changes from a
liquid to a vapor.
2. The compressor is a vapor pump that pumps the heat
laden refrigerant through the refrigeration system. It
reduces the pressure on the low side of the system and
increases the pressure on the high side of the system.
3. The condenser rejects both sensible and latent heat
from the refrigeration system.
4. The metering device is a restriction in the system
that meters subcooled liquid from the liquid line to
the evaporator.
17. B.
18. D.
19. C.
20. C.
21. B.
22. A.
23. D.
24. C.
25. A.
26. D.
27. C.
28. A.
29. C.
30. A.
ANSWERS TO EXERCISE 3-2
Refrigerant Class Cylinder Color Safety Classification
R-134a HFC light sky blue A1
R-22 HCFC light green A1
R-404A HFC orange A1
R-32 HFC white/red stripe A2
R-407C HFC medium brown A1/A1
R-124 HCFC dark green A1
R-401C HCFC aqua A1/A1
R-125 HFC tan A1
R-407A HFC bright green A1/A1
R-502 CFC lavender A1
R-407B HFC cream A1/A1
R-143a HFC white/red stripe A2
R-402A HCFC sand A1/A1
R-402B HCFC olive A1/A1
R-152a HFC white/red stripe A2
R-406A HCFC light grey-green A1/A2
R-500 CFC yellow A1
R-290 HC red A3
R-123 HCFC light grey-blue B1
R-11 CFC orange A1
R-12 CFC white A1
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Refrigeration and Refrigerants 9
ANSWERS TO EXERCISE 3-3
Given a temperature, determine the corresponding pressure.
R-22 at 40° has a corresponding pressure of? 68.5 psig
R-22 at 100° has a corresponding pressure of? 195.9 psig
R-134a at 40° has a corresponding pressure of? 35.1 psig
R-502 at 10° has a corresponding pressure of? 41 psig
R-502 at 110° has a corresponding pressure of? 247.9 psig
R-404A at −10° has a corresponding pressure of? 24.3 psig
R-404A at 120° has a corresponding pressure of? 310.7 psig
R-410A at 45° has a corresponding pressure of? 130 psig
R-410A at 115° has a corresponding pressure of? 390.5 psig
Given a pressure, determine the corresponding temperature
R-22 at 226.4 psig has a corresponding temperature of? 110 °F
R-22 at 77.6 psig has a corresponding temperature of? 46 °F
R-134a at 198.7 psig has a corresponding temperature of? 130 °F
R-134a at 31.3 psig has a corresponding temperature of? 36 °F
R-502 at 9.2 psig has a corresponding temperature of? −30 °F
R-502 at 408.4 psig has a corresponding temperature of? 150 °F
R-404A at 3.1 in. Hg has a corresponding temperature of? −55 °F
R-404A at 148.5 psig has a corresponding temperature of? 70 °F
R-410A at 90.2 psig has a corresponding temperature of? 26 °F
R-410A at 317.1 psig has a corresponding temperature of? 100 °F
ANSWERS TO EXERCISE 3-3
Given a temperature, determine the corresponding pressure.
R-22 at 40° has a corresponding pressure of? 68.5 psig
R-22 at 100° has a corresponding pressure of? 195.9 psig
R-134a at 40° has a corresponding pressure of? 35.1 psig
R-502 at 10° has a corresponding pressure of? 41 psig
R-502 at 110° has a corresponding pressure of? 247.9 psig
R-404A at −10° has a corresponding pressure of? 24.3 psig
R-404A at 120° has a corresponding pressure of? 310.7 psig
R-410A at 45° has a corresponding pressure of? 130 psig
R-410A at 115° has a corresponding pressure of? 390.5 psig
Given a pressure, determine the corresponding temperature
R-22 at 226.4 psig has a corresponding temperature of? 110 °F
R-22 at 77.6 psig has a corresponding temperature of? 46 °F
R-134a at 198.7 psig has a corresponding temperature of? 130 °F
R-134a at 31.3 psig has a corresponding temperature of? 36 °F
R-502 at 9.2 psig has a corresponding temperature of? −30 °F
R-502 at 408.4 psig has a corresponding temperature of? 150 °F
R-404A at 3.1 in. Hg has a corresponding temperature of? −55 °F
R-404A at 148.5 psig has a corresponding temperature of? 70 °F
R-410A at 90.2 psig has a corresponding temperature of? 26 °F
R-410A at 317.1 psig has a corresponding temperature of? 100 °F
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10
General Safety Practices
Unit 4
Safety is discussed in great detail throughout the book,
but this unit provides safety precautions necessary when
working with pressure vessels and piping, electrical haz-
ards, heat, cold, mechanical equipment, heavy objects,
and chemicals.
