Document g27KQebNjyyM9gRgG2dVjbLR3

HEATINC VENTILATING AIR CONDITIONING GUIDE 1943 Centimeter-gram-second (system) Change in specific volume during vaporization___ Cubic__________ Cubic foot.: Cubic feet per minute_____ ____ _________________ Cubic feet per second_______________ ____________ Decibel____..____________________________________ Degree* Degree centigrade_________ ______ ______________ Degree Fahrenheit Degree Kelvin____ .'.i____________________ Degree Reaumur Density, Weight per unit volume, Specific weight --.......... -cgs ------------------- t>fg _________ -CU _____ :--CU ft ______ --cfm _________.cfs _________ db ____deg or _________ C _____ F .!____ :___ K _________ R .d or p (rho) r Diameter_____ _____________ Direct-current (as adjective).. Distance, linear... .D or diam ----------- d-c Dry saturated vapor, Dry saturated gas at saturation pressure arid temperature, vapor in contact with liquid:_______________________ ^_________________ Subscript g Entropy. (The capital should be used for any weight, and the small letter for unit weight)---------- ;____________________________ !5or s Feet per minute____ ___ ____ ____________ _____ __ _________ __________ ._____ ___ :.fpm Feet per second_________________________ _____ _______________ ;_______ _____ ____ fps Foot.________________________________________ _____ !_______________________________ ft Foot-pound__________________________________ _________ ,............................................ ft-lb Foot-pound-second (systerri)___________________ .;fpa Force, total load_______________ ,________ ______ ,r:__________________________________ p Freezing point______________________________ _________ fp Gallon____________________________________________ _gal Gallons per minute-- Gallons per second_ Gram............ .............. Gram-calorie_______ Head- -------------gpm ----- --------gps -g -g-cal -H or A Heat content, Total heat, Enthalpy. (The capital should be used for any weight and the small letter for unit weight)....H or A Heat content of saturated liquid, Total heat of saturated liquid, Enthalpy of saturated liquid, sometimes called heat of the liquid.. Af Heat content of dry saturated vapor, Total heat of dry saturated vapor, Enthalpy of dry saturated vapor___________ ________ ____________________________ ...hs Heat of vaporization at constant pressure............................... ...................................L or Afg Horsepower..__________________________________________________________________ . h p Horsepower-hour. Hour:.--................ Inch____________ ,,hp-hr ....... hr Inch-pound....!_______ _____________________________ _________ ________________ .. in.-lb Indicated horsepower-..................................................... i............................................... ___ihp Indicated horsepower-hour.___________________________________ _ .ihp-hr Internal energy, Intrinsic energy. (The capital should be used for any weight and . the small letter for unit weight)_______ _____________________ __ ______ ; V or u Kilogram;_____________________________ ___ ______ __ 1......................................... ----- kg Kilowatt.___________ _________________________ ___ ________ _________ ________ .............kw Kilowatthour .......................................... .............................................................. ......... ...kwhr Length of path of heat flow, thickness....................... .................................................... ____ L Load, total______________________________________ ____________ _________________ W Mass;....................................................................................................................................; ...mass Mechanical efficiency............ .................................................... ;__;................................. ----- Cm Mechanical equivalent of heat______ ___________________________ ____ __j___ ____ J. Melting point,!.......................................................................... . ___mp Meter1- ________________________ ________________ m It U recommended that the abbreviation for the temperature scale, F, C. K. be included in expressions for numerical temperatures but. wherever feasible, the abbreviations for depce be omitted; as 68 F. 852 CHAPTER 48. ABBREVIATIONS, SYMBOLS, STANDARDS MicronMiles per hour.. . p. (mu) -----mph Millimeter.------ Minute.. Molecular weight----- MoL----------------------- Ounce.. Pound..... .. Power, Horsepower, Work per unit time.. ..mol. wt ____ mol ___ oz ...... lb ____ P Pressure, Absolute pressure, Gage pressure, Force per unit area--------------------------- Quantity (total) of fluid, water, gas, heat; Quantity by volume; Total quantity of heat transferred---------- . Quality of steam, Pounds of dry steam per pound of mixture.. Revolutions perminute.-- :__________ _____ rpm Saturated liquid at saturation pressure and temperature, Liquid in contact . with vapor._:!--------------------------- ---------- ----------------------------------------Subscript f Second,--.......................................................-............................................... ............................. sec Specific gravity...................................--.....--...........................-----------------------------------.sp gr Specific heat.................................................................................. ....................... ...........sp ht or c Specific heat at constant pressure.................................................................................... ............ -p Specific heat at constant volume---------------------------------------------------------------- --.....-cv Specific volume. Volume per unit weight; Volume per unit mass.. Square foot------------------------------------------------- --------------------------- -sq ft Square inch___ ..sq in. Temperature (ordinary) F or C. (Theta is used preferably only when t is used for Time in the same discussion)------------------------------------------------------------ 1 or 8 (theta) Temperature (absolute) F abs or K. (Capital theta is used preferably only when small theta is used for ordinary temperature)------------------- 1----- T or 0 (capital theta) Thermal conductance4 (heat transferred per unit time per degree)---- ------------------------- C C = = kA L <i - h Thermal conductance per unit area. Unit conductance (heat transferred per unit time per unit area per degree)----------------------------------------------------------- f-a AC, _ 1 RAa q A(ti - l,) k L -Thermal conductivity (heat transferred per unit time per unit area, and per degree per unit length)!.-._____________________________________ ____________ g k= A h) Surface coefficient of heat transfer, Film coefficient of heat transfer, Individual coefficient of heat transfer (heat transferred per unit time per unit area per degree):--------------------------------- :............................ :---------------------.................. ....... -/ g A / = 1,-1, (In general / is not equal to k/L, where L is the actual thickness of the fluid film.) Over-all coefficient of heat transfer, Thermal transmittance per unit area (heat transferred per unit time per unit area per degree over-all)..................... -...... U g A V = fi - t. <Terms ending ivity designate properties independent of size or shape, sometimes called specific properlies. Examples: conductivity, resistivity. Terms ending ance designate Quantities depending not only on the material, but also upon size and shape, sometimes called total Quantities. Examples: conductance, transmittance. Terms ending ion designate rate of heat transfer. Examples: conduction, transmission. 853