Document pmEeB4jBJpByZZdNJNnwZYpMa

Heating Ventilating Air Conditioning Guide 1939 the corrected U is 0.188. The average number of degree-days in Albany, from Table 3 for a full average heating season is 6580, and the number of building load units is 650' Substituting in Equation 3: F = 0.188 X 6580 X 650 = 804,076 cu ft of gas. Estimating Oil Consumption Unit fuel consumption factors for oil, similar to those for gas in Table 4 are given in Table 6. The factors in Table 6 apply only to an inside design temperature of 70 F and an outside design temperature of 0 F. For other Table 4. Factors for Estimating Gas Consumption Btu Value or Gas perCu Ft 500 535 800 1000 Hot Water Cu Ft Gas per Degree-Day per Sq Ft Radiator Up to 500 Sq Ft 500 to 1200 Sq Ft Over 1200 Sq Ft 0.142 0.132 0.089 0.071 0.135 0.126 0.085 0.068 0.128 0.120 0.081 0.065 Steam Warm Air Cu Ft Gas per Degree-Day per Sq Ft Radiator Up to 500 Sq Ft 300 to 700 Sq Ft Over 700 Sq Ft Cu Ft Gas per Degree-Day per 1000 Btu Hourly Design Heat Loss Gravity Fan Systems 0.242 0.226 0.151 0.121 0.231 0.215 0.144 0.115 0.220 0.206 0.137 0.110 0.855 0.800 0.534 0.428 0.820 0.766 0.513 0.410 i 1 Therm Gas Consumption in Therms per Degree-Day 100,000 Btu 0.000708 0.000675 0.000642 0.00121 0.00115 0.00110 0.00428 0.00409 "Abstracted from Comfort Heating, American Gas Association, 1938. Table 5. Correction Factors for Outside Design Temperatures FOutside Design Temp. Deo FInside Design Temp. Deg Multeplt Values in Tables 4, 6 and 7 bt -20 -10 0 +10 +20 70 70 70 70 70 \ 0.778 0.875 0.000 1.167 1.400 outside design temperatures, the constants in Table 6 must be multiplied by the values in Table 5 as explained under Estimating Gas Consumption. is ITable 6 assumes the use of oil with a heating value of 140,000 Btu per gallon. For other heating'values, multiply the values in Table 6 by the ratio of 140,000 divided by the heating value per gallon'of fuel being used. Example 7. What would be the estimated seasonal oil consumption of a boiler- d burner unit in Minneapolis of a building having a calculated heat loss of 192;000 Btu per ^ hour, burning 144,000 Btu per gallon oil and operating at a seasonal efficiency of 60 jj per cent, if the outside design temperature for Minneapolis is --20 F, and the inside design temperature is 70 F? "- Solution. From Table 6, under 60 per cent efficiency and opposite the bottom column, 13 -find the uncorrected V to be 0.00476 gal per 1000 Btu hourly heat loss. 244 n Chapter 12. Heat and Fuel Utilization r- Tnhle 5 the correction multiplier for --20 F outside design temperature is 778OD1Solving, 0.778 X 0.00476 = 0.00370. Making a further correction for the heating 0.0iw03f7t nA/ 144 000 = 0.0036 gal per 1000 Btu per hour calculated heat loss per degree- dparoyF*Fb-irleomm Table 3, the average degree-days for Minneapolis pj 1Q2. Substituting in Equation 3: number 7850, and from the F = 0.0036 X 7850 X 192 = 5426 gal. Table 6. Unit Fuel Consumption* Constants for OiLb Unit Eppicienct in Per Cent 40 50 60 70 80 Gal Oil per Sq Ft Steam Radiator.. 0.00172 0.00137 0.00114 0.00098 0.00086 Gal Oil per Sq Ft Hot Water Radiator........... .............. .................. 0.00108 0.00086 0.00072 0.00062 0.00054 Gal Oil per 1000 Btu per Hour Heat Loss........... ............................... 0.00715 0.00571 0.00476 0.00409 0.00358 "Based on a heating value of 140,000 Btu per gallon. bAbstracted by permission from Degree-Day Handbook (Second Edition, 1937), by C. Strock and C. H. B. Hotchkiss. Table 7. Unit Fuel Consumption* Constants for CoALb Unit 40 Lb Coal per Sq Ft Steam Radiator.. 0.0200 Lb Coal per Sq Ft Hot Water Radiator..... _ ................................. 0.0125 Lb Coal per 1000 Btu per Hour Heat Loss.......................................... 0.0825 Eppicienct dt Per Cent 50 0.0160 60 0.0133 70 0.0114 0.0100' 0.0084 0.0072 0.0666 0.0550 0.0471 80 0.0100 0.0063 0.0412 Based on a heating value of 12,000 Btu per pound. bAbstracted by permission from Degree-Day Handbook, (Second Edition, 1937), by C. Strock and C. H. B. Hotchkiss. Estimating Coal or Coke Consumption Coal or coke consumption estimates can be made in exactly the same way as for oil. The uncorrected values of U are given in Table 7. These constants apply only to inside design temperatures of 70 F and an outside design temperature of 0 F, and correction must be made for other con ditions by use of the multiplying factors in Table 5. Table 7 is based on 12,000 Btu per pound coal and for other heating values of coal, values in Table 7 must be multiplied by the ratio of 12,000 divided by the heating value of fuel used. Estimating Steam Consumption . In estimating steam consumption the efficiency is not' ordinarily a factor and is assumed at 100 pier cent. Ordinarily low pressure steam 245