Document qa01ra6MDVLdz9ZXKjp66mQmR

American Society of Heating and Ventilating Engineers Guide, 1937 Ventilation (continued) natural, 79 advantages of, 79 air changes per hour, 137 control of, 89 disadvantages of, 79 general rules for, 93 heat to be removed by, 91 requirements for, 79 openings, doors, 87 ^ formula to determine size of, 85 location of, 91 skylights, 87 types of, 86 windows, 87 * for public buildings, 371 . purpose of, 91 Quantity of air necessary for, 74, 543 ' railway air conditioning, 399 by registers, 89 for schools, 74 . by stacks, 89 standards, 81, 807 symbols, 804 Ventilator, ventilators, resistance of, 88 roof, 88. 795 unit, 235, (see also Unit Ventilators) Venturi chimney, 464 Vitiation of air, 55 Volume, of air and saturated vapor, 12 conversion equations, 801 furnace, 792 specific, 3 of saturated steam, 28 of water, 27 W Wall, walls, air leakage through, 132 of chimneys, 479 fire. 391 ' heat transmission coefficients for. 99: 100, 107. 114, 116, 118 radiators, output, 534 solar radiation on, 160, 161 time lag through, 162 Warm air heating systems, 798 gas-fired furnaces for, 514 gravity, 411 mechanical, 427 Washers, air, 217, 430, 788 capacity of, 220 types of, 217 Water, 38 boiling point of, 27 circulating, temperature of, 224, 679 from city mains. 196, 209 ^ cooling, equipment, 223 quantity, 193, 224 * temperature, 224 composition of, 27 density of, 27 domestic supply, 645 evaporation of, 232 factor of usage, 647 flow from fixtures, 646 freezing, 679 friction losses through pipes, 653 hammer, 573 heaters, 171, 661 heating, 645 hot, domestic supply, 659. 661 boilers, 445 demand for, 665 electric heating of, 720 Water (continued) hot, domestic supply pipe sizes for, 656 storage of, 664 heating systems, 601, (see also Hot Water Heat ing Systems) inches of water, 793 line, in boilers, 458, 459, 545 in water supply systems, 652 make-up, 232 meters, disc, 651 pans, for humidification, 538 pressures, 27 properties of, 27 replacement of, 232 supply piping, 645 temperature, maximum main, 196 thermal properties of, 27 vapor, 5, 10, 12 given off in combustion of gas. 493 heat content, 12, 23 mean specific heat of, 3 weight of saturated, 12 Weather Bureau records, temperature, 148, 158 wind, 148, 158 Weatherstripping, 136 Weight, of air, 6 conversion equations, 801 of steam, 28 of vapor, 12 of water, 27 Welding, 623, 634 neck flanges, 639, 640 Wet-bulb temperature (see Temperature, Wet-bulb) Wet return, 798 Wind. in cities, 148, 158 effect on heating requirements, 147 forces in natural ventilation, 85, 91, 131 ' . . prevailing, direction of, 137, 158 records of velocity and direction, 148, 158 velocity on natural draft equipment, 230 average. 85, 137, 147, 158 equivalent, in tall buildings,* 138 used in calculations, 137 Window, windows, 87, 89 - air leakage through, 136 clearance of sash, 134 coefficients of transmission of, 127 comparison of various shades for, 163 crack, 134 measurement of. .134 solar radiation through, 163 storm sash, 135 Winter, comfort zone, 67, 68 , conditioning, apparatus for, 186 cooling in, 157 humidification in, 187, 538 relative humidity in, 69, 72 temperatures, 148 wind velocities and directions, 148 Wood, woods, air speed for conveying, 392 heat transmission coefficients of, 112 Z Zero, absolute, 787 Zone, zoning, for air conditioning systems, 188. automatic control, 280 comfort, 67, 68, 70, 789 average, 68 extreme, 68 - control of steam heating systems, 560 for cooling of buildings, 164 for large heating systems, 619 neutral, 795 water supply systems, 645 rt \A Ameri can Society of Heating and Ventilating Engineers U Vol. 15 1937 Chapter 1 AIR, WATER AND STEAM Dalton's Late, Temperatures, Air Properties, Humidity, Relative Humidity, Specific Humidity, Relation of Detc Point to Relative Humidity, Adiabatic Saturation of Air, Total Heat and. Heat Content, Enthalpy, Psychrometric Chart, Properties of Water, Properties of Steam, Rate of Evaporation AIR conditioning has for its objective the supplying and maintaining, in a room or other enclosure, of an atmosphere having a composition, temperature, humidity, and motion which will produce desired effects upon the occupants of the room or upon materials stored or handled in it. Dry air is a mechanical mixture of gases composed, in percentage of volume, as follows1: nitrogen 78.03, oxygen 20.99, argon 0.94, carbon dioxide 0.03, and small amounts of hydrogen and other gases. Atmospheric air at sea level is given in percentage by volume as: N2 77.08, Oj 20.75, water vapor 1.2, A 0.93, COj 0.03 and H2 0.01. The amount of water vapor varies greatly under different conditions and is frequently one of the most important constituents since it affects bodily comfort'and greatly affects all kinds of hygroscopic materials. DALTON'S LAW A mixture of dry gases and water vapor, such as atmospheric air, obeys Dalton's Law of Partial Pressures; each gas or vapor in a mixture, at a given temperature, contributes to the observed pressure the same amount that it would have exerted by itself at the same-temperature had no other gas or vapor been-present. If p = the observed pressure of the mixture 'International Critical Tables. I