Document R21XYyZz1d7D0V5JZ9jGraD9X

716 CHAPTER 39 1946 Guide Vol. 105, p. 1161-1162, December 27..1929. and 1. E. E.-Journal. VoL68, p. 666-675, June, 1930). Edison Building Heated and Cooled by.Electricity, by H. L. Doolittle (Power. Vol. 74, p. 384. September 8,1931). House Heatmg by Pump with 5 to 1 Pick-up Ratio, by Gilbert Wilkes and R. E. Marbury (Electrical World p* 828'. December 17, 1932). An All Electric Heating, Cooling and Air Conditioning System, by PhiUp Spom and D. W. McLenegan (A.S.H.V.E. Transactions, Vol. 41,1935, p. 307). Using the Reversed ^ycle Refrigerating Principle for a Self-Contained Heating and Cooling Unit, by Henry-L. Galson (A.S.H.V.E. Journal Section, Heating, Piping and Air Conditioning, October, 1935, p. 497); Heating by Reversed Refrigeration, by A. J. Lawless (Heating, Piping and Air Conditioning, August, p. 473, September p. 519, 1940). , BIBLIOGRAPHY Refrigerating Data Book, Vol. 1 (American Society of Refrigerating Engineers). Refrigeration Engineering, by H. J. Macintire (John Wiley & Sons). Theory of Mechanical Refrigeration, by N. R. Sparks (McGraw-Hill Book Co., Inc.). Refrigeration and Air Conditioning Engineering, by B. F. Raber and F. W. Hutchin son (John Wiley & Sons). ; Refrigeration, by J. A. Moyer and R. U. Fittz (McGraw-Hill Book Co., Inc.). CHAPTER 40 _$ir ^t)iitriLution Standards for Satisfactory Conditions, Definitions, Mechanics of Air Distribution, Types of Supply and Return Openings, Outlet Locations, Return and Exhaust Intakes; Specific Ap plications, Balancing the System CORRECT air distribution contributes as much or more to the success of a forced air heating, ventilating, cooling or air conditioning system as does any other single, factor. An air conditioning system may deliver the required quantity of conditioned air and still fail to give satisfactory room conditions because of poor air distribution. The scope of the chapter is limited to the air distribution within the conditioned space. Reference is made to the distributing duct system only insofar as it affects the performance of the air distribution outlet. See Chapter 41 for informa tion on air duct design. STANDARDS FOR SATISFACTORY CONDITIONS Air distribution within a space to, be conditioned consists in producing within the space the proper effective temperature whether for cooling, heating or ventilating. This means that a reasonable uniformity of tem perature, humidity _and velocity must be obtained within the zone of occupancy. This zone is'usually the room space between the floor and a plane 6 ft above the floor. Air must have a proper combination of quan tity, temperature, humidity and velocity to satisfy the over-all demands, whether for cooling, heating or ventilating. Any or all of these factors may need to be controlled to produce proper comfort .conditions. Also the quantities delivered to various locations must be proportioned, so that the sections of the area having the highest or lowest load requirements are satisfied. Otherwise some areas will be too hot, cold, stuffy or drafty, since the effective temperature will be too high or low in these areas. Other important considerations are dirt and noise.. The use of air cleaning devices is recommended to prevent or reduce streaking and smudging of walls and ceilings. Outlets should not increase the noise above the acceptable level. Reference should be made to Chapter 12, Physiological Principles, for the accepted standards on room temperature, humidity, air motion and direction. Material in Chapter 42, Sound Control, covers acceptable room noise levels and noise generated by air outlets. DEFINITIONS The following ^definitions referring to air distribution equipment have gained general acceptance. 1. Supply Opening or Outlet:. .Any opening through which air is delivered into a space which is being heated, or cooled, or humidified, or dehumidified, or ventilated. 2. Exhaust Opening or Return Intake: Any opening through which air is removed from a space which is being heated, or cooled, or humidified, or dehumidified, or venti lated. 3. Outside Air Opening: Any opening used as an entry for air from outdoors. 4. Grille: A covering for any opening and through which air passes. 5. Damper: A device used'to vary the volume of air passing through a confined cross-section by varying the cross-sectional area. ' 6. Multiple Louver Damper: A damper having a number of adjustable blades. 717