OBJECTIVES
After studying this unit, the student should be able to:
• describe proper procedures for working with pressur-
ized systems and vessels, electrical energy, heat, cold,
rotating machinery, ladders, fire risks, building evacu-
ation, refrigerants and other chemicals; moving heavy
objects; and for utilizing proper ventilation.
AHRI CURRICULUM GUIDE
COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
• SAFETY
Personal Safety and Work Practices
Handling of Pressurized Fluids
Handling of Hazardous Substances
Electrical Safety
UNIT 4 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. When charging liquid refrigerant into a system.
2. C.
3. Because of the great internal pressure in a nitrogen
tank, the pressure must be reduced.
4. An explosion can occur.
5. Possible frostbite or frozen skin.
6. Heart.
7. Heart rhythm problems and burns.
8. By using heat shields.
9. Stand to the side in case loose parts may fly. Check
for loose parts at the coupling and shaft.
10. Ground.
11. Using dollies and plywood on which to move the
equipment.
12. Determining that the chemicals will not corrode
the condenser and should be washed off with great
caution.
13. Acids.
14. B-3.
15. The letters A, B, and C represent the types of fire extin-
guishers for different kinds of fires. Type A can be used
on trash, wood, and paper. Type B is for liquids that
are on fire. Type C is for electrical equipment fires.
UNIT 4 ANSWERS TO REVIEW TEST
QUESTIONS (LAB MANUAL)
1. C.
2. C.
3. A.
4. A.
5. A.
6. B.
7. C.
8. A.
9. B.
10. A.
11. A.
12. A.
General Safety Practices
Unit 4
Safety is discussed in great detail throughout the book,
but this unit provides safety precautions necessary when
working with pressure vessels and piping, electrical haz-
ards, heat, cold, mechanical equipment, heavy objects,
and chemicals.
OBJECTIVES
After studying this unit, the student should be able to:
• describe proper procedures for working with pressur-
ized systems and vessels, electrical energy, heat, cold,
rotating machinery, ladders, fire risks, building evacu-
ation, refrigerants and other chemicals; moving heavy
objects; and for utilizing proper ventilation.
AHRI CURRICULUM GUIDE
COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
• SAFETY
Personal Safety and Work Practices
Handling of Pressurized Fluids
Handling of Hazardous Substances
Electrical Safety
UNIT 4 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. When charging liquid refrigerant into a system.
2. C.
3. Because of the great internal pressure in a nitrogen
tank, the pressure must be reduced.
4. An explosion can occur.
5. Possible frostbite or frozen skin.
6. Heart.
7. Heart rhythm problems and burns.
8. By using heat shields.
9. Stand to the side in case loose parts may fly. Check
for loose parts at the coupling and shaft.
10. Ground.
11. Using dollies and plywood on which to move the
equipment.
12. Determining that the chemicals will not corrode
the condenser and should be washed off with great
caution.
13. Acids.
14. B-3.
15. The letters A, B, and C represent the types of fire extin-
guishers for different kinds of fires. Type A can be used
on trash, wood, and paper. Type B is for liquids that
are on fire. Type C is for electrical equipment fires.
UNIT 4 ANSWERS TO REVIEW TEST
QUESTIONS (LAB MANUAL)
1. C.
2. C.
3. A.
4. A.
5. A.
6. B.
7. C.
8. A.
9. B.
10. A.
11. A.
12. A.
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11
Tools and Equipment
Unit 5
This unit describes heating, air-conditioning, refrigera-
tion air system balancing, and energy auditing tools and
equipment and their use, including general hand tools,
specialized hand tools, specialized digital tools, web-based
instruments and tools, and specialized service and instal-
lation equipment.
