Ducting
How to calculate the effective duct length
The overall duct length will determine the duct diameter (see the "Additional duct lengths" table). In Canada the exhaust duct must be 4" (102 mm) in diameter.
Measure the actual duct length needed to go from the dryer’s exhaust connection to the vent outlet:
1.Establish the number of elbows or