Document pB07nOmpqoQYYwp7OmYnwOV5j

Heating Ventilation (.continued) rules, 146 ship. 666 symbols for drawings, 9 tanks, 709 walls, 137 wind forces, 139 Ventilator, ventilators, 145 control, 146 roof, 145 unit, 213 control, 215 Vertical blow unit heater, 218 Vertical openings, 143, 145 sealing of, 143 Vibration, machine, 352 Viscous filters, 324 impingement, 324 Vitiation of air, 61 Volume control, 278 furnace, 487, 490 specific, 6 W Wall, walls heat flow through, 102-109, 178, 195 heat transfer coefficients, 47, 102-109 infiltration through, 139 time lag of solar radiation, 191 Warm air gravity heating system, 6, 258 mechanical (forced) systems, 237 air distribution, 237 automatic control, 253, 625 ceiling panel system, 254 cooling methods. 651 continuous circulation, 253 dampen, 239 design procedure, 240, 250 ducts, 239 fans, 509 filtem, 509 furaaoe, 509 heavy duty, 510 selection, 253 humidification, 512 large systems, 250 perimeter system, 240-247 pressure drop, 257 panel heating, 254 registers and grilles, 237 Ventilating Air Conditioning Washer, washers, 592 air, 1, 592-594 cooling, 594 dehumidification,' 594 humidification, 594 Water analysis, 734 atmospheric cooling equipment, 579-581 characteristics,- 733 classification, 733 coils, 314, 758 content of radiators, 404 control temperature service, 760 cooled condenser, 556 cooling tower, 581 corrosion treatment, 735-743 demand, 748, 753-755 faucets, 747 fittings, loss, 752, 753 fixtures, 748 fixture units, 748 formed deposits, 733 heater coal-fired, 755 electric, 756 indirect, 757 solar, 760 heating, 753, 755 in building material, 128 load, 747 make-up, 688, 738 maximum main temperature, 595 meters, 752 mineralised, 734 properties of, 22, 734 services, 747 storage capacity, 753 supply piping, 760 arrangement, 758 temperature control, 759 thermodynamic properties of, 22 treating chemicals, 733, 744 well temperatures, 596 * Water vapor, 13, 18-21. 127 condensation in buildings, 127 saturation pressure, 13, 22 specific enthalpy, 2 specific volume, 6, 22 surface condensation, 132 Weather conditions design outdoor, 151, 168 Guide 1959 Welding, 443 * ^iure) sTmJwT Wet cup, 130 Wet return, 5, 355 Wind, winds forces, 139, 143 due to stack effect/139. natural draft equipment, 515 selection of, velocity, 152, 170 Window, windows coefficients of transmission, 123 . leakage, 140 solar radiation through, 184 Winter air conditioning system, 259, 651 comfort chart, 67,. 70 freezing equipment, 589 Wound rotor motor, 641 Wrought-iron pipe, 435 Wrought-5teel pipe, 435 Y Year-roand air-conditioning system, 259, 651 air flow in, 261, 654 control methods, 260, 619-623, 625 design procedure, 259, 265, 651 equipment arrangement, 266 installation, 259, 651 location of apparatus, 266, 653 residential, 977 selection, 265, 651 Z Zero, absolute, 1 Zone, zones control, 260, 618, 623, 624 evaporative regulation, 63 metabolic regulation, 63 thermal neutrality, 67 vaso-motor regulation, 63 Zoning, 260, 618, 623 , control, 260, 618, 623 hot water system, 623 reheat, 280 volume control, 260 XXiv CHAPTER TERMINOLOGY Glossary of Physical and Heating, Ventilating, Refrigerating and Air Conditioning Terms Used in the Text Absolute Zero: The sero from which absolute temperature is reckoned. Approximately --273.15 C or --459.67 F. These values were established by the Tenth General Conference on Weights and Measures (1954). Absorbent: A sorbent which changes physically or chemi cally, 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, i.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 fps system the unit is the foot per (second) (second), do 0 = df Acceleration Dae 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) which 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 under going 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 extracting one or more substances preseot in an atmosphere or mixture of gases and liquids, unaccompanied by physical or chemical change. Commercial adsorbent ma terials 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, ana smokes. (Air cleaners include air washers, air filters, electrostatic precipitators, and charcoal filters.) Air Conditioning: The process of treating air so as to con trol simultaneously its temperature, humidity, cleanliness, and distribution to meet the requirements of the conditioned space. 