Document 0L4KodkNgYMOXyL3ge1od9BYx

HEATINC VENTILATINC AIR CONDITIONING GUIDE 1944 Table 2. First Story Warm-Air Ducts* Unit No. Leader Pipe Diameter, In. " Floor Register Sizb, lit. Baseboard Size Extension 1 2 3 4 5 8 ,9 10 12 14 . 8x 10 9 x 12 10 x 12 12 x 14 14 x 16 10 x 8 12 x 8 12 x 9 13 x 11 25* 25* 35* 55* Table 3. Second Story Warm-Air Ducts--Single Wall Stacks and Fittings Unit No. Leader Pips Diameter, In. Size In. 11 8 12 9 13 9 14 10 15 12 16 12 10x33* 12 x 33* 13 x 35* 14 x 35* 12x53* 14 x 53* Floor 8x 10 8x12 8x 14 8x 14 Register Size, In. Baseboard Size 10 x 8 12 x 8 12 x 8 12 x 8 12 x 10 13 x 11 Extension 25* 25* 2 5* 23* 35* 35* . Sidewall 10x8 12x8 12x8 12x8 Table 4. Second Story Warm-Air Ducts--Double Wall Stacks and Fittings Unit No. Leader Pipe Diameter, In. Stack Size, In. Internal External 21 8 , 23*c X 10 3Hcx 105* 22 8 3 x 10 35* xl05* 23 9 2)*c x 12 33*c x 125* 24 9 3 x 12 35* x 125* Floor 8x 10 8x 10 8 x 12 8 x 12 Recistek Size, In. Baseboard Size Extension Sidewall 10x8 10x8 12x8 12x8 23* 23* 23* . 23* 10 x 8 10x8 12 x 8 12 x 8 -,,uw ii,c uueuiauons indicate a requirement for a given room greater than Unit No. 4, smaller units totalling the required capacity are recommended. bRecommended stack sizes. Tables may also be applied to 3 in. and 314 id* stack depths. 'Commercial sizes vary >4 in. from values shown. furnace, and not more than 14 in. above the floor in the case of oil or gas furnaces. In order to accomplish this the shoe is made wide. OUTLINE OF DESIGN PROCEDURE The data underlying the design procedure aregiven indetail in a circular* issued by the University of Illinois. In this procedure the design of the warm-air duct system js considered as an entire unit, so that for a given _h_e_a_t_l_o_ss the sizes of leaders, s} tacks, boots, stackheads, and registers are *Siraptified Procedure for Selecting Capacities of Duct Systems for Gravity Warm-Air Heating Plants, b19y4A2).. P. Kratz and S. Konzo {University of Illinois, Engineering Experimental Station Circular 45. Dec.. 362 i ft CHAPTER 19. GRAVITY WARM AIR FURNACE SYSTEMS Table 5. Return Air Ducts Unit No. 31 32 33 34 35 36 37 38 Duct Dla. In. Area at Shoe Con nection. Sq In. Metal Grille Sizes Choose One ABc When Joist Lining is Used*1 When Duct is Used No. of Minimum* Joists Depth, Lined In. Choose One 10 8x14 10x12 i 7 14 x 6 12 x 8 12 6x30 8x24 12x14 i 9 22 x 6 16 x 8 14 170 8x30 10x24 14x16 i 12 28 x 6 22 x 8 16 220 10x30 12x24 2 8 28 x 8 22x10 18 280 12x30 14x24 2 10 36 x 8 28x10 20 340 14x30 18x24 2 12.5 36x10 30x12 22 420 18x30 2 15.0 42x10 36x12 3 10.0 42x10 36x12 24 500 20x30 2 18.0 42x12 36x14 3 12.0 42x12 36x14 * Based on 14 in. space between joists. Use fall depth of joist except when joist depth is less than minimum depth required, when pan must be used. all correlated. Similarly in the case of return ducts, the selection specifies a complete unit consisting of return grille, return duct, and shoe connection. Recommended Standard Sizes For the purpose of simplification and standardization, selected com binations of commercial sizes of warm air pipes, return air pipes, ducts, grilles, fittings, and registers are designated as units. The unit numbers assigned and the combinations selected as standard are listed in the following tables3: Table 2--Units 1 to 5--First Story Warm Air Ducts and Registers. Table 3--Units 11 to 16--Second Story Warm Air Ducts, Single Wall Stacks, Fit tings, and Registers. Table 4--Units 21 to 24--Second Story Warm Air Ducts, Double Wall Stacks, Fittings, and Registers. Table 5--Units 31 to 38--Returns Air Ducts, Fittings, and Grilles. The selected types of boots are shown in Fig. 2. 'It is essential that free areas be maintained throughout fittings.. The selected types of return .air ducts and fittings are shown in Fig. 3. Carrying Capacity The Btu carrying capacities of the selected units of warm air and return air combinations are shown in Tables 6, 7 and 8: Table 6--Units 1 to 5--Warm Air Carrying Capacities to first story registers witli 1 to 5 elbows and with leaders 4 to 24 ft long. Table 7--Units 11 to 16 and 21 to 24--Warm Air Carrying Capacities to second story registers with 1 to 5 elbows and with leaders 4 to 24 ft long. Table 8--Units 31'to-38--Return Air Carrying Capacities for types A, B, C, D and E . return combinations. 'Standard Code Application Manual for Gravity Warm Air Heating Systems. First Edition, 1941, National Warm Air Heating and Air Conditioning Association. 363