Document LJ1vVyZwZVDmvkrLZDoEV5N2w

HEATING VENTILATING AIR CONDITIONING CUIDE 1944 Centimeter-gram-second (system)_____ . T___ !:cgs Change in specific volume during vaporization__________________________________ V[g Cubic_____________________________________________ cu Cubic footi__________ ___________________________ cu ft Cubic feet per minute_______________________________________________________ .cfm Cubic feet per second_________ ::cfs Decibel___________________:db Degree*---------------------------------------- ----------------------------------------------------------------- deg or Degree centigrade_________________________________________________________________ C Degree FahrenheitF Degree Kelvin___:K Degree Reaumur1__________________________________________ __________ R Density, Weight per unit volume. Specific weight-_______________ ________ d or p (rho) Diameter___ ________________ ,.Z> or diam Direct-current (as adjective).. Distance, linear.. ----------- d-rC Dry saturated vapor, Dry saturated gas at saturation pressure and temperature, vapor in contact with liquidSubscript g Entropy. (The capital should be used for any weight, and the small lettef for unit_ weight)____ .5 or s Feet per minute. ...fpm' Feet per second___ Foot. Foot-pound_________________ --fps ___ ft _ft-Ib Foot-pound-second (system).. __ fps Force, total load____________ Freezing point.......................... Gallon. Gallons per minute.. ___ F --ip --gal -gpm Gallons per second-. Gram______________ Gram-calorie_______ Head. - -gps ~g --g-cal ..H or h. Heat content, Total heat. Enthalpy. (The capital should be used for any weight and the small letter for unit weight) -H or h- Heat content of saturated liquid. Total heat of saturated liquid, Enthalpy of saturated liquid, sometimes called heat of the liquid. -ftf. Heat content of dry saturated vapor, Total heat of dry saturated-vapor, Enthalpy of dry saturated vapor.. ftg Heat of vaporization at constant pressureHorsepower. or Afg _hp Horsepower-hour. Hour Inch.. .Jip-hr ___ .hr Inch-pound__________ .in.-lb' Indicated horsepower. _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)___ __________U or u Kilogram!kg Kilowatt. Kilowatthour... ___kw ..kwhr Length of path of heat flow, thickness. ____ L Load, total___________________________ _____ W Mas? Mechanical efficiency__________ ...... mass ------ Mechanical equivalent of heat.. Melting point.________________ _mp Meter____ _____________ ___... It is recommended that the abbreviation for the temperature scale, F. C, K. be included in expressions for numerical temperatures but, wherever feasible, the abbreviations for degree be omitted; as 68 F. 822 CHAPTER 48. ABBREVIATIONS, SYMBOLS, STANDARDS p (mu) mph ..mm min Mnl .... ............. ............... Ounce -------------------------------------------------------------1--------------- Pound-- Power, Horsepower, Work per unit time mol. wtf mnl oz Jb Jp Pressure, Absolute pressure. Gage pressure, Force per unit area-i. 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 per minute- _rpm Saturated liquid at saturation pressure and temperature, Liquid in contact with vapor________________________________ Subscript f Seconds--- --------- :---------1-------------------------------------------------------:----------- -------------- .sec Specific gravityJ------- _spgr Specific heat- _sp ht or c Specific heat at constant pressure-------- ------------------Cp Specific heat at constant volume----Specific volume. Volume per unit weight, Volume per unit mass.. -Zv __v Square foot____________________________________:----------:-----------Square inch__ _sq ft _sq in. Temperature (ordinary) F or C. (Theta is used preferably only when t is used for Time in the same discussion)______________________;------------------------- 1 or 0 (theta) Temperature (absolute) F abs or K. (Capital theta is used preferably only when small theta is used for ordinary temperature)--------------------------T or 0 (capital theta) Thermal conductance4 (heat transferred per unit time per degree)------------------------------ C kA L h - tt Thermal conductance per unit area. Unit conductance (heat transferred per unit time per unit area per degree)---------------------------- :------------------------------ C_ 1 g Co. = ~AT~ RA A(h -l,) ft 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 / = t4- <i - <i -7 (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)------------.------------------- V g A V <Tenns ending mtoy designate properties independent of size or shape, sometimes called specific proper ties. Examples: conductivity, resistivity. Terms ending once designate quantities depending not only on the matArta!, but also upon size and shape, sometimes called total Quantities. Examples; conductance, transmittance. Terms ending ion designate rate of heat transfer. Examples: conduction, transmission. 823