Document QM4KQ8MgrbQqZmyMo00o0RNYo

10 CHAPTER 1 . . 1946 Guide Ventilation: The process of supplying or removing air, by natural or. mechanical means, to or from any space. Such air may or may not have been conditioned. (See Air Conditioning.) .*' Volume, Specific: The volume of a substance per unit niass; the reciprocal of density. Units:. cubic feet per pound, cubic centimeters per gram, etc. Warm Air Heating System: A warm air heating plant consists of a heating unit (fuel-burning furnace) enclosed in a casing, from which the heated air is distributed to the various rooms of the building through ducts. Warm Air Heating System, Gravity: A warm air heating system in which the motive head producing flow depends on the difference in weight between the heated-air leaving the casing and the cooler air entering the bottom of the casing. Warm Air Heating System, Mechanical: A warm.air heating system in which ..circulation of air is effected by a fan. Such a system may include air cleaning devices. CHAPTER 2 _^bbreutation6 anJSfm u Standard Abbreviations; Standard Symbols; Greek Alphabet; Conversion Equations; Graphical Symbols for Piping, Ductwork, Heating and Ventilating, Refrigerating; Identification of Piping by Color; Specific Heat Table THIS chapter contains information regarding abbreviations, symbols, and conversion equations, which are of particular interest to the engineer engaged in heating, ventilating, and air conditioning. ABBREVIATIONS Abbreviations are shortened forms of names and expressions employed in texts and tabulations and should not generally be used as symbols in equations. Most of the following abbreviations have been compiled from a list of approved standards l. In general the period has been omitted in all abbreviations except where the omission results in the formation of an English word. Additional abbreviations applying to individual chapters will be found at the end of Chapters 3, 4, 5, 7, 39, 41, and 43. Absolute..:--------------------- -............................... -......................................... -................. ..^abs Air horsepower.... ................................................ --t........ -................................-........... air hp Alternating-current (as adjective)...................... .....................1....................................... a-c Ampere........ .................................................. ;.... -............. -........... -........ -........... --..... .-amp Ampere-hour..^.......................... -............. 1.......... ..................................-....... -.......... amp-hr Atmosphere....... ........................ Average... ........ ........... -........... Avoirdupois.......... ........ ........... Barometer......... ..... .................. Boiling point--........................... ......atm ......avg ....avdp ..... bar. ......bp Brake horsepower..................... Brake horsepower-hour............ British thermal unit.................. British thermal units per hour. Calorie........................................ __ bhp :bhp-hr ..... Btu ....Btuh ....... cal Centigram........... .................................... .... ..:....................................=.....................:.....--leg Centimeter......................... .............. ................................................................ ............... .cm. Ceritimeter-gram-second (system)................................ ....................................................cgs Cubic.......... ........... ................. ....................................... ......... 1........ ................ ................. cu Cubic centimeter__ ................................................................-.......... .................cu. cm or cc Cubic foot... Cubic feet per minute. Cubic feet per second.. Decibel________ _____ Degree*....________ ..... ;.cu ft ....... cfm ......... cfs ......... db .deg or Degree, Centigrade............................:__`..................... ;............... -......... ....................... C Degree, Fahrenheit.........................................-..................................................................... F Degree, Kelvin!........... ........................... ....... ...................................:... ................. ..... ...... K Degree, Reaumur!................... ............. !..... .............. I.......--.....'.........._:!.... .............. R Diameter................. ......... 1........................... ....................... ........... !..............;....T........ diam `Abbreviations for Scientific and Engineering Terms, 210.1-1941 {American Standards Association). It is recommended that the abbreviation for the temperature scale. F, C, K, be included in expressions tor numerical temperatures but, wherever feasible,- the abbreviations for degree be omitted; as 68 F.-