Document 7MnOXzEYrZj17dkMKYx257MVB

CHAPTER 32 1956 Guide 762 ** Air Conditioning of Multi-Room Buildings, by R. W. Waterfili (A.S.H.A.E. Tbansactions, Vol. 61, 1955, p. 233). / a Air Conditioning Multi-Story Buildings, by P. B. Gordon (Heating Piping and Air Conditioning, April 1955, p, 112. Discussed loc. cit. May 1955, p. 103). ,4 Standards of the National Board of Fire Underwriters (N.B.F.U. Pamphlet No. 90, p. 21). BIBLIOGRAPHY FLEUleIDmePnLtaOryWM{eSchrxaCnichsgvotftrF4lu)i.d. s, by Hunter Bouse, 1946. (John Wiley A Sons, Inc.). Engineering Applications of Fluid Mechanics, by 3. C. Hunsaker and B. 'G. Rightmire, 1947 (McGraw- HilFl BluoidokFCloowmipnaPniyp,eIsn,cb.)y. Clifford McClain, 1952. (The Industrial Press, New York). Plow and .Pan--Principles of Moving Air Through Ducts, by Harold C. Berry, 1254. (The Industrial PreTssh,eNeFwlowYoorfk)F. luids in Closed Conduits, by R. J. S. Pigott (Mechanical Engineering, Vol. 55, 1933, v .p.4A97)S. tudy - of the Data on the Flow of Fluids iu Pipes, by E. Kemler (ASMS Transactions, Vol. 55, 1933, Hydraulics, p. 7). . . PLOAW.S.OHP.VA.EI.RRIeNseaDrUcChTRSeport No. 1105--Frictional Resistance to the Flow of Air in Straight Ducts, by F. C. Houghten, J. B. Schznieler, J. A. Zalovcik, and N. Ivanovic (A.S.H.VJE. Transactions, Vol. 45,1939, P.3A5.)S.,.H..VJ3. Research Repost No. 1154--Analysis of Factors Affecting DuctFriction, by J. B. Schioieter F. C. Hougbten, and H, T. Olson (AJ5.H.V.E. Transactions, Vol. 46,1940, p. 193). : Pressure Loss Characteristics of Small Diameter Round Duct Systems, by G. R. WHtnah and J. V. Borry. (A.S.H.VJ2. Journal Section, Beating, Piping <fc Air Conditioning, November 1952, p. 111). . A.S.H.V.E. Research. Report No. 1470--Pressure Losses in 4-Inch Diameter Galvanised Metal Duct and Fittings/ by H; G. Conn, W. G: Colborne, and W. G. Brown. (A.S.H.V.E. Transactions, Vol. 59,1953, p. 130). . PRLEoSgsSUofRPEreLssOuSreSDIuNe tEoLEBlOboWwSs in the Transmission of Air Th.rough Pipes or Ducts, by Frank L, Busey (A.SN.eHw.VD.Ea.tTa rfoarntshaectDioensisg,nVoofl.E1lb9,o1w9s13i,npDp.u3c6t6S-3y7s6te).ms, by Loring Wirt (General Electric Review, Vol, 30. Jt u nAen10In27v,epspti.g2a3ti6o-n29o8)f. Pressure Losses in Air Duet-Elbows, by Oliver E. Parker (Northeastern Univer sit- yInthveessist,igMataioyn28o,f 1A0i3r4F). low in Right Angle Elbows in a Rectangular.Duct, by Charles H. McLellan and Walter A, Bartlett, Jr.. {National Advisory Committee for Aeronautics, Advanced Restricted'Report L-328, Oc t.Vo:bAer-,S1.H04.V1)J.B. Research Report No. 1211--Pressure Loss Caused by Elbows in Eigh_t--In-ch Round Venti lating Duct, by Mi C.. Stuart, C, F. Warner and W. C. Roberts (A.S.H.VJE. Transactions, Vol. 48, 1942. pp. 335-350). / . Experimental Investigation of Velocity Distributions Downstream of Single Duct Bends, by John K. .Weske {National 'Advisory Committee.forAcronavtics.Technical Note 1471, January, 1948); Investigations oif the Flow in Curved Ducts at Large Reynolds Numbers, by John R. Weske (Journal o:f.AHpopwlieMduMcehcPharensicssu,reDLeocessmibne.rR, o19u4n8d, pEplb. o3w44s-?3,4b8y).. R: K. Guthrie (Heating; Piping ,<.rfc Air Conditioning, March 1055, p. 130'and discussions by R. D. Madison and R. M. Conner, April 1955, p. 89, and by the author, June 1655, p. 81>. '"P*R` AE.SSS.HUiRVE.EL. ORSeSseIaNrcDh IRVeIDpoErDt-NPoL.O1W392--FIFTiTttIiNngGLSosses for Extended-Plenum Forced Air Systems, by H. H. Korst, H. A. Buckley, S. Koazo, and R. W. Rouse. {A.S.H.V.E. Transactions, Vol. 56, 1950, ,p. 259). A.S.H.V.E. Research Report No. H30--Pressure Losses of Take-Offs for Extended-Plenum Duct Sys tems, by J. W. Holt, S. F. Gilman, R. J. Martin, and S. Konto. (A.S.H.V.E, Transactions, Vol. 57, 1951. p- 419).. D UAC,TS.HD.EVS;EIG. RNesearch