Document Qvex48voL8wBjb91Rgkga7J6

:870 CHAPTER 34 1958 Guide Table 1. Average Maximum Water Main Temperatures* StatE^ ^ * Citt J fa' eu H H Citt Ala. Ark. Aris. Calif. > Colo. Conn. D. C. Del. Fla. Ga. 111. Ind. Iowa Kans. Ky. La. Me. Md. Birmingham............ 84 Mobile........................ 80 little Rock.......... 83 Phoenix.-................... 82 Tucson........................ 80 -Anaheim.................... 60 Berkeley.................... 69 Fresno........................ 80 Fullerton................... 75 Glendale.................... 68 Los Angeles.............. 80 Oakland..................... 69 Ontario...................... 70 Pasadena................... 82 Pomona...................... 75 Riverside................... 78 Sacramento.............. 72 San Bernardino -- 65 San Diego................. 84 San Francisco.......... 71 Whittier...................... 76 Denver....................... 75 Bridgeport................ 66 Hartford.................... 73 New Haven.............. 76 Waterbury................ 72 Washington.......... 84 Wilmington.............. 83 Jacksonville.............. 86 Miami......................... 82 Tampa........................ 77 Atlanta....................... 85 Macon......... .......... 80 60 Chicago...................... 78 Cicero......................... 76 Evanston.................. 73 Moline........................ 83 Peoria......................... 67 Rockford.................... 59 Springfield................ 82 Evansville................ 88 Gary............................ 75 Indianapolis............. 84 South Bend.............. 61 Terre Haute............. 82 Cedar Rapids.......... 78 Des Moines.............. 77 Sioux City................ 62 Concordia.................. 57 Kansas City............ 86 Topeka....................... Wichita...................... 72 Louisville.................. 85 Baton Rouge............ 85 New Orleans............ 90 Shreveport............. 88 Augusta................... 60 Baltimore................ 75 Minn. Mo. Nebr. Nev. N. H. N. J. N. C. N. M. Ohio Okla. Boston........................ Cambridge................ Fall River................. Lowell........................ Lynn........................... New Bedford........... Salem.......................... Worcester.................. Detroit....................... Flint............ 4.............. Grand Rapids......... Highland Park. Jackson..................... Kalamazoo.............. Lansing...................... Saginaw.................... Duluth.................. .Minneapolis............ St. Paul. .......----Jefferson City........ Kansas City.......... Springfield.............. St. Joseph......... . St. Louis.................. Springfield............ Lincoln..................... Omaha...................... Reno......................... Manchester............. Jersey City............. Newark.................... Paterson ...'............ Trenton.................... Albany..................... Buffalo...................... Jamaica.................... Mt. Vernon............ New Rochelle........ New York.............. Rochester................ Schenectady.......... Syracuse.................. Utica......................... Yonkers................... Asheville.................. Charlotte................. Raleigh................... Winston-Salem-- Albuquerque.......... Akron........................ C&nton...;.............. Cincinnati.............. Cleveland--........ Columbus................ Dayton.................. Lakewood................ Springfield.............. Toledo....................... Oklahoma City ... State Ore. Pa. R. I. S. C. S. D. Tenn. Texas Utah Va. Wash. W. Va. Wis. Tulsa........................ Eugene.................... Portland................. Altoona.................... Erie.......... .............. Johnstown.............. McKeesport............ Philadelphia......... Pittsburgh............. Providence............. Charleston............. Greenville............... Spartanburg......... Rapid City............ Chattanooga.......... Knoxville............... Memphis................. Nashville............... Amarillo................. Austin ... .............. Beaumont............... Dallas...................... El Paso ................... Fort Worth............. Galveston............... Houston................. Port Arthur........... San Antonio.......... Wichita Falls......... Logan....................... Salt Lake City.. .. Fredericksburg.... Lynchburg............. Norfolk................... Richmond.............. Olympia................. Seattle.................... Spokane.................. Tacoma................... Charleston............. Huntington........... Wheeling................. LaCrosse................. Madison.................. Milwaukee............. Racine.................... 86 60 65 74 75 j 74 Prov ince Alta. B. C. Ont. P.E.I. Que. Calgary............. Vancouver.. London.............. Toronto............. Charlottetown.. Montreal............ Quebec............. h These averages taken from various city water main locations, with some actual values slightly and some lower than values shown. Some values were supplied by H. E. Degler, Marley Company. were obtained from City Water Department records. The highest values given by the various au are usually those listed. bulb temperature, but the same humidity ratio, more water can be ab sorbed per pound of dry air in passing through the washer, that the humidifying effectiveness of the washer is not adversely ^ by operation at the higher wet-bulb temperature. The analysis ot t process occurring in the washer itself is the same as that explained un Method 1. The final desired conditions are secured by adjusting ^ amount of preheating to give the required wet-bulb temperature at e trance'to the washer.' Method 3. Even if heat is added to the spray water, the mixing ring in the washer itself may still be regarded as adiabatic. The Spray Apparatus 871 point of the mixture should move in a direction determined by the specific enthalpy of the heated spray as explained in Chapter 3. It is possible,: by elevating the water temperature, to raise the air temperature, both dry-bulb and wet-bulb, above the dry-bulb temperature of the entering air. In each of the methods, 1, 2 or 3, the air leaving the air washer may require reheating to produce in the conditioned space the required drybulb temperature and relative humidity. DEHUMIDIFICATION AND COOLING WITH AIR WASHERS : Lowering of the wet-bulb temperature, of an air vapor mixture can be accomplished by an air washer if the temperature of the spray water is lower than the wet-bulb temperature of the air. Moisture removal is obtained when the spray water temperature is. lower than the dew-point of the entering air. In these cases the final dry-bulb temperature and: relative humidity of the leaving air are dependent upon the design factors' of the air washer. ' Both sensible and latent heat are removed in the process of dehumidi fication by cold spray water. Abstraction of sensible heat occurs during the entire time that the air is in contact with the spray medium. Latentheat removal takes place as condensation occurs. Therefore, the lower the spray temperature, the greater the amount of moisture removal per pound of dry air, all other conditions remaining the same. Washers with two or more banks of spray are usually selected for de-. humidifying installations, whether for comfort or industrial installations'. Generally such air washers cool the air to within one or two degrees (Fahren heit) of the leaving spray water temperature; this differential will increase somewhat when the difference between the entering wet-bulb and leaving dew-point is relatively large. Where a limited supply of cold water is available, multiple stage washers inny be used to great advantage. In such washers the cool water is pumped through the multiple spray systems in series and counterflow to the air hw. 311 arrangement brings the delivery air in contact with the coldest water, securing a maximum amount of cooling and saving water. When using cold well water or water from city water mains, care should dc used to secure accurate data on the water temperatures. Table 1 lists some approximate water main averages which may be used as a guide, but ey should be verified from local records. This is particularly true with p. y ma*n temperatures. In the case of well water temperatures, " snows the approximate temperatures of water to be expected from wells at depths of 30 to 60 ft. lat^r Was^ers fr dehumidifying and cooling usually have separate recircu- waf11^ PDJDps. These pumps deliver a mixture of cold and recirculated eith f con*,rl a three-way valve. The valve may be actuated tr ,,er ^ thermostat in the washer outlet, or by a humidity or other con firm the space being conditioned. e a washers for dehumidifying are very often furnished with direct w PD!n or water cooling coils within the washer space, in which case r lor the washer sprays is entirely recirculated. APPARATUS FOR DIRECT HUMIDIFICATION to^the11^!^8 may he divided into two general types which are, according method of operation: (1) indirect, such as the air washer, which