Document 37yxk56qNbmyMYvjYwdkxvg0

556 CHAPTER 37 1960 Guide Table 8 .... Degree Day* for Industrial Heating in Various Gties of the United Stated Anaoof Tofeft for a Nermof Hoofing Soaton D-nr-m Dny* 45F 55F Bose Bom Or 45F 55F Bom Bom 45F 55F Bom Bom Ala... Birmingham......... Mobile................... Montgomery......... Arii.. Phoenix................. Yuma..................... Ark... Fort Smith.. Little Rock.. Cal... Eureka............. Fresno.............. Independence.. Red Bluff............. Sacramento......... San Diego............. San Francisco.. . San Luis Obispo. Denver............. Grand Junction-- Pueblo.............. Coon. Meriden........ New Haven. D.C. . Washington . Fla... Pensacola... Ga.... Atlanta__ Augusta... Macon....... Savannah.. Idaho. Boise......... Lewiston.. Pocatello.. 1045 1034 2161 Md... Mass. 3440 3433 3261 734 3237 Miss.. Mo... 2487 127 1165 661 711 231 2814 Baltimore................ 986 2491 Boston.................... 1787 Nantucket.............. 1514 Alpena..................... Detroit.................... Grand Haven......... Grand Rapids........ Houghton................ Lansing................... Marquette............... Port Huron............. Saginaw................... Sault Ste. Mane 3131 2240 3699 2405 2332 4029 2537 3713 2630 2312 4049 Duluth..................... 4419 Minneapolis........... 3309 4796 St. Paul................... 2497 3603 3419 5499 4089 5918 3435 4177 6112 4444 5842 4275 4552 6575 6774 5417 6572 5497 Okla.. Ore... R. I.. S. C.. Vicksburg............... 468 Columbia................ Hannibal................. Kansas City........... St. Louis................. Springfield.............. 1252 1635 1463 1186 982 2939 3231 2980 2745 2423 3736 5874 Helena..................... 2843 5071 Kalispell.................. 2874 5131 Lincoln.................... 3023 3850 2291 4152 Valentino................ 2833 4801 111.... Cairo........... Chicago----Springfield.. 749 1969 1677 Nev. . Winnemucca........... 1670 3468 N. H. CoQcord................... 2646 4640 Dayton___ Sandusky.. Toledo Oklahoma City.. Baker........ Portland.. Roseburg.. Erie................. Harrisburg.. . Philadelphia.. Scranton........ Pittsburgh-- Block Island.. Charleston....... Columbia!............. Greenville............. Huron........... Pierre........... Rapid City. Yankton....... Chattanooga.. Knoxville....... Memphis........ Nashville........ Abilene............. Amarillo.................. El Paso............ Fort Worth___ Galveston........ Houston........... Palestine.......... San Antonio... Modena.............. Salt Lake City. 3147 3425 3757 4307 1911 3837 3236 2695 3755 336 759 1502 5673 5234 1741 1284 419 1678 786 919 754 43 110 484 305 Ind... Evansville___ Indianapolis.. la..... Charles City.. Davenport-- Dea Moines... Dubuque........ Keokuk.......... Sioux City___ Concordia... Dodge City.. Topeka......... Wichita........ Ky... Lexington.. Louisville. . La... New Orleans.. Shreveport.. . Me... Eastport. Portland.. 799 1397 3370 2296 2440 162S 1926 2894 4142 4180 4468 3579 4732 N. J.. N. M. N.Y.. 1652 1385 1518 1152 N.D. Ohio. 2956 5236 2530 4572 Atlantic City......... 1123 2901 Sante Fe................. 1634 3106 Albany..................... Binghamton............ Buffalo.................... Ithaca.................... New York............... Oswego.................... Rochester................ 2018 2073 2359 2412 1098 2274 2341 4302 4296 4316 4023 3089 4363 4231 Charlotte................ Raleigh.................... Wilmington............. 172 1388 718 229 1080 729 Bismarck................. 3831 6468 Williston................. 4616 6399 Cincinnati............... 1376 3003 Cleveland................ 1525 3795 Columbus.............. 1600 3255 Burlington. Northneld.. Lynchburg Norfolk.... Richmond.. North Head.. Seattle............ Spokane......... Tacoma.......... Walla Walla.. Elkins............. Parkersburg.. Green Bay.. La Crosse.. Madison___ Milwaukee-. Wyo... Cheyenne................ 2500 Lander............. 4984 7121 1928 1496 1895 2062 2185 3672 2365 2565 3327 2784 $331 3992 4850 4617 4700 $450 From a later cmroe. OmA*4,byC.8teocksdC. H. B. Hotchkiaa (The Industrial Pies, m7. pj>. US-IM). VkUaa not oowdinaMd with T*bU 1 a {ran Estimating Fuel Consumption for Space Heating 557 erage indoor temperature of approximately 70 F is assumed throughout the period. If an average indoor temperature other than approximately 70 F is to be used, the numb?? of degree days should be obtained for the new base. Example 7: An eight-story building in Pittsburgh is operated with a daytime temperature of 70 F. The calculated heat loss is 10,500 Btu per (hr) (degree temperature difference). What is the estimated average yearly steam consumption for building heating? Solution: Since the average indoor temperature is approxi mately 70 F, the degree days from Table 2, based on 70 r may be used. Therefore, from Table 2, Pittsburgh has 5048 degree days per normal season. Inserting in Equation 5: 10,500 X 24 X 5048 F 1,272,000 lb of steam. 