A.O. Smith AWH-35, Instruction Manual

Page: 21 / 48

21
TABLE 6
METAL DUCT
DUCT SIZE (INCHES)
6 8 10 12 14 16 18 20 22 24
MODEL CFM EXT (in WG)
MAXIMUM EQUIVALENT LENGTH (FEET)
AWH-35 1040 0.35 3 14 41 102 208 417
AWH-55 1650 0.35 6 17 41 90 173 308
AWH-75 2150 0.35 3 10 25 52 105 188 313
AWH-100 3200 0.35 6 14 31 59 107 180 292
AWH-115 3200 0.35 5 12 26 49 87 148 234
AWH-140 3800 0.35 4 9 18 35 64 110 170 262
AWH-170 4900 0.35 5 12 22 39 67 107 167
ELBOW SIZE (IN) 6 8 10 12 14 16 18 20 22 24
EQUIVALENT FEET
ONE 90° ELBOW
18 23 29 35 41 47 53 58 64 70
Note 1: Gradual rectangular to round transition must be used. Angle not to exceed 30°
Note 2: If elbows are used, equivalent length of elbows must be added to duct length.
TABLE 7
FLEXIBLE DUCT
DUCT SIZE (INCHES)
6 8 10 12 14 16 18 20 22 24
MODEL CFM EXT (in WG) MAXIMUM EQUIVALENT LENGTH (FEET)
AWH-35 1040 0.35 6 18 45 93 185
AWH-55 1650 0.35 3 8 18 40 77 137
AWH-75 2150 0.35 5 11 23 47 83 139
AWH-100 3200 0.35 3 6 14 26 48 80 130
AWH-115 3200 0.35 5 12 22 38 66 104
AWH-140 3800 0.35 4 8 16 29 49 76 116
AWH-170 4900 0.35 2 5 10 18 30 48 74
ELBOW SIZE (IN)
6 8 10 12 14 16 18 20 22 24
EQUIVALENT FEET
ONE 90° ELBOW
18 23 29 35 41 47 53 58 64 70
Note 1: Gradual transition must be used. Angle not to exceed 30°
Note 2: If elbows are used, equivalent length of elbows must be added to duct length.
TABLE 8
DUCT CONNECTION SIZES
UNIT SUPPLY RETURN**
VERTICAL HORIZONTAL VERTICAL HORIZONTAL
AWH-35 14 14 20.25 27
AWH-55 16 16 24 35
AWH-75 18 18 24 47
AWH-100 22 22 38 49.5
AWH-115 22 22 38 49.5
AWH-140 24 24 38 49.5
AWH-170 28 28 38 63.75
**When installing return duct to the unit, a filter access door must be included in the field fabrication.