Document 3N92geZRjM5ze0Z4EaLmVd5b6

CHAPTER 26 1949 Guide Fig 1. Centrifugal Fan Type Unit Heater--Floor Mounted Lj T ........ TT ^-WALL*'f. 1 HEATING ELEMENT - .SUPPLY | / . JUMPERS -1 I J 14 RECIRCULATED / " ./ RETURN Fig. 2. Centrifugal Fan Type Unit Heater-Suspended Fig. 4. Propeller Fan Type''Unit Heater--Vertical Blow. Unit Heaters, Unit Ventilators, Unit Humidifiers 549 Table 2. Constants for Determining the Capacity of Unit Heaters for Various Steam Pressures and Temperatures of Entering Air (Based on Steam Pressure of t Jmg and Entering'Air Temperature of 60 P) Temperature op Entering Air SURE PSI -10 0 .10 20 30 . 40 50 60 70 80 90. 100? 0 2 5 10 Id 15 > H 20 X 30 D O' 40 * X 50 H 60 O 70 (9 75 SO 90 . 100 1.54 1.59 1.64 1.73 1.80 1.86 1.97 2.06 2.13 . 2.20 2.26 2.28 2.31 2.36 2.41 1.45. 1.50 1.55 1.64 1.71 1.77 1.87 1.96 2,04 2.09 2.16 2.18 2.21 2.26 2.31 1.37 1.41 1.46 1.55 1.61. 1.68 1.78 1.86 1.94 2.00 2.06 2.09 2:11. 2.16 2.20 1.27 1.32 1.37 1.46 1.53 1.58 1.68 1.77 1.85 1.90 1.96 1.99 2.02 2.06 2.11 1.19 1.24 1.29 1.38 1.44 1.50 1.60 1.68 1.76 1.81 1.87 1.90' 1.93 1.97 2.02 1.11 1.03 1.16 . 1.0S 1.21 1.13 1.29 1.21 1.34 1.28 1.42 1.33 1.51 1.43. 1.60 1.51 1.67 1.58 1.73 1.64 1.78 1.70 1.81 1.72 1.84 1.75 1.88 1.79 1.93 1.84 0.96 0.88 1.00 0.93 1.05 0.97 1.13 1.06 1.19 * 1.12 1.25 1.17 1.35 1.27 1.43 1.35 1.50 1.42 1.56 1.47 1.61 183 1.64 1.55 1.66 1.58 1.71 1.62 1.75 1.66 0.81 0.74 0.85 0.78 0.90 083 0.9S 0.91 1.04 0.97 1.10 1.02 1.19 1.12 1.27 1.19 1.34' 1.26 189, 1.31 1.45 1.37 1.47 1.40 1.50. 1.42 1.54 1.46 1.58 1.50 0.67 0.71' 0.7& 0.840.90 0.95 1.04 1.12 1.19 1.24 1.29 182 . 1.34 1.38 1.42 0 1.48 1.41 1.33 1.25 1.18 1.11 1.03 0.96 0.89 0.82 0.75 0.69 2 1.52 1.44 1.36 1.29 1.22 1.14 1.07 1.00 0.93 0.86 0.79 . 0.73 5 1.57 1.49 1.41 1.33 1.26 1.19 1.11 1.05 0.98 0.91 .0.84 0.77 10 1.64 1.56 1.48 1.40 1.33 1.25 l.ZS 1.11 1.04 0.97 0.90 0.84 CU 15 1.69 1.61 1.53 1.46 1.3S 1.31 1.24 1.17 .1:10 1.03 . 0.96 0.90 H- 20- 1.73 1.65 1.57 1.50 1.42 1.35 1.28 1.21 1.14 1.07 1.00 0.94 X o 30 1.80' 1.73 1.65 1.57 1.50 1.42 2.35 1,28 1.21 1.15 1.08 1.01 D -- O 40 1.86 1.79 1.71 1.64 1.56 . 1.49 1.42 1.35 1.28 1.22 1.15 1.0S 33 H 50 1.93. 1.85 1.77 1.70 1.63 1.55 1.48 1.42 1.35 1.28 1.21 185 60 1.97 .1.90. 1.82 1.75 1.67, 1.60 1.53 1.46 l:40 1.33* 1.26 1.19 OS 70 2.02 1.94 1.87 1.80 1.72 1.65 1.58 1.51 1.44 1.38 181 .184 Q 75 2.04 1.07 1.90 1.82 1.75 1.68 1.61 1.54 1.47 1.40 183 187 80 2.06 1.99 1.91 1.81 1.77 1.70 1.63 1.56 1.49 1.42 185 189 90 2.10 2.03 1.95 1.88 1.80 1.73 1.66 1.59 1.52 1.46 1.39 1.32 100 2.15 2.07 1.99 1.92 1.E5 1.77 1.70 1.63 1.56 1.49 1.43 .186 ; To determine capacity at any steam pressure and entering temperature, multiply'constant from table by rated capacity at 60 F entering air and 2 psi. When increasing steam pressure it is important to determine whether the heater is suitable for the increased pressureapplication and whether thereslilting increased outlet temperatureis satisfactory.'