1000 Consideration has been given to the difference in steam utilization of different types of buildings, and Table 7 shows actual average units for these various types. These figures were obtained from operating results in 896 buildings located in all sections of the United States. Being averages, and for small groups in each type, the figures may need considerable modification to allow for local variations. It should be especially noted that the steam used for heating water for service is not included in the values given in Table 7. Additional figures are to be found in a paper presented before the Society." Example 8: A store in Philadelphia with a heating system designed to maintain 70 F indoors in 0 F weather has 250,000 cu ft of heated space. What would be the estimated average yearly steam consumption of purchased steam for heating? Solution: According to Table 7, a store would use 0624 !b of steam per degree day per 1000 cu ft heated space. From Table 2, Philadelphia has 4523 degree days per normal year. Inserting in Equation 4: F - 0-624 X 250 X 4523 - 706,000 lb of steam- Degree Day as an Operaring Unit The degree day is also widely used as a of com paring the efficiency of the fuel consumption of one period with another for the same building. Since the fuel consump tion is approximately proportional to the weather (degree days), and since the periods to be compared may not have the same weather conditions, the comparison can be made only after the fuel consumptions have been computed on a comparable weather basis, that is, upon the actual number of degree days occurring for a given month and year in the city under consideration. Since fuel consumption is propor tional to the number of degree days, plant operators fre quently compute each month the fuel burned per degree day by the heating plant. The resulting unit value, by eliminating the outdoor temperature variable, indicates whether the operating efficiency of the plant is above or below the pre vious month or year. INDUSTRIAL DEGREE DAYS When estimating the heating requirements of warehouses, factories, and other buildings where the indoor temperature to be maintained differs greatly from the usual indoor tem perature range of 68 to 72 F, it is common to use degree days based on temperatures of 55 to 45 F. These are gen erally referred to as industrial degree days, and are listed in Table 8 for & number of cities using both 55 F and 45 F as the base. In general, the degree days (55 F base) are used when the temperature of the heated space is to be main tained at approximately 60 F. For an inside temperature of about 50 F, the degree days calculated on a 45 F base should be used. The industrial degree days are useful for estimating fuel consumption by comparison between localities in which the difference in degree days is not too great, and where the known fuel consumption of one building may be used to determine unit consumption per degree day. MAXIMUM DEMANDS AND LOAD FACTORS In one form of district heating rates, a portion of the charge is based upon the marrmiim demand of the building. The maximum demand may be measured in several dif ferent ways. It may be taken as the instantaneous peak or as the rate of use during any specified interval. One method is to take the average of the three highest hours during the winter. These figures ar shown for a number of buildings in Detroit in Table 9." Table 9 ____ Building Load Factors and Demands of Some Detroit Buildings BuSding OoiofieaWoa load Factor lb of Demand pot (Hour) ($q ft ED*) Clubs and Lodges........................ Hotels............................................ Printing......................................... Offices............................................. Apartments................................... Retail Stores................................ Auto Sales and Service.............. Banks............................................. Churches........................................ Department Stores..................... Theaters........................................ 0.318 0.316 0.287 0.263 0.255 0.238 0.223 0.203 0.158 0.138 0.126 0.184 0.207 0.217 0.209 0.225 0.182 0.248 0.158 0.152 0.145 0.151 These maximum demands were measured by an attach ment on the condensate meter, and therefore represent the amounts of condensate passed through the meter in the highest hours, rather than the true rate at which steam is supplied. There might be slight differences in these two quantities due to time lag and to storage of condensate in the system, but wherever this has been investigated it has been found to be negligible. The load factor of a building is the ratio of the average load to the mATtmmn load and is an index of the utilization. Thus, in Table 9, the theaters, operating for short hours, have a load factor of 0.126 as compared with the figure of 0318 for clubs and lodges. REFERENCES 1W. S. Harris and R. J. Martin: Heat transmitted to the I=B=R research home from the chimney (ASHVE Tbansaotions, Vol. 59, 1953, p. 97). *S. Konso: The Stoker-fired Warm-air Furnace tn the Re search Residence (University of Illinois, Engineering Experi ment Station Circular 39, 1939, p. 98). * Performance of a Hot Water Heating System in the I--B=R Research Home ot- the University of Illinois (University of Illinois, Engineering Experiment Station Bulletin No. 349, January 4, 1944), *W. G. Colbome: Performance of intermittently-fired oil furnaces (ASHAE Tbak&actionb, Vol. 63, 1957, p. 427). /