Document YjmQ8jY65xkyvwNjJy62bJ4bD

HEATING VENTILATING AIR CONDITIONING GUIDE 1941 Table 3 can also be used for calculating the free convection rate of transmission for various commercial shapes such as pipes and ducts. These calculations are simplified by the use of the factors in Tables 4 aiid 5. Table 4 gives factors by which the values in Table 3 must be Table 6. Heat Losses from Horizontal Bare Steel Pipes Expressed in Blu per hour per linear foot per degree Fahrenheit difference in temperature between the pipe and surrounding still air at 70 F Nominal Pipe (Inches) Vi i% ifi ih 2 2H 3 3Vi 4 5 6 8 10 12 120 F Hot Water . 150 F 180 F 210 F 227.1 F (5 Lb) Steam 299.7 F (50 Lb) 337.9 F (100 Lb) 50 F 0.455 0.555 0.684 0.847 0.958 1.180 1.400 1.680 1.900 2.118 2.580 3.036 3.880 4.760 5.590 80 F 0.495 0.605 0.743 0.919 1.041 1.281 1.532 1.825 2.064 2.302 2.804 3.294 4.215 5.180 6.070 Temperature Difference 110 F 0.546 0.666 0.819 1.014 1.148 1.412 1.683 2.010 2.221 2.534 3.084 3.626 4.638 5.680 6.670 140 F 0.584 0.715 0.877 1.086 1.230 1.512 1.796 2.153 2.433 2.717 3.303 3.886 4.960 6.090 7.145 157.1 F 0.612 0.748 0.919 1.138 1.288 1.578 1.883 2.260 2.552 2.850 3.470 4.074 5.210 6.410 7.500 227.7 F 0.706 0.866 1.065 1.324 1.492 1.840 2.190 2.630 2.974 3.320 4.050 4.765 6.100 7.490 8.800 267.9 F 0.760 0.933 1.147 1.425 1.633 1.987 2.363 2:840 3.215 3.590 4.385 5.160 6.610 8.115 9.530 Table 7. Heat Loss from Horizontal Bare Bright 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 Size (Inches) H l IiKf| 2 2K 3 3K 4 4S K 6 8 Hot Water (Type E Copper Tube) j Steam (Standard Pipe Size Pipe) 120 F 150 F | 180 F 210 F 1 227.1 F (5 Lb) 297.7 F (50 Lb) 1 337.9 F i (100 Lb) Temperature Difference 50 F 0.180 0.236 0.290 0.340 0.390 0.490 0.580 0.680 0.760 0.940 1.020 1.160 1.460 80 F 0.210 0.275 0.338 0.400 0.463 0.525 0.675 0.788 0.888 1.000 1.200 1.375 1.725 110 F 0.218 0.291 0.354 0.418 0.473 0.600 0.709 0.848 0.946 1.045 1.255 1.410 1.820 140 F 0.229 0.307 0.373 0.443 0.507 0.628 0.750 0.871 1.000 . 1.107 1.320 1.500 1.890 157.1 F 0.299 0.357 0.440 0.510 0.598 0.719 0.840 0.987 1.114 1.210 1.335 1.465 1.685 2.100 227.7 F 0.338 0.408 0.492 0.571 0.671 0.813 0.953 1.107 1.235 1.361 1.495 1.670 1.890 2.373 267.9 F 0.355 0.418 0.523 0.598 0.710 0.851 1.008 1.165 1.307 1.456 1.488 1.755 1.942 2.510 730 CHAPTER 42. PIPE AND DUCT INSULATION multiplied to obtain the free convective transfer from various shapes whose characteristic dimensions are 24 in. or over, and Table 5 gives the factors to be used in conjunction with the factors in Table 4 for obtaining the free convection from Table 3 for pipes and ducts whose characteristic dimensions are less than 24 in. Table 8. Heat Loss from Bright Copper Pipe Given One Thin Coat of Clear Lacquer Expressed in Btu per hour per linear fool per degree Fahrenheit between the pipe and surrounding still air at 70 F Nominal Pipe firm (Inches) K K l iK IK 2 2K 3 3K 4 4K 5 6 8 Hot Water (Type K Copper Tube) Steam (Standard Pipe Size Pipe) 120 F 150 F 180 F 210 F 227.1 F (S Lb) 297.7 F (50 Lb) 337.9 F (100 Lb) Temperature Difference SO F 0.240 0.320 0.390 0.470 0.540 0.690 0.840 0.960 1.100 1.241 1.480 1.700 2.200 80 F 0.265 0.356 0.437 0.537 0.612 0.762 0.937 1.025 1.250 1.400 1.685 1.936 2.500 HOF 0.282 0.373 0.463 0.554 0.645 0.818 0.991 1.135 1.318 1.480 1.790 2.052 2.630 140 F 0.307 0.414 0.507 0.614 0.714 0.892 1.085 1.270 1.442 1.556 1.965 2.272 2.854 157.1 F 0.401 0.477 0.598 0.700 0.830 1.005 1.178 1.400 1.580 1.750 1.910 2.130 2.450 3.120 227.7 F 0.461 0.571 0.681 0.812 0.966 1.164 1.361 1.625 1.845 2.040 2 240 2.415 2.810 3.425 267.9 F 0.478 0.578 0.710 0.840 0.990 1.201 1.420 1.700 1.905 2.130 2 350 2.610 2.990 3.730 Table 9. Heat Loss from Horizontal Tarnished Copper Pipe Expressed in Btu per hour per linear foot per degree Fahrenheit between the pipe and surrounding stiU air at 70 F Nominal Pipe Size (Inches) 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 (50 Lb) 337.9 F (100 Lb) Temperature Difference 50 F 80 F no F 140 F 157.1 F 227.7 F 267.9 F K 0.250 0.287 0.300 0.321 0.433 0.500 0.530 lK 0.340 .0.440 0.381 0.475 0.409 0.509 0.429 0.536 0.533 0.636 0.543 0.746 0.654 0.803 iK 0.500 0.559 0.618 0.622 0.764 0.878 0.934 iK 0.580 0.656 0.710 0.750 0.904 1.053 1.120 2 0.730 0.825 0.890 0.957 1.101 1.273 1.364 2K 0.880 1.000 1.091 1.143 1.305 1.490 1.605 3 1.040 1.175 1.272 1.343 1.560 1.800 1.940 3K 1.180 1.350 1.454 1.535 1.750 2.020 2.170- 4 1.460 1.500 1.635 1.715 1.941 2.240 2.430 4K 2.131 2.465 2.650 5 1.600 1.812 1.980 2.071 2.387 2.770 2.990 6 1.840 2.125 2.270 2.430 2.740 3.210 3.440 8 2.400 2.685 2.910 3.110 3.310 4.050 4.370