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 0.0379 X 10~f lb mass per (ft) (sec). This is substantially equivalent to dry air at 70 F and 29.92 in. Hg barometric pressure. Air Washer: An enclosure in which air is drawn or forced through a spray of water in order to cleanse, humidify, or dehumidify tne 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 of the atmosphere to be measured by means of the barometer. Standard Atmospheric Pressure or Standard Atmosphere is exactly 1,013,250 dynes per 8a cm by recent action of the Tenth General Conference on Weights and Measures (1954). It is approximately the pres sure exerted by a column of mercury 76 cm high at standard gravitational acceleration, 980.665 cm per (sec) (sec), the mercury having a density of 13.5951 g per cu cm. It is equiva lent to 14.696 psi or 29.921 in. Hg at 32 F. Baffle: A surface used for deflecting fluids, usually in the form of a plate or wall. Blast Heater: A set of heat transfer coils or sections used to heat air which is drawn or forced through it by a fan. Blow (throw): In air distribution, the distance an air stream travels from an outlet to a position at which air motion along the axis reduces to a velocity of 50 fpm. For unit heaters, the distance an air stream travels from a heater without a perceptible rise due to temperature difference and loss of velocity. Boiler Heating Surface: All of the surface of the heat-trans fer apparatus in contact on one side with the water or wet steam being heated and on the other side with the gas or re fractory being cooled, in which the fluid being heated forms part of the circulating system, this surface to be measured on the side receiving heat. (Stationary Steam-Generating Unite, ASMS Pouter Test Codes, PTC 4-1946.) Direct Heating Surface is generally understood to be the boiler heating surface subject to direct radiation from the sur face of the grate, or from the surfaces of oil or gas burners. Indirect Healing Surface is' the boiler heating surface within the flues. Boiler Horsepower: The equivalent evaporation of 34.5 lb of water per hr from and at 212 F. This is equal to a heat out put of 970.3 X 34:5 = 33,475 Btuh. British Thermal Unit (Btu): The Btu is defined as 778.177 foot-pounds if it is related to the IT calorie in such a way that 1 IT caloric per (kg) (C deg), -- 1 Btuj>er (lb) (Fdeg), with 1, lb = 453.5W4 g. The Ninth General Conference on Weights and Measures (1948) recommended the absolute joule as the fundamental unit of energy thereby, in effect, liquidating the old international electrical units. This calls for a redefinition of the International Tables calorie (IT cal) according to the following conversion factor: 4.18684 joule per IT calorie. Calorie (Gram Calorie): The IT gram calorie is equivalent to 0.003968 Btu. (See definition of Btu.) Central Fan System: A mechanical indirect system of heat ing, ventilating, or air conditioning, in which the air is treated or handled by equipment located outside the rooms served, usually at a central location, and is conveyed to and from the rooms by means of a fan and a system of distributing ducts. (See Chapter 19.) s' Chimney Effect: The tendency of air or gas in a duct or other vertical passage to rise when heated due to its lower density compared with that of the surrounding air or gas. In buildings, the tendency toward displacement (caused by the difference in temperature) of internal heated air by unheated outside air due to the difference in density of outside and inside air. ' Coefficient of Performance (Heating): The ratio of the total instantaneous useful heating effect produced by a heat pump system at stated conditions, to the heat equivalent of the total energy input rate required to drive or operate the system. Coefficient of Performance (Cooling): The ratio of the instantaneous refrigeration effect produced by a heat pump 1