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Solution Manual For Refrigeration and Air Conditioning Technology, 8th Edition

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    ’s Manual to Accompany Refrigeration and Air Conditioning Technology 8 th Edition Concepts, Procedures, and Troubleshooting Techniques John A. Tomczyk Eugene Silberstein William C. Whitman William M. Johnson SOLUTION MANUAL

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    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

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    iv Contents Unit 45 Domestic Refrigerators and Freezers 118 Unit 46 Room Air Conditioners 121 Unit 47 High-pressure, Low- p ressure, and Absorption Chilled-Water Systems 123 Unit 48 Cooling Towers and p umps 126 Unit 49 Operation, Maintenance, and Troubleshooting of Chilled-Water Air-Conditioning Systems 128 Unit 50 Commercial p ackaged Rooftop, Variable Refrigerant Flow, and Variable Air Volume Systems 130 PART II Lecture Outlines 133 PART III Correlation Guide 365

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    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 Ch EC kl IST ● 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. A h RI CURRICU l UM 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 ( l AB MANUA l ) 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

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    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 COMP l ETED TEMPERATURE CONVERSION C h ART 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 ( l AB MA NUA l) 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.

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    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 Ch EC kl IST ● ● 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 ( l AB MANUA l ) 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/ft 3 5 0.000826 ft 3 /lb. 12. Density 5 1  (0.001865 ft 3 /lb) 5 536.19 lb/ft 3 . 13. Specific gravity 5 171 lb/ft 3  62.4 lb/ft 3 5 2.74. 14. Density is (4 lb  10 ft 3 ) 5 0.4 lb/ft 3 . 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.

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    4 Unit 2 29. The pressure is constant so V T V T 1 1 2 2  . V V T T 2 1 2 1  V 2 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 V 2 1 1 2 1 2  P 2 10 180 460     ( )( ) psig 14.696) (10.5 in R (65 46 3 ° ° 0 0) R(1.5 in 3 ° ) P 2 5 210.74 psia P 2 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 ft 3 80 ° F 2 50 psia 2,000 ft 3 75 ° F 50 psia (2291 ft 3 ) 130 ° F 3 40 psia 30 in 3 80 ° F 50 psia (24 ft 3 ) 80 ° F 4 (100 psia) 20 ft 3 500 R 200 psia 12 ft 3 600 R 5 100 psia 10 ft 3 600 R 100 psia 25 ft 3 (1500 R) 6 80 psia (150 ft 3 ) 400 R 150 psia 100 ft 3 500 R 7 150 psia 100 ft 3 (700 R) 300 psia 50 ft 3 700 R 8 80 psia 500 ft 3 600 R (160 psia) 100 ft 3 240 R COMP l ETED C h ART FROM EXERCISE 2-2 (Bolded values in parentheses represent the items that were to be filled in by the student.) Substance Density (lb/in 3 ) Density (oz/in 3 ) Density (lb/ft 3 ) 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. COMP l ETED C h ART 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 ( l AB MANUA l )

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    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. COMP l ETED C h ART 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.

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    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 Ch EC kl IST • 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. A h RI CURRICU l UM 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 ( l AB MANUA l ) 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.

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    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 - rat ed 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

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    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 ( l AB MANUA l ) 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

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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.

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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. Saf ET y Ch EC kl IST • 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. ah RI CURRICU l UM 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 a NSWERS 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 a NSWERS TO REVIEW TEST QUESTIONS ( la B M a NU al ) 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.

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    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 Ch EC kl IST • 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 ( l AB MANUA l ) 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 / 16 2 18 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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