Document RjyMBjneqk6QwX8daNKN0K3mV

47.6 CHAPTER 20 1953 Guide Table 10. Pressure Drop in Duct Inches of Water per 100 Feet of Duct Length Equiva lent : Length o Total Pressure Drop in Duct (In. op Water) 0.04 0.05 0.06 0.07 0.08 0.09 0.10 0.11 0.12 6.13 6.14 0.15 0.16 0.17 0.18 0.19 35-44 45-54 55-64 65-74 75-84 85-94 95-104 105-114 115-129 130-149 150-169 '170-189- 190-214 215-239; 240-264' 265-289- 290-324 325-374 375-424 425-474 475-524 525-574 575-625 0.1C 0.0* 0.0" 0.0c 0.K 0.1c 0.0* 0.07 0.K 0.12 0.1c 0.0S 0.1* 0.14 0.12 0.1C 0.2C O.li O.i: 0.11 0.23 0.11 0.15 0.13 0.25 0.21 O.i: 0.14 0.26 0.22 0.11 0.16 0.3C 0.20.2< 0.17 0.33 0.21 0.22 0.19 0.35 0.21 0.2* 0.20 0.38 0.30 0.25 0.21 0.4C 0.32 0.27 0.23 0.43 0.34 0.28 0.24 0.45 0.3C 0.3C 0.2" 0.48 0.50 0.40 0.33 0.28 0.29 0.0s U.05 0.04 0.06 0.06 0.05 0.05 0.0* 0.07 0.06 0.05 o.os .0.10 0.06 0.0! 0.07 0.0* 0.06 0.07 00..111( 0.0! 0.08 0.13 O.i: 0.1( 0.09 0.14 0.12 O.i: 0.10 0.15 0.1* 0.1! 0.11 0.16 O.li 0.1* 0.12 0.18 0.16 O.li 0.13 0.19 0.17 0.15 0.14 0.20 0:18 0.16 0.15 0.21 0.19 0.17 0.15 0.23 0.20 0.18 0.16 0.17 0.25 0.22 0.20 0.18 0.03 0.04 0.04 0.03 0.03 0.05 0.04 0.04 0.03 0.06 0.05 0.04 0.04 0.07 0.06 0.05 0.04 0.08 0.0' 0.06 0.05 0.08 0.01 0.06 0.0b 0.09 0.0* 0.01 0.06 0.10 0.0! 0.0* 0.07 0.11 0.12 n ob 0.1! 0.0* ,0.0! 0.07 0.08 0.12 0.11 0.0! 0.08 0.13 0.11 0.10 0.09 0.14 0.12 0.11 0.09 0.15 0.13 0.11 0.10 0.16 0.11 0.17 0.14 0.13 0.11 0.02 0.01 0.03 0.03 0.02 .0.03 0.02 0.02 0;02 0.02 0.04 0.03 0.03 0.03 0.04 O.Oi 0.0* 0.03 0.05 0.04 0.04 0.03 0.05 0.05 0.04 0.04 0.06 0.05 0.04 0.04 0.06 0.05 0.05 0.04 0.07 o.oe 0.05 0.05 0.07 0.0( 0.0! 0.05 0.08 0.01 0.0( 0.05 0.08 0.07 0.06 0.06 0.09 0.08 0.07 0.06 0.09 0.08 0.07 0;i07 0:i0 0.09 0.08 0:07 0^10, 0.09! 0.08 0.07 .0.01 0.02 0.02 0.01 0.01 0.02 0.02 0.02 0.01 0.03 0.02 0.02 0.02 0.03 0.02 0.02 0.02 0.03 0.03 0.02 0.02 0.03 0.0c 0.03 0.03 0.04 0.03 0.03 0.03 0.04 0.03 0.03 0.03 0.04 0:04 0.03 0.03 0.05 0:04 0.04 0.03 0.05 0.04 0.04 0.03 0.05 0.05 0.04 0.04 0706 0.05 0.04 0.04 0.06 0.05 0,05 0.04 0.06 0.05 0.05 0.04 0.07. 0.06 0.05 0.05 0.01 0.01 0.01 0:01 0.01 0.01 0.01 0.01 0.02 0.02 0.01 0.02 0.01 0.01 0.02 0.02 0.02 0.02 00..0022 0.02 0.02 0.02 0.02 0.03 0.02 0.02 0.021 0.02 0.03 0.03 .02 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.03 0.04 0.03 0.03 0.03 0.03 0.04 0.04. 0.03 Equiva lent . Length of| Duct (Ft) 0.21 0.22 0.23 0.24 Total Pressure Drop in Duct (In. op Water) 0.25 0.26 0.27 0.28 0.29 0.30 0.32 0.34 0.36 0.38 0.40 0.45 35-44 45-54 55-64 65-74 75-84 85-94 ' 95-104 .105-114 115-129 130^149 150-169 170-189 190-214 215-239 240-264 265-289 290-324 325-374 375-424 425-474 475-524 525-574 575-625 0.53 0.35 0.30 0.55 0.44 0.37 0.32 0.58 0.46 0.39 0.33 0.60 0.48 0.40 0.34 0.63 0.50 0.42 0.36 0.65 0.62 0.43 0.37 0.68 0.54 0.45 0.39 0.70 0.56 0.47 0.40 0.73 0.58 0.48 0.42 0.75 0.60 0.50 0.43 0.80 0.64 00..8685 0.53 0.57 0.46 0.49 0.90 0.72 0.60 0.52 0.95 0.76 0.64 0.54 1.00 0.80 0.67 0.57 1.13 0.90 0.75 0.64 1.25 1.00 0.83 0.72 0.26 0.19 0.28 0.25 0.22 0.20 0.29 0.26 0.23 0.21 0.30 0.27 0.24 0.22 0.31 0.28 0.25 0.23 0.33 0.29 0.26 0.24 0.34 0.30 0.27 0.26 0.35 0.31 0.28 0.26 0.36 0.32 0.29 0.27 6.38 0.33 0.30 0.28 0.40 0.36 0.32 0.29 0.43 0.38 0.33 0.31 0.45 0.40 0:36 0.33 0.48 0.42 0.38 0.35 0.50 0.45 0.40 0.37 0.56 0.50 0.45 0.41 0.63 0.56 0.50 0.46 0:18 U. 15 00..1123 0.18 0.16 00..1124 0.19 0.16 0.14 0.13 0;20 0.17 0.15 0.13 0.21 0.18 0.16 0.14 0.22 0.19 0.16 0.15 0.23 0.19 0.17 0.15 00..2230 0.18 0.16 0.24 0.21 0.18 0.16 00..2215 0.19 0.17 0.27 0.23 0.20 0.18 0.28 00..2214 0.19 0.30 0.26 00..2203 0.32 0.27 0.24 0.21 0.33 0.29 0.25 0.22 0.38 0.32 0.28 0.25 0.47 0.360.31 0.28 . 