Document 0gBMQa9vRDKVn94kYYK3br76n

HEATING VENTILATING AIR CONDITIONING GUIDE 1943 Cooling (continued) " ponds, 543 residential, 394 sensible, 417 surfaces, 92 systems, 395, 457 tower design, 546 tower performance, 553 units. 452 control, 662 defrosting, 454 design. 452 performance, 452 ratings, 454 types of, 453 Copper elbow equivalents. 317 tubing, radiating surface. 779 Core area. 590 Corrosion. 366 air washers, 368 industrial exhaust systems, 746 pipe, 366 Crack length used for computations, 121, 128 Crystallization control rate of, 728 Cylinder dryer, 746 D Dairy barn ventilation, 772 Dalton's law, 8 Damper, dampers, 386, 590 back pressure control, 661 Decibel. 625 Defrosting, 454 Degree day, 230.796 formula for, method, 234 operating unit. 239 unit fuel consumptions, 234 Degree of saturation, 19, 796 Dehumidification, 457, 844 air conditioning units, 443 control, 656 definitions and methods, 457 Dehydrating agents. 459 absorbents, 459, 462 adsorbents. 459 Dehydration, 457, 844 , coil selection. 526 controls, 656 definitions and methods, 457 economics, 472 economic comparisons, 473 equipment, 470 auxiliaries, 470 performance, 471 estimating loads. 469 liquid methods, 469 . .. location of equipment, 470 solid methods. 466 Density of air, 1, 845 Dew-point apparatus temperature, 33, 164, 405 temperature, 20 Dichlorodifiuoromethane. 478 / Direct - expansion coils, 507 fired unit heater, 434 indirect heating unit, 845 radiator, 845 return system, 312, 845 Direct current motors, 681 Disc fan. 575 Distribution of air, 595 (see A ir distribution) - District heating, 329 ; glossary of terms, 341 ' District heating (continued) piping, 329 conduits for, 331 _ inside, 335 overhead distribution, 334 sizes, 330 tunnels, 334 types of, 332 rates, 341 ' utilization. 343 Diverging vanes, 593 Domestic oil burners, 214 Door, doors coefficients of transmission. 115 leakage, 124 natural ventilation, 770 Down-feed ' one-pipe riser, 845 steam heating, 275 system, 845 Draft, drafts, 173 calculations, 187 control, 189 general equation, 197 head, 845 mechanical. 188 natural, 187 regulation, 173 requirements, 173 Drawing symbols, 856 Drip, drips, 308, 845.; Drum dryer, 746 Dry air, 1, 845 composition, 1 density, 1 filters, 568 specific enthalpy, 5 specific volume. 1 velocity head, 606 volume, 20 Dry-bulb temperature. 845 Dry cooling coils,- 417 Dry return, 845 Dryer, dryers agitated, 746 -- compartment, 746 cylinder, 746 drum. 746 festoon, 746 v high temperature, 760 induction, 746 rotary, 746 spray, 746 tower, 746 tunnel, 746 - vacuum, 746 Dryer calculations, 755 . Drying, 747 - ` design, 757 . estimating methods, 763 factors influencing, 752 general' rules for, 753 air circulation, 753 humidity, 753 temperature, 753 ; humidity, 753 mechanism of, 751 methods, 747 conduction, 749 - - convection, 749 estimating, 763 . radiant heat,. 747 omissions in the cycle, 752 radiant, 800 systems, 747 ventilation phase. 759 ' Dual duct. 414 Duct, ducts. 387,-615. , air velocities in, 741 approaches to outlets. 594 attenuation, 630 construction, 741 construction details, 620 ` design, 616 ., _ ^ xiv ik f/- -' ALPHABETICAL INDEX TO TECHNICAL DATA SECTION Duct, ducts (continued) details, 620 dual. 414 elbow friction losses, 611 friction losses, 606 . heat loss coefficients, 790 heat losses, 775, 791 lining, 635 . measurement of velocities, 676 noise transmitted, 627 proportioning the losses, 615 recirculating, 373 ' rectangular equivalents of round, 610 resistance, 742 sound absorbers, 631 symbols for drawing, 857, 858 system design, 740 Duct sizes, 615 air velocities, 616 equal friction, 618 general rules, 616 ' main trunk, 617 velocity method, 617 Dust, 561. 564, 845 . concentrations, 558 determination. 678 filters. 743 nature's catcher, 562 E Economizer control, 659 ' Effective temperature, '58, 845 (see Temperature) chart, 57 index, 58 Ejector nozzles, 597 Elbow attenuation. 630 copper equivalents, 317 friction duct losses, 606 . . iron equivalents, 317 Electric, electrical boilers, 797 control systems, 646 , ' heaters, 794 conduction, 794 gravity convection, 795 '` radiant, 794 - heating, 793 auxiliary, 801 ' calculating capacities, 801 central fan, 796 control, 801 definitions, 793 domestic water, 799 < elements, 793 . power problems, 801 resistors, 794 ' hot water heating,'798 - . - panel beating, 807, 808 ,, ' precipitators, 568 radiant heating, QOS ' resistors, 793 unit heatera, 434,.795 _ Electricity, static, 728 Emissivity, 93 factors, 79 Enclosed radiator, 268 Enthalpy. 21, 845 free, 846 Entropy, 845 Equipment arrangement, 421 selection, 419 vibration, 641 , ': Equivalent evaporation, 845 Estimating fuel consumption. 227 ' Eupatheoscope, 815 Evaporative condensers. 491 cooled, unit conditioners, 445 cooling, 416, 458 Evaporators, 493 Excess air, 169 . -Exhaust opening, 590 * measurement of velocities, 676 Exhaust systems, 731 classification of, 731 corrosion protection,' 746 ducts for, 740 air velocities in, 741 ` construction, 741 design. 740 resistance. 742 efficiency of, 745 hoods. 731 air flow, 733 air velocities, 736 axial velocity formula for, 736 chemical laboratories,- 739 design principles, 732 kitchen, 739 large open. 738 lateral exhaust, 738. low velocity systems, 737 spray booths, 739 velocity contours, 736 resistance of, 744 suction requirements, 733 types of fans. 746 velocity requirements, 733 Expansion of pipe. 350 tanks, 315 valves, 488 F Fan, fans, 385, 575 - arrangement of drives. 586 attic, 441, 455 % economics, 455 \ r. location, 456 types, 456 axial flow, 575 booster, 382 centrifugal, 575 characteristic curves, 578 control, 587 designations. .587 efficiency. 577 furnace system, 391 motive power. 588 noise generated, 629 ? . performance, 576 radial flow, 575 selection of, 584 ...... air conditioning systems, 585 industrial exhaust systems, 746 system characteristics, 582 _ . .`Volume control, 588 Festoon dryer, 746 Fever therapy, 705 equipment for production of, 705,.-- ' Film conductance,-88 Filter, filters, 385 air conditioning units, 443 dry air, 568 ........... dust, 743 viscous automatic, 567 .viscous impingement type, 566 Fittings. 345 ' ' '"' pipe allowance. 292, 317, 823 types of, 354 ' - Flame. 167 'Flexible mountings, 641 . ... . Float trap, 285 Floor cooling unit, 453 -heat transfer coefficients, 115 \ unit heater, 426