OBJECTIVES
After studying this unit, the student should be able to:
• describe hand tools used by the air-conditioning,
heating, and refrigeration technician.
• describe equipment used to install and service air-
conditioning, heating, and refrigeration systems.
• describe equipment and tools used by residential
energy auditors.
SafETy ChECklIST
• Tools and equipment should be used only for the job
for which they were designed. Other use may dam-
age the tool or equipment and may be unsafe for the
technician.
ahRI CURRICUlUM GUIDE
COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
• TOOLS AND EQUIPMENT
Hand Tools and Accessories
Electrical Testing Devices/Meters
Refrigeration: Servicing and Testing Equipment
Heating: Servicing and Testing Equipment
Airflow: Measuring and Testing Equipment
UNIT 5 aNSWERS
TO REVIEW QUESTIONS (TEXT)
1. Phillips and straight or slot blade; also Keystone,
cabinet, Torx, clutch head, hex head, Read and
Prince (Frearson) square.
2. Socket with ratchet handle, open end, box end, com-
bination, adjustable open end; also ratchet box, pipe.
3. To drive hex head screws that fasten panels on air-
conditioning, heating, and refrigeration cabinets.
4. General-purpose, needle-nose, side cutting, slip joint;
also locking.
5. Spring type—a coil spring that can be used inside or
outside the tubing to be bent to keep tubing from
kinking; lever type—a lever is used to help apply
pressure to bend tubing and avoid kinking.
6. C.
7. C.
8. A.
9. Electronic, fluorescent system with ultraviolet lamp,
halide torch, bubbles, and ultrasonic.
10. Compound gauge, high-pressure gauge, manifold,
valves, and hoses.
11. Glass stem, pocket dial, pocket digital; also elec-
tronic and recording type.
12. To solder electrical connections.
13. Soldering and brazing.
14. Uses wet-bulb/dry-bulb principle to obtain relative
humidity readings.
15. To balance duct systems, check fan and blower char-
acteristics, and make static pressure measurements.
16. To make flue-gas analyses to determine combustion
efficiency in gas or oil furnaces.
17. To check the pressure of the flue gas in gas and oil
furnaces.
18. Voltage, resistance, current in milliamperes.
19. To accurately charge refrigerant by weight.
20. It is illegal to intentionally vent refrigerant to the
air. Refrigerant is recovered from a system so that
the system can be worked on without venting the
refrigerant to the air.
UNIT 5 aNSWERS TO REVIEW TEST
QUESTIONS (laB MaNUal)
1. A.
2. C.
3. A.
4. C.
5. D.
6. D.
7. C.
8. C.
9. A.
10. A.
11. A.
12. D.
13. D.
14. D.
15. D.
16. C.
Tools and Equipment
Unit 5
This unit describes heating, air-conditioning, refrigera-
tion air system balancing, and energy auditing tools and
equipment and their use, including general hand tools,
specialized hand tools, specialized digital tools, web-based
instruments and tools, and specialized service and instal-
lation equipment.
OBJECTIVES
After studying this unit, the student should be able to:
• describe hand tools used by the air-conditioning,
heating, and refrigeration technician.
• describe equipment used to install and service air-
conditioning, heating, and refrigeration systems.
• describe equipment and tools used by residential
energy auditors.
SafETy ChECklIST
• Tools and equipment should be used only for the job
for which they were designed. Other use may dam-
age the tool or equipment and may be unsafe for the
technician.
ahRI CURRICUlUM GUIDE
COMPETENCIES
Background and related information is included in this
unit for many of the competencies listed in the follow-
ing areas of training in the AHRI Curriculum Guide:
• TOOLS AND EQUIPMENT
Hand Tools and Accessories
Electrical Testing Devices/Meters
Refrigeration: Servicing and Testing Equipment
Heating: Servicing and Testing Equipment
Airflow: Measuring and Testing Equipment
UNIT 5 aNSWERS
TO REVIEW QUESTIONS (TEXT)
1. Phillips and straight or slot blade; also Keystone,
cabinet, Torx, clutch head, hex head, Read and
Prince (Frearson) square.
