Air Conditioning Engineering, Fifth Edition

Front Cover......Page 1
Air Conditioning Engineering......Page 4
Copyright Page......Page 5
Contents......Page 10
Preface to the Fifth Edition......Page 6
Preface to the First Edition......Page 8
Acknowledgement......Page 9
1.2 Comfort conditioning......Page 16
1.3 Industrial conditioning......Page 17
2.2 The composition of dry air......Page 18
2.3 Standards adopted......Page 20
2.4 Boyle\'s law......Page 21
2.5 Charles\' law......Page 22
2.6 The general gas law......Page 24
2.7 Dalton\'s law of partial pressure......Page 26
2.8 Saturation vapour pressure......Page 27
2.9 The vapour pressure of steam in moist air......Page 28
2.10 Moisture content and humidity ratio......Page 31
2.11 Percentage saturation......Page 33
2.12 Relative humidity......Page 34
2.13 Dew point......Page 35
2.14 Specific volume......Page 36
2.15 Enthalpy: thermodynamic background......Page 37
2.16 Enthalpy in practice......Page 38
2.17 Wet-bulb temperature......Page 40
2.18 Temperature of adiabatic saturation......Page 43
2.19 Non-ideal behaviour......Page 45
2.20 The triple point......Page 48
3.1 The psychrometric chart......Page 53
3.2 Mixtures......Page 54
3.3 Sensible heating and cooling......Page 57
3.4 Dehumidification......Page 59
3.5 Humidification......Page 63
3.6 Water injection......Page 67
3.7 Steam injection......Page 69
3.8 Cooling and dehumidification with reheat......Page 72
3.9 Pre-heat and humidification with reheat......Page 77
3.10 Mixing and adiabatic saturation with reheat......Page 81
3.11 The use of dry steam for humidification......Page 83
3.12 Supersaturation......Page 85
3.13 Dehumidification by sorption methods......Page 86
4.1 Metabolism and comfort......Page 95
4.2 Bodily mechanisms of heat transfer and thermostatic control......Page 96
4.3 Metabolic rates......Page 97
4.4 Clothing......Page 98
4.5 Environmental influences on comfort......Page 100
4.6 Other influences on comfort......Page 103
4.7 Fanger\'s comfort equation......Page 104
4.8 Synthetic comfort scales......Page 105
4.9 Measuring instruments......Page 107
4.10 Outdoor air requirements......Page 108
4.11 Indoor air quality......Page 109
4.12 The choice of inside design conditions......Page 111
4.13 Design temperatures and heat gains......Page 112
5.1 Climate......Page 119
5.2 Winds......Page 120
5.3 Local winds......Page 121
5.5 Mist and fog......Page 122
5.7 Diurnal temperature variation......Page 124
5.8 Diurnal variation of humidity......Page 125
5.9 Meteorological measurement......Page 127
5.11 The choice of outside design conditions......Page 130
6.1 Sensible heat removal......Page 135
6.2 The specific heat capacity of humid air......Page 138
6.3 Latent heat removal......Page 139
6.4 The slope of the room ratio line......Page 141
6.5 Heat gain arising from fan power......Page 147
6.6 Wasteful reheat......Page 148
6.7 The choice of a suitable supply state......Page 151
6.8 Warm air supply temperatures......Page 156
7.2 The physics of solar radiation......Page 159
7.3 Sky radiation......Page 160
7.4 Definitions......Page 161
7.5 The declination of the sun......Page 164
7.6 The altitude of the sun......Page 165
7.7 The azimuth of the sun......Page 167
7.8 The intensity of direct radiation on a surface......Page 168
7.9 The numerical value of direct radiation......Page 171
7.11 The geometry of shadows......Page 174
7.12 The transmission of solar radiation through glass......Page 176
7.13 The heat absorbed by glass......Page 178
7.14 Internal shading and double glazing......Page 183
7.15 Numerical values of scattered radiation......Page 184
7.16 Minor factors affecting solar gains......Page 185
7.17 Heat gain through walls......Page 190
7.18 Sol-air temperature......Page 192
7.19 Calculation of heat gain through a wall or roof......Page 193
7.20 Air conditioning load due to solar gain through glass......Page 199
7.21 Heat transfer to ducts......Page 205
7.22 Infiltration......Page 212
7.23 Electric lighting......Page 213
7.24 Occupants......Page 215
7.26 Business machines......Page 216
8.1 Cooling load and heat gains......Page 231
8.2 Cooling load for a whole building......Page 234
8.4 Cooling load offset by reheat......Page 235
8.5 The use of by-passed air instead of reheat......Page 240
8.6 Face and by-pass dampers......Page 242
8.7 Cooling in sequence with heating......Page 244
8.8 Hot deck--cold deck systems......Page 245
8.11 Diversification of load......Page 246
8.12 Load diagrams......Page 247
9.1 The basis of vapour compression refrigeration......Page 256
