Document nmv4RpQjq80RbgBKeOOY7zg6w

.Heating. Ventilating - Air Conditioning Guide. 1953 Window, windows coefficients of transmission. , . 107 leakage, 219 solar radiation through, 285 ventilators, 587 Winter. ' - air conditioning system, 647 comfort rone, 124 freeling equipment, 782 Wound rotor motor, 879 Wrought-iron pipe; 603 Wrought^steel pipe, 603 Y Year-round air conditioning - system, 647 i air flow in, 647 control methods, 649 design procedure, 660 equipment arrangement, 648 7' installation, 648 location of apparatus, 659 selection, 657 .x Z: ":- Zone control, 648 Z:onensof evaporative regulation, Zoning, 538, 648 control, 648, 860 recooling, 631 - reheat, 648 volume control, 649 XXIV "s I I r> f : :1> 'I f I t 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, i.e.y 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), a = 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) (see) or 32.174 ft per (sec) (sec) which is tne actual value of this acceleration at sea level and about 45 deg latitude. Adiabatic: An adjective descriptive of a process such that no beat 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 liquids, 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, distri bution, 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 10-8 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