2. Socket with ratchet handle, open end, box end, com-
bination, adjustable open end; also ratchet box, pipe.
3. To drive hex head screws that fasten panels on air-
conditioning, heating, and refrigeration cabinets.
4. General-purpose, needle-nose, side cutting, slip joint;
also locking.
5. Spring type—a coil spring that can be used inside or
outside the tubing to be bent to keep tubing from
kinking; lever type—a lever is used to help apply
pressure to bend tubing and avoid kinking.
6. C.
7. C.
8. A.
9. Electronic, fluorescent system with ultraviolet lamp,
halide torch, bubbles, and ultrasonic.
10. Compound gauge, high-pressure gauge, manifold,
valves, and hoses.
11. Glass stem, pocket dial, pocket digital; also elec-
tronic and recording type.
12. To solder electrical connections.
13. Soldering and brazing.
14. Uses wet-bulb/dry-bulb principle to obtain relative
humidity readings.
15. To balance duct systems, check fan and blower char-
acteristics, and make static pressure measurements.
16. To make flue-gas analyses to determine combustion
efficiency in gas or oil furnaces.
17. To check the pressure of the flue gas in gas and oil
furnaces.
18. Voltage, resistance, current in milliamperes.
19. To accurately charge refrigerant by weight.
20. It is illegal to intentionally vent refrigerant to the
air. Refrigerant is recovered from a system so that
the system can be worked on without venting the
refrigerant to the air.
UNIT 5 aNSWERS TO REVIEW TEST
QUESTIONS (laB MaNUal)
1. A.
2. C.
3. A.
4. C.
5. D.
6. D.
7. C.
8. C.
9. A.
10. A.
11. A.
12. D.
13. D.
14. D.
15. D.
16. C.
Loading page 15...
12
Fasteners
Unit 6
This unit describes nails, staples, rivets, and wood screws,
including tapping and machine screws. Thread sizes and
other identifying data are covered. Other fasteners de-
scribed are set screws, anchor shields, wall anchors, toggle
bolts, threaded rod, angle steel, and masonry fasteners.
Miscellaneous fasteners discussed are the cotter pin, pipe
hook, pipe strap, perforated strap, nylon strap, grille clip,
solderless terminals, and screw-on wire connectors.
OBJECTIVES
After studying this unit, the student should be able to:
• identify common fasteners used with wood.
• identify common fasteners used on hollow walls.
• identify common fasteners used with sheet metal.
• write and explain a typical tapping screw dimension.
• identify typical machine screw heads.
• write and explain each part of a machine screw
thread dimension.
• identify and describe fasteners used in masonry
applications.
• describe hanging and securing devices for piping, tubing,
and ductwork.
• describe various types of other commonly used fasteners.
• describe solderless terminals and screw-on wire
connectors.
SAFETY ChECklIST
• When staples are used to fasten a wire in place, do not
hammer them too tightly as they may damage the wire.
• When using fasteners, make sure that all materials
are strong enough for the purpose for which they are
being used.
• Wear goggles whenever drilling holes and when
cleaning out holes.
• Do not use powder-actuated systems without the
proper training.
• When installing fasteners, be sure to follow all instal-
lation instructions carefully.
• As an air-conditioning (heating and cooling) and
refrigeration technician, you need to know about
different types of fasteners and various fastening
systems. Knowing about different fasteners, includ-
ing their intended use as well as their limitations,
will help make sure that you use the right fastener or
system to securely install and mount all equipment,
system components, and materials.
EXERCISES (lAB MANUAl)
Exercises 6-1 and 6-2
UNIT 6 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. Common, finishing, roofing; also masonry.
2. Penny.
3. d.
4. D.
5. D.
6. Hollow wall anchor, toggle bolt, self-drilling drywall
anchors, plastic toggle drywall anchors.
7. Hardened steel.
8. U-shape to fasten wire in place; outward clinch to
fasten insulation and ductboard.
9. Drill a hole in both pieces of metal the size of the
rivet diameter, insert the pin rivet with pointed end
facing out, place the nozzle of the riveting tool over
the pin, and squeeze the handles.
10. 6–20 3 1/2, Type AB slotted hex.
6 5 outside thread diameter.