9.2 Thermodynamics and refrigeration......Page 258
9.3 The refrigerating effect......Page 264
9.4 The work done in compression......Page 268
9.5 Heat rejected at the condenser......Page 269
9.6 Coefficient of performance......Page 270
9.7 Actual vapour-compression cycle......Page 273
9.8 Pressure-volume relations......Page 276
9.9 Volumetric efficiency......Page 281
9.10 Thermosyphon cooling......Page 284
9.11 Refrigerants......Page 285
9.12 Ozone depletion effects......Page 287
9.14 Other methods of refrigeration......Page 289
9.15 Safety......Page 291
10.1 Distinction between cooler coils and air washers......Page 294
10.2 Cooler coil construction......Page 295
10.3 Parallel and contra-flow......Page 299
10.4 Contact factor......Page 301
10.5 Heat and mass transfer to cooler coils......Page 304
10.6 Sensible cooling......Page 309
10.7 Partial load operation......Page 313
10.8 The performance of a wild coil......Page 315
10.9 Sprayed cooler coils......Page 316
10.10 Free cooling......Page 318
10.12 Air washers......Page 319
11.1 Methods of rejecting heat......Page 326
11.2 Types of cooling tower......Page 328
11.3 Theoretical considerations......Page 330
11.4 Evaporative condensers......Page 332
11.5 Air-cooled condensers......Page 333
11.6 Automatic control......Page 334
11.7 Practical considerations......Page 336
12.1 The expansion valve......Page 341
12.2 The distributor......Page 345
12.4 Evaporators for liquid chilling......Page 346
12.5 Direct-expansion air cooler coils......Page 348
12.6 The reciprocating compressor......Page 351
12.7 The air-cooled condensing set......Page 354
12.8 Condensing set-evaporator match......Page 355
12.9 The control of direct-expansion cooler coils and condensing sets......Page 356
12.10 The performance of water chillers......Page 358
12.11 The screw compressor......Page 364
12.13 Centrifugal compressors......Page 367
12.14 The water-cooled condenser......Page 373
12.15 Piping and accessories......Page 374
12.16 Charging the system......Page 376
13.1 The principle of automatic control......Page 378
13.2 Definitions......Page 379
13.3 Measurement and lag......Page 381
13.4 Measurement elements......Page 382
13.5 Types of system......Page 386
13.8 Timed two-position control......Page 390
13.9 Floating action......Page 391
13.10 Simple proportional control......Page 393
13.11 Refined proportional control......Page 394
13.12 Automatic valves......Page 396
13.13 Automatic dampers......Page 405
13.14 Application......Page 406
13.16 Control by microprocessors and Building Management Systems (BMS and BEMS)......Page 410
14.1 Basic concepts......Page 414
14.2 Temperatures, pressures, heat quantities and flow rates for the lithium bromide-water cycle......Page 415
14.3 Coefficient of performance and cycle efficiency......Page 419
14.4 Practical considerations......Page 421
14.5 Other systems......Page 424
15.1 Viscous and turbulent flow......Page 426
15.2 Basic sizing......Page 430
15.3 Conversion from circular to rectangular section......Page 433
15.4 Energy changes in a duct system......Page 435
15.5 Velocity (dynamic) pressure......Page 437
15.7 The coefficient of entry (CE)......Page 438
15.8 The discharge of air from a duct system......Page 440
15.9 Airflow through a simple duct system......Page 441
15.10 Airflow through transition pieces......Page 442
15.11 Airflow around bends......Page 448
15.12 Airflow through supply branches......Page 451
15.13 Flow through suction branches......Page 452
15.14 Calculation of fan total and fan static pressure......Page 453
15.15 The interaction of fan and system characteristic curves......Page 458
15.16 The fan laws......Page 460
15.18 Margins......Page 462
15.19 Power-volume and efficiency-volume characteristics......Page 463
15.20 Fan testing......Page 467
15.21 The performance of air handling units......Page 468
15.22 Methods of varying fan capacity in a duct system......Page 470
15.23 The effect of opening and closing branch dampers......Page 474
15.24 Fans in parallel and series......Page 477
16.1 The need for ventilation......Page 483
16.2 The decay equation......Page 490
16.3 An application of the decay equation to changes of enthalpy......Page 497
17.1 Particle sizes......Page 503
17.2 Particle behaviour and collection......Page 504
17.3 Efficiency......Page 505
17.4 Classification according to efficiency......Page 510
17.6 Dry filters......Page 511
17.7 Electric filters......Page 513
17.10 Adsorption filters......Page 516
17.11 Safety......Page 518
Index......Page 522
CIBSE Psychrometric Chart......Page 531