0.11 0.09 0.08 0.08 0.11 0.10 0.09 0.08 0.12 0.10 0.09 0.08 00..1112 0.10 0.09 00..1113 0.10 0.09 00..1132 0.10 0.10 00..1142 0.11 0.10 0.14 00..1113 0.10 0.15 00..1123 0.11 0.15 000.:1i1213 0.16 0.14 00..1123 0.17 0.15 00..1124 0.18 0.16 0.15 0.13 0.19 0.17 0.15 0.14 0.20 0.18 0.16 0.15 00..2230 0.18 0.16 0.25 0.22 0.20 0.18 0.07 0.06 0.05 U.U5 0.07 0.06 0.06 0.05 0.08 0.07 0.06 0.05 0.08 0.07 0.06 0.05 0.08 0.07 0.06 0.06 0.09 0.08 0.07 0.06 0.09 0.08 0.07 0.06 0.09 0.08 0.07 0.06 0.10 0.10 0.09 0.09 0.08 0.08 0.07 .0.07 0.11 0.09 0.08 0.07 0.11 0.10 0.09 0.08 00..1120 0.09 0.08 00..1113 0.09 0.09 00..1113 0.10 0.09 0.15 00..1113 0.10 0.17 0.14 0.13 0.11 0.04 0.04 0.04| 0.04 0.04 0.04 0.05 0.04 0.04 0.05 0.04 0.04 0.05 0.05 0.04 0.05 0.05 0.04 0.05 0.05 0.05 0.06 0.05 0.05 0.06 0.05 0.05 0.06 0.06 0.05 0.06 0.06 0.05 0.07 0.07 0.00 0.07 0.07 0.06 0.08 0.07 0.06 0.08 0.07 0.07 0.09 0.08 0.08 the need for a duct to bring the warm air down from the top of the furnace, or a duct to bring the return air down to the blower inlet. Several arrangements of perimeter ducts may be used to heat slabs on ground construction, but the most common is the type having a complete loop of a continuous duct around the edge of the slab, supplied, by radial feeders extending from the furnace sub-floor plenum to the perimeter duct. A schematic cross-section of the slab construction, with the perimeter duct installed, is shown in Fig. 5. The slab should be constructed on a well-drained site where drainage is Forced Warm Air Systems , .47:7 away from the slab, and where there is no standing'water at any time of .the,year. With dab construction, a suitable porous fill and a waterproof imembrane: as a moisture barrier beneath the slab are required by the Federal Housing Administration. They are highly necessary with warm air -perimeter heating. Insulation must be placed between the. edge 'of'the slab and the foundation, and must extend completely around the slab to reduce the heat losses from the edge of the slab. Fig. 5 also shows many of the essential features of the slab and under-slab construction. COOLING METHODS A slight cooling effect may be obtained under certain conditions by. the .circulation of basement air. A more positive cooling effect may be obtained by the use of an air washer where the temperature of the city or wejl.water is;sufficiently low (55 F or lower), and where a sufficient volume, of water can be provided. Unless the temperature of the leaving water is below the FLOOR SURFACE GRAVEL PASSED OVER y." SCREEN 55# ROOFING FELT MOISTURE BARRIER WATER PROOF INSULATION BOARD 16" WIDE 2" THICK RECOMMENDED Fig. 5. Cross-section of Slab Construction Containing Perimeter Duct' . dew-point temperature of the indoor air at the time the washer is started, both the relative and absolute humidities will be somewhat increased. Coils of copper finned tubing through which cold water is pumped are available for cooling. They require less space than air washers, and have the advantage that no moisture is added to the air when the temperature of the water rises above the dew-point. Ample coil surface and fan capacity are necessary with this type of cooling. . It is thoroughly feasible to use ice or mechanical refrigeration in connec tion with a warm air system and to cool the building by this method, pro vided the building is reasonably well constructed and insulated. Windows and doors should be tight, and awnings should be supplied on the sunny side of the building. See also Chapters 30, 37 and 38. Conclusions drawn from studies11 conducted in the University of Illinois Research Residence, subject to the limitations of the test are: 1. An uninsulated building of ordinary residential type may require the equivalent cftbree tons of ice in 24 hr on days when the maximum outdoor temperature reaches 100 F, if an effective temperature of approximately 72 ET is maintained indoors. . 2. The use of awnings at all windows in east, south, and west exposures may result in savings of from 20 to 30 percent in the required cooling load.