20 5 number of threads per inch.
1/2 5 length of screw.
Type AB 5 type of point.
Slotted hex 5 type of head.
11. See Figure 6.12 in the text.
12. 5
/16218 UNC-2.
5 /16 5 outside diameter.
18 5 number of threads per inch.
UNC 5 Unified thread series (Unified National
Coarse).
2 5 class of fit.
13. Drill a hole into both pieces of metal the approxi-
mate size of the thread root diameter; turn the screw
into the hole with a conventional screwdriver or elec-
tric drill with appropriate screwdriver bit or chuck.
14. A.
15. A tapping screw has an end slightly tapered to the
root diameter; a self-drilling screw has a point and
drill feature at the end.
16. Flat, cone, oval; also cup, dog, half-dog.
17. To fasten objects to masonry or in some cases to
hollow walls.
Fasteners
Unit 6
This unit describes nails, staples, rivets, and wood screws,
including tapping and machine screws. Thread sizes and
other identifying data are covered. Other fasteners de-
scribed are set screws, anchor shields, wall anchors, toggle
bolts, threaded rod, angle steel, and masonry fasteners.
Miscellaneous fasteners discussed are the cotter pin, pipe
hook, pipe strap, perforated strap, nylon strap, grille clip,
solderless terminals, and screw-on wire connectors.
OBJECTIVES
After studying this unit, the student should be able to:
• identify common fasteners used with wood.
• identify common fasteners used on hollow walls.
• identify common fasteners used with sheet metal.
• write and explain a typical tapping screw dimension.
• identify typical machine screw heads.
• write and explain each part of a machine screw
thread dimension.
• identify and describe fasteners used in masonry
applications.
• describe hanging and securing devices for piping, tubing,
and ductwork.
• describe various types of other commonly used fasteners.
• describe solderless terminals and screw-on wire
connectors.
SAFETY ChECklIST
• When staples are used to fasten a wire in place, do not
hammer them too tightly as they may damage the wire.
• When using fasteners, make sure that all materials
are strong enough for the purpose for which they are
being used.
• Wear goggles whenever drilling holes and when
cleaning out holes.
• Do not use powder-actuated systems without the
proper training.
• When installing fasteners, be sure to follow all instal-
lation instructions carefully.
• As an air-conditioning (heating and cooling) and
refrigeration technician, you need to know about
different types of fasteners and various fastening
systems. Knowing about different fasteners, includ-
ing their intended use as well as their limitations,
will help make sure that you use the right fastener or
system to securely install and mount all equipment,
system components, and materials.
EXERCISES (lAB MANUAl)
Exercises 6-1 and 6-2
UNIT 6 ANSWERS
TO REVIEW QUESTIONS (TEXT)
1. Common, finishing, roofing; also masonry.
2. Penny.
3. d.
4. D.
5. D.
6. Hollow wall anchor, toggle bolt, self-drilling drywall
anchors, plastic toggle drywall anchors.
7. Hardened steel.
8. U-shape to fasten wire in place; outward clinch to
fasten insulation and ductboard.
9. Drill a hole in both pieces of metal the size of the
rivet diameter, insert the pin rivet with pointed end
facing out, place the nozzle of the riveting tool over
the pin, and squeeze the handles.
10. 6–20 3 1/2, Type AB slotted hex.
6 5 outside thread diameter.
20 5 number of threads per inch.
1/2 5 length of screw.
Type AB 5 type of point.
Slotted hex 5 type of head.
11. See Figure 6.12 in the text.
12. 5
/16218 UNC-2.
5 /16 5 outside diameter.
18 5 number of threads per inch.
UNC 5 Unified thread series (Unified National
Coarse).
2 5 class of fit.
13. Drill a hole into both pieces of metal the approxi-
mate size of the thread root diameter; turn the screw
into the hole with a conventional screwdriver or elec-
tric drill with appropriate screwdriver bit or chuck.
14. A.
15. A tapping screw has an end slightly tapered to the
root diameter; a self-drilling screw has a point and
drill feature at the end.
16. Flat, cone, oval; also cup, dog, half-dog.
17. To fasten objects to masonry or in some cases to
hollow walls.
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