R e. port No. 1050--A Rational Me.tho.d of.Duct Design, by L. G. Miller. (AB H.VM.Eo.dTerrnaTnhsaincktiinognsA, pVpolil.e4d3t,1o9D37u, cpt. D71e)s. ign, by Kirby Walker, (Heating, Piping it Air Conditioning March 1949, p. 85; April 1949, p. 104; May 1949: p. 91; July 1949, p. 95: September 1949, p. 96; November 1949, p. 9P7;oiMntaerrcsho1n0A50i,rpC:o9n?daitniodnMinagyD1u95c0t,Dpe. s9i4g)n. and Installation (Heating andVeTtlilating's Reference Section, HeaEticnognaonmdicVael DntuilcattiLnagy, oOuctsto,bbeyr;P1e9t5e1r)F..ranck (Heating, Piping db`A > Conditioning, Dec'ember 1952, p. 1WW.The Design of Aluminum Duct Systems, by F. W. Hutchinson, 1054 (Kaiser Aluminum A Chemical Sales. IMncIS.P,CeOrEfaoLkrLmlaAanNndc,EeCOTaUel.s)S.ts of Asbestos Insulating ........... Air Ducts, by R. H1 .: Heilman and R. A. McArthur (AJS.H.V.E. Transactions, Vol. 44, 1938, p. 187),, !. CHAPTER 33 FANS Types, Fan Performance, Fan Laws, Fan Performance Curves, System' Characteristics, Fan Arrangements, Fan Control, Motive Power, Fan Selection, Fan Installation, Fan Applications IN HEATING, ventilating and air conditioning practice, the devices used to produce air flow are variously known as fans, blowers, exhausters or propellers. The A .S.M.E. Test Code1 limits fans to those in which the fluid density change does not exceed 7 percent (one psi at atmospheric pressure) and labels as compressors those devices operating beyond that pressure range. Since air conditioning rarely requires pressures of over $ psi, all such devices will be known as fans and the air will be considered non-compressible. Types Fans are divided into two general classifications: (1) centrifugal or radial flow in which the air flows radially through the impeller within a scroll type housing, and (2) axial flow in which the air flows axially through the impeller within a cylinder or ring. Centrifugal fans are further subdivided into types denoted by the curva ture or slope of the impeller blades, the angle of which largely determines the operating characteristics. For a given output, a forward inclination of blade indicates a relatively low speed of operation, and a backward in clination, a relatively high speed of operation. Many intermediate forms are also found. ArioZ flow fans are subdivided into types differentiated mainly by their enclosures and refinements of impellers and appurtenances. All types vary in shape, number and angles of blades; ratios of hub diameter to im peller diameter; materials and methods of fabrication, depending upon de sign and preference of manufacturer. Tubeaxial and vaneaxial fans; usu ally used against appreciable resistance, commonly have relatively large hubs and helical blades (the angle varies radially along the blade). The blades may be of uniform thickness, either flat or cambered, and either cast or made of plates; or they may be of air foil sections, either cast or of double thickness sheet. Streamlining of both impeller and enclosure is common practice. Vaneaxial fans incorporate guide vanes to modify per formance and increase efficiency. Propeller fans customarily used for free delivery, or against low resistance, also are found with a variety of blade conformations, but are simple in construction. They are merely mounted within a plate or ring. The fan nomenclature in Fig. 1 has been standardized by the National Association of Fan Manufacturers,2 FAN PERFORMANCE Fan performance is a statement of volume, total pressures, static pres ses, speed, power input, mechanical and static efficiency, at a' stated density. These terms are defined by the National Association of Fan Manufacturers2 as follows: . J- Volume bandied by a fan is the number of cubic feet of air per minute expressed * *an outlet conditions. 763