66 CHAPTER 3 1956 Guide LETTER SYMBOLS (Concluded) t>*i " v, -- o, the difference between volume of moist air at saturation, per pound of dry air, and the volume of the dry air itself, cubic feet per pound of dry vt = volume of moist air at saturation per pound of dry air, cubic feet per pound of dry air,; vi = total volume, cubic feet.

412 CHAPTER 16 1956 Guide FURNACE RATING Rating Equations for Gravity Warm Air Furnaces10 Until a method of testing and rating gravity warm air furnaces has been developed, the following empirical rating equations are recommended by the National Warm Air Heating and Air Conditioning Association.

680 CHAPTER 29 1956 Guide Typical service connections are shown in Fig. 2 for low-pressure service and Fig. 3 for high-pressure service.

786 CHAPTER 34 1956 Guide therefore, care must be exercised in arranging the duct approaches on the entering and leaving sides of the cleaners in order that the air flow may be distributed uniformly over the cross-sectional area.

832 CHAPTER 36 1956 Guide loads, is also minimized.

1082 CHAPTER 47 1956 Guide Industrial Drying Systems Cxmaust 1083- classified as a convection dryer the principal squrce of heat is the heated air or- other gases circulated in the dryer.

1170 CHAPTER 53 1956 Guide Table 1.

\i f / ia 48 CHAPTER 3 1957 Guide Sife Noonooo>o9oo<o0o foooi*oo*5oo^s co ooCoe-s o0O SoOrnOCaboOo^ CoC**eo>**3oC^>oCO*eotf>* rC-GjMO &ONl*OM"--NNC* Sat.

154 CHAPTER 8 1957 Guide v particles in the 0.1 micron vicinity may have influenced the determination . ' of average particle size.

434 CHAPTER 17 1957 Guide FACTORS AFFECTING NATURAL DRAFT As indicated in both Equations 1 and 2, the theoretical natural draft is directly proportional to the height of the flue and is dependent upon the absolute mean temperature of the gases within the-flue.

454 CHAPTER 17 1957 Guide of the National Board of Fire Underwriters for the Installation of Heat Producing Appliances, Heating, Ventilating, Air Conditioning, Blower and Exhaust Systems. 2.

568 CHAPTER 21 1957 Guide pumps is established by adding the flow capacity of one pump to the flow capacity of the other at identical heads.

710 CHAPTER 27 1957 Guide third inches would be averaged and the pipe size for list price would be that nearest the average pipe size of the second and third inch.

1236 CHAPTER 52 1957 Guide eral instruments have been devised to evaluate the comfort or warmth of rooms, taking radiant as well as convective effects into account.

Heating Ventilating Air Conditioning Guide 1958 Tables (ctmiinued) humidities, industrial air con ditioning, 1142-1152 hygroscopic rrmtorinlfi H54 incident angle, 299 inertial separator, 859 infiltration through outside doors, 244 - infiltration through walls, 240 infiltration through windows. 242 inflammability, gases. 164. 165 inside temperatures, 271, 291. 1142-1152 instantaneous solar heat gain 312, 313, 315-320 insulation conductivity, 704 insulation factors, 712 insulation thickness, 716, 723 insulation to prevent freezing. 720. insulation, underground, 723 intake velocity, 784 iron elbow equivalents, 564 life of equipment, 1094 limits for contaminants, 164 load factors, 482 maintenance cost, 1096 maximum allowable concen trations dust, fumes, mists, 158-161 dusts, 161, 162 flammable gases, 158, 164. 165 gases, 158-161 vapors, 158-161 metal gages for ducts, 817,1134 meter performance, 1204 minimum outdoor air require_ ments to remove odors, 113 moist air factors, 28 moisture content for mate rials, 1154 moisture regain, 1154 moisture transfer, 225 motor classification, 996 motor current, 997 motor design Limits, 994 motor drive applications, 1001 motor horsepower, 994 motor ratings, 1003 motor speed range, 994 motor starting methods, 1004 motor torque, 1001 motor voltage, 994 noise levels, 1021 octave frequency bands, 1012 oil fuel specifications, 356 oil heat value, 357 operating cost, 1092, 1094. 1095 operating hours, 1097, 1228 orifice capacities, 525 outdoor air requirement. 113. 297 outlet velocities, 838 outside temperatures, 263, 291 owning and operating cost. 1092, 1095 panel resistance ceiling, 620, 623 floor, 627 floor covering, 628 particle size, 153, 154 particulate matter, size, 153 perimeter extended plenum branch duct capacity, 494 size, 497 perimeter loop system diffuser area, 489 duct capacity, 492 feeder diameter, 488 perimeter radial system feeder duct capacity, 491 perimeter system return duct capacity, 498 permeability to vapor, 225 physiological response to heat 117 pipe application, 700 pipe capacity, 403, 409, 527, Tables (continued) 528, 530, 532-535, 537, 561. 948, 949 pipe correction factor, 641 pipe covering factors, 712 pipe dimension, 674 pipe fittingB, 680 dimensions, 682-693 pressure ratings, 681 pipe insulation, 704 pipe roughness, 73, 796 pipe surface, 674 thermal stress, 695, 696, 698 pipe volume, 579, 674 pressure loss area change, 801 ducts, 510 elbows, 529, 564, 800, 1204 ' fittings, 488, 502, 529. 564. 1204 refrigerant line, 948, 949 registers, 508, 509. return intake, 784 velocity, 803 properties of air, 32-39 dichlorodifluoromethane 915 fuel oil, 356 gaseous fuels, 364 moist air, 32-39 monochlorodifluorometh ane. 917 monofluorotrichloromethane, 918 steam. 49 trichlorotrifluoromethane. 918 water, 40-48, 593 radiation, black body, 96 radiation factors, 95, 603 radiation problem solution, 97 radiator beat loss correction factors, 602 raffiator sizes, 596-598 rating air conditioning units 667 rating steel boilers, 419, 420 ratio of specific heats, 73 refrigerant properties, 915, 917. 918 refrigerant line capacity. 948, 949 refrigeration equipment selec tion, 952 regain of hygroscopic mate rials, 1154 register pressure loss, 508, 509 register temperature, 506, 507 requirements for fuel oil, 356 resistor beat output, 1063 return pipe capacities, 528. 532, 533, 535 room temperature differential. 272 saturated steam, 49 screen mesh, 154 shading effect, 321 sheet metal gages for ducts, , 817, 1134 ship design conditions, 1193 skylights, 212 slime control, 1077 slime formers, 1068 smoke chart numbers, 1257 snowfall data, 633 snow melting systems, 637 sodium dichromate, 1081 soil conductivity, 173 sol-air temperature, 302 solar altitude, 298-300 solar azimuth, 300 solar declination, 300 solar heater design, 1219 solar heat gain, 304, 312-321 solar radiation, 298 sound attenuation, 1027, 1028, 1030, 1031 sound level, 1018. 1021, 1039 specific gravity factors, 410 specific heat of compressible fluids, 73 Tables (continued) specific heat ratio, 73 spray pond design data, 877 steady-state conduction prob lems, 101 steam consumption buildings, 479, 728 > equipment, 726 r water heating, 727 steam conversion factors,' 602 steam pipe capacities, 527.530 532-535 steam pressure, 49 steel boiler ratings, 419. 420 summer' climatic conditions . 291 summer design condi tiona. 288, 291 surface conductance,. 93. 174. 178 temperature, bonnet, 506, 507 temperature differential, 272. 304, 306, 307 .