Document 2JYg9z3Xwm2bGEq49p3XvYMXN

454 CHAPTER 19 - ,r - 1953. Guide Table 5. Resistances of Warm Air Boot Combinations Expressed in Elbow Equivalents ; Warm Aib Boot Name op Combination Equivalent No. op ' . '90-Deg Elbows A 45-Deg Angle Boot and 45-Deg Elbow ) i B 90-Deg Angle Boot c 'Universal Boot and 90-Deg Elbow ,.i . .i D End Boot .. 2 .......... E Offset Boot '' 2M F 45-Deg Angle % G Floor Register--Second Story 3 H . " Offset 3: I Offset .2 A'Qr/ess Insulated i/ith 3 layers of air Cellasbestos paper thru 'Tight collar. . Flo. 4. Details of Bonnet and Leader of Gravity Warm-Air Furnace (From N.W.A.H. & A.C.A. Manual 5, Fourth Edition) Gravity Warm Air Systems 455 Table 6. Warm Air Carrying.Gapacity, Btuh Delivered, First Story Registers NATION No. : No. OP { . 23 4 5 1 2 3 4 5 l 2 34 5 1 2 3 4 5 1 2 3 4 5 .1 2. 3 4 5 Actual Length (Bonnet to Boot) Feet 6 4 6 8 10 m 4 6 8 10 12 14 7 4 6 8 10 12 14 16 - 18 !Yi ' 4 6 8 10 ' 12 14 16 18 20 . 22 t1 ` - fcl 1 !6,020 5,850 ,5,680 5,510 5,340 5,170 5,000 4,830 4,660 '41490 7,620 -7,400 7,180 6,970 6,760 6,540 6,320 6,110 5,890 5,680 9,400 9.140 8,870 8,600 8,340 8,070 7,810 7,540 7,270 7,010 13,360 12.970 12,590 12,210 11,830 11,450 11,080 10,700 10,320 9,950 17,620 17,020 16,530 16,040 15,550 15,050 14,550 14,050 13,560 13,060 `o g' o' o 3 a a B . .. w . 5,850 5,660 5,490 5,330 5,160 5,000 4,840 4,670 4,510 4,340 7,360 7,150 6,940 .6,730 6,520 6,320 6,110 5,910 5,700 5,500 v9,090 8,840 .8,580 8,320 8,060 7,800 7,550 7,290 7,040 6,780 12,910 12,540 12,170 11,800 11,430 11,060 10,690 10,320 9,950 9,580 16,940 16,450 15,990 15,500 15,040 14,550 14,080 13,600 13,120 12,650 5,620 5,460 5,310 5,150 4,990 4,830 4,670 4,510 4,350 4,190 7,120 6,910 6,710 6,510 6,310 6,110 5,90C 5,700 5,500 5,300 8,780 8,530 8,280 8,030 7,780 7,530 7,290 7,040 6,800 6,550 12,450 12,100 11,750 11,400 11,050 10,700 10,350 10,000 9,650 9,300 16,360 15,900 15,440 14,970 14,510 14,050 13,600 13,130 12,660 12,200 5,420 5,260 5,110 4,960 4,800 4,650 4,500 4,350 4,190 4,040 6,860 6,660 ,6,460 6,270 6,080 5,890 5,690 5,500 5,300 5,110 8,460 8,220 '7,980 `7,740 7,500 7,260 7,020 6,780 6,550 6.310 12,010 11,670 11,330 10,990 10,650 10,310 9,970 9,630 9,290 8,950 15,770 15,320 14,880 14,420 13,990 13,540 13; ioo 12,650 12,200 11,750 5,240 5,090 4,940 '4,790 4,640 4,500 4,350 4,200 4,050 3,910 6,630 6,440 6,250 6,060 5,880 5,690 5.50C 5,320 5,130 4;940 8,180 7,950 7,720 .7,490 7,260 7,030 6,800 6,560 6,330 6,100 11,610 11,290 10,95C 10,620 10,300 9,970 9,640 9,320 8,990 8,660 15,250 14,800 14,380 13,950 13,520 13,090 12,650 12,230 11,800 11,370 Notes: Carrying capacity and length of run increased with basement depth. Length of trunk and carrying capacity"of gravity extended plenum- installations should be baaed :on the 6 ft basement depth capacities. Design Procedure The steps to be taken in designing a gravity warm-air duct system are: 1. Calculate the heat loss from each room as explained in Chapters 9, 11 and 12. 2. Prepare a layout showing (a) furnace, (6) chimney connection, (c) warm air registers (whether floor, baseboard or wall), (d) return air grilles. 3. Indicate on each warm-air leader (using symbols shown in Fig. 6): (a) whether the room to be heated is on first or second story; (6) the approximate length of leader pipe in the basement; (c) the number of right angle elbows and equivalent elbows (Table 5) required, including the elbow at the boot connection (see Fig. 2); (d) whether the register is to be located in the floor, in the baseboard, or in the wall. 4. Show the number, and proposed locations of return-air grilles and the type of return-air system (see Fig. 5). 5. From Table 6, for first story, or from Table 7 for second st-ory, select the com bination number for the warm air. system which will supply the heat required to each room, with the number of elbows and length of leader pipe previously deter mined. Then, using the combination number as found, read directly in Tables 1, 2, or. 3 the leader, stack, and register sizes required. 6. From Table 8 select the combination number for the return-air system to cor respond with the Btu per hour serviced and the type of return-air system. Then from Table 4 select the duct and grille sizes, etc., corresponding this number. 7. Select a furnace having a register delivery, in Btu per hour, equal to the total heat loss from the structure.