Document Z1N83bZ4Kxk4dwr6b7mbEjB8

HEATING VENTILATINC AIR CONDITIONING GUIDE 1942 (dollars) -s- 13,000 (Btu) X 2000 (lb) X 0,55 (efficiency) = $0,804. The total cost of heat lost per year = 0.804 X-181.6 (thousand Btu) = $146.00. (A closely approximate solution of such a problem may be made quickly by the use of the estimating chart given in Fig. 1.) Table 3. Heat Loss from Bright Copper Pipe Given One Thin Coat of Clear Lacquer Expressed in Btu per hour per linear foot per degree Fahrenheit between the pipe and surrounding still air at 70 F Nominal (Inches) Hot Water (Type K Copper Tube) Steam (Standard Pipe Size Pipe) 120 F 150 F 180 F 227.1 F (5 Lb) 297.7 F (50 Lb) 337.9 F (100 Lb) Temperature Difference 50 F 80 F 110 F 140 F | 157.1 F 227.7 F 267.9 F H SA 0.240 0.320 0.265 0.356 0.282 0.373 0.307 0.414 0.401 0.477 0.461 0.571 0.478 0.578 1 0.390 0.437 0.463 0.507 0.598 0.681 0.710 0.470 0.537 0.554 0.614 0.700 0.812 0.840 1H 0.540 0.612 0.645 0.714 0.830 0.966 0.990 2 0.690 0.762 0.818 0.892 1.005 1.164 1.201 2H 0.840 0.937 0.991 1.085 1.178 1.361 1.420 3 0.960 1.025 1.135 1.270 1.400 1.625 1.700 3K 1:100 1.250 1.318 1.442 1.580 1.845 1.905 4 1.241 1.400 1.480 1.556 1.750 2.040 2.130 5 1.480 i.685 ' 1.790 1.965 1.910 2.130 2.240 2.350 2.415 ' 2.610 6 1.700 1.936 2.052 2.272 2.450 2.810 2.990 8 2.200 2.500 2.630 2.854 3.120 3.425 3.730 Table 4. Heat Loss from Horizontal Tarnished Copper Pipe Expressed in Btu per hour per linear foot per degree Fahrenheit between the pipe and surrounding still air at 70 F Nominal Pipe (Inches) A 3A 1 m1M m. 2 3 3H 4 4A 5 6 8 Hot Water (Type K Copper Tube) Steam (Standard Pipe Size Pipe) 120 F ISO F 180 F 210 F . 227.1 F (5 Lb) 297.7 F (SO Lb) 337.9 F (100 Lb) Temperature Difference - SO F 0.250 0.340 0.440 0.500 0.580 0.730 0.880 1.040 1.180 1.460 1.600 1.840 2.400 80 F 0.287 0.381 0.475 0.559 0.656 0.825 1.000 1.175 1.350 1.500 1.812 2.125 2.685 110 F 0.300 0.409 0.509 0.618 0.710 0.890 1.091 1.272 1.454 1.635 1.980 2.270 2.910 140 F 0.321 0.429 0.536 0.622 0.750 0.957 1.143 1.343 1.535 1.715 2.071 2.430 3.110 157.1 F 0.433 0.533 0.636 0.764 0.904 1.101 1.305 1.560 1.750 1.941 2.131 2.387 2.740 3.310 227.7 F 0.500 0.543 0.746 0.878 1.053 1.273 1.490 1.800 2.020 2.240 2.465 2.770 3.210 4.050 267.9 F 0.530 0.654 0.803 0.934 1.120 1.364 1.605 1.940 2.170 2.430 2.650 2.990 3.440 4.370 774 CHAPTER 43. PIPE AND DUCT HEAT LOSSES HEAT LOSSES FROM INSULATED PIPES The conductivities of various materials used for insulating steam and hot water systems- are given in Table 8. They are given as functions of the mean temperatures or the mean of the inner and outer surface tem- Table 5. Radiating Surface-per Linear Foot of Pipe Nominal Pipe Size (Inches) l 1 1A 114 IISurface Area (Sq Ft) 0.22 0.275 0.344 0.435 0.498 Nominal Pipe Size (Inches) 2 2H 3 m 4 Surface Area (So Ft) Nominal Pipe gas (Inches) 0.622 0.753 0.917 1.047 1.178 l 5 6 8 10 12 Surface Area (So Ft) 1.456 1.734 2.257 2.817 Table 6. Radiating Surface, per Linear Foot of Copper Tubing Outside diameter A in. greater than nominal site Tube Size (Inches) Vl % 1 1A iA Surface Area (So Ft) 1 0.164 0.229 0.295 0.360 0.426 Tube Size (Inches) 2 m 3 3A 4 Surface Area (So Ft) 0.556 0.687 0.818 0.949 1.080 Tube Size (Inches) 5 6 8 Surface Area (So Ft) 1.342 1.604 2.128 Table 7. Areas of Flanged Fittings, Square Feet Nominal Pipe Size (Inches) Flanged Coupling 90 Dbg Ell Long Radius Ri.i. Tee Cross Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy Standard Extra Heavy 1 iH 2iA 2H 3 3H 4 4H 5 6 8 10 12 0.320 0.383 0.477 0.672 0.841 0.945 1.122 1.344 1.474 1.622 1.82 2.41 3.43 4.41 0.438 0.795 0.510 0.957 0.727 1.174 0.848 1.65 1.107 2.09 1.484 2.38 1.644 2.98 1.914 3.53 2.04 3.95 2.18 4.44 2.78 5.13 3.77 6.98 5.20 10.18 6.71 13.08 1.015 1.098 1.332 2.01 2.57 3.49 3.96 4.64 5.02 5.47 6.99 9.76 13.58 17.73 0.892 1.084 1.337 1.84 2.32 2.68 3.28 3.96 4.43 5.00 5.99 8.56 12.35 16.35 1.083 1.235 1.575 1.622 2.07 1.340 1.481 1.925 1.943 2.53 1.874 1.815 2.68 2.38 3.54 2.16 2.54. 3.09 3.32 4.06 2.76 3.21 4.05 4.19 5.17 3.74 3.66 5.33 4.77 6.95 4.28 4.48 6.04 5.83 7.89 4.99 5.41 7.07 7.03 9.24 5.46 6.07 7,72 7.87 10.07 6.02 6.81 8.52 8.82 10.97 7.76 7.84 10.64 10.08 13.75 11.09 10.55 14.74 13.44 18.9' 15.60 15.41 20.41 19.58 ?' 18.76 19.67 26.65 24.8 --rfie losses Including areas of accompanying flanges bolted to the fitting. temperature peratures of the insulations. It should be emphasized thaft the case of average values obtained from a number of tests made ofocity are very material, also that all variables due to differences in thicjause of the fact and air conditions are eliminated. Individual manufaincrease only the will, of course, vary in conductivity to some exten+change the internal ; 775