Document Vj91gLz227YwYao3YDYk1XJv4

Heating Ventilating Air Conditioning Guide 1950 Ventilator, ventilators, 217 - control, 218 roof, 217 unit, 540, 812 control, 812 window, 544 Vertical blow unit heater, 533 Vertical openings, 211 sealing of, 211 Vibration machine, 861 Viscous filters, 694 automatic, 695 impingement, 694 Vitiation of air, 115 Volume control, 635 . furnace, 336, 343 --'specific, 10 W Wall, walls heat flow through, 179, 239. 265, 270 heat transfer coefficients, 101, 169, 179 infiltration through, 205 ' time lag of solar radiation, 265 Warm air . gravity heating system, 415 combination carrying capac ity, 421 design procedure, 422 furnace capacity, 369 installation practice, 415 standardised combinations, 418 mechanical heating 'systems, 425 automatic control, 369, 429 cooling methods, 439 continuous circulation, 439 dampers, 427 design procedure, 428 ducts, 427 fans, 368, 439 ' filters, 368 furnace, 367 heav^ duty, 368 selection, 439 humidification, 373 Warm air (continued) mechanical (continued) Ur$e systems, 429 registers and grilles, 426 standard combinations, 427, 428 panel heating, 518 radiant heating, 518 radiators, 346 Washer, washers, 709 air, 1, 709 . Water analysis, 874 atmospheric cooling- equip ment, 709, 719 characteristics, 874 classification, 874 coils, 735, 989 . control temperature service 994 coded condenser, 781 corrosion treatment, 873 demand, 977 faucets, 978, 983 fittings, loss, 985 fixtures, 978 fixture units, 978* formed deposits, 873 heater coal-fired, 989 soiar,995 heating, 868, 988 load, 986 make-up 733 maximum, main temperature, 712 - meters, 983, 984 mineralized, 874 properties of, 36 supply piping, 977, 978, 986, 993 arrangement, 993 services, 977 storage capacity, 986 supply, 977 temperature control, 994 thermodynamic properties of, 36 treating chemicals, 873, 691 well temperatures, 714 Water (continued) Water vapor, 24, 36, 197 saturation pressure, 36 specific enthalpy, 4 specific volume, 10,36 surface condensation, 198 Welding, 557 Wet-bulb temperature (see Tem perature), 9, 725 Wet return, 8, 443 Wind, winds forces, 205 due to stack effect, 205 natural draft equipment, 719 selection of, velocity, 226, 252 Window, windows coefficients of transmission. 196 leakage, 207 solar radiation through, 277 . ventilators, 544 Winter air conditioning system, 601 comfort zone, 130 freezing, equipment, 732 Wound rotor motor, 833 Wrought-iron pipe, 557 Wrought-eteel pipe, 557 Y Year-round air conditioning sys tem, 601 z Zone control, 602 Zone of evaporative regulation, 119 Zoning, 602 control, 602, 810 recooling, 603 reheat, 603 volume control, 635 XXIV CHAPTER 1 TERMINOLOGY Glossary of Physical and Heating, Ventilating, Refrigerating and Air Conditioning Terms Used in the Text Absolute Zero: The zero from which absolute temperature is reckoned. Ap proximately --273.2 C or --459.8 F. Absorbent: A sorbent which changes physically or chemically, or both, during the sorption process. Absorption: The action of a material in extracting one or more substances present, in an atmosphere or mixture of gases or liquids; accompanied by physical change chemical change, or both, of the sorbent. Acceleration: The time rate of change of velocity, t.e., the derivative of velocity with respect to time. In the cgs system the unit of.acceleration is the centimeter per (second) (second); in the fpB system the unit is the foot per (seoond) (second), o = do . Acceleration Due to Gravity: The rate of gain in velocity of a freely falling_body, the value of which varies with latitude and elevation. The international gravity standard has the value of 980.665 cm per (sec) (sec) or 32.174 ft per (sec) (sec) winch is the actual value of this acceleration at sea level and about 45 deg latitude. Adiabatic: An adjective descriptive of a process such that no heat is added to, or taken from, a substance or system undergoing the process. Adsorbent: A sorbent which does not change physically or chemically during the sorption process. Adsorption: The action, associated with surface adherence, of a material in ex tracting one or more substances present in an atmosphere or mixture of gases and liquid , unaccompanied by physical or chemical change. Commercial adsorbent materials have enormous internal surfaces. Aerosol: An assemblage of small particles, solid or liquid, suspended in air. The diameters of the particles may vary from 100 microns down to 0.01 micron or less, e.g., dust, fog, smoke. Air Cleaner: A device designed for the purpose' of removing airborne impurities such as dusts, gases, vapors, fumes and smokes. (Air cleaners include air washers, air filters, electrostatic precipitators and charcoal filters.) Air Conditioning: The simultaneous control of all, or at least the first three, of those factors affecting both the physical and chemical conditions of the atmosphere within any structure. These factors include temperature, humidity, motion, distribution, dust, bacteria, odors and toxic gases, most of which affect in greater or lesser degree human health or comfort: (See Comfort Air Conditioning.) . Air, Dry: In psychrometry, air unmixed with, or containing no, water vapor. . Air, Saturated: A mixture of dry air and saturated water vapor, all at the same dry-bulb temperature. Air, Standard: Air with a density of 0.075 lb per cu ft and an absolute viscosity of 1.22 X 10"s lb mass per (ft).(sec). This is substantially equivalent to dry air at 70 F and 29.92 in. (Hg) barometer. Air Washer: An enclosure in which air is drawn or forced through a spray of water in order to cleanse, humidify, or dehumidify the air. . Anemometer: An instrument for measuring the velocity of a fluid. Aspect Ratio: In air distribution outlets, the ratio of the length of the core of a grille, face or register to the width. ' In rectangular ducts, the ratio of the width to the depth. Atmospheric Pressure: The pressure due to the weight of the atmosphere. . It is the pressure indicated by a barometer. Standard Atmospheric Pressure or Standard Atmosphere is the pressure of 76 cm of mercury having a density of 13.5951 grams per cu cm, under standard gravity of 980.665 cm per (sec) (sec). It is equivalent to 14.696 lb psi or 29.921 in. of mercury at 32 F. -Baffle: A surface used for deflecting fluids, usually in the' form of a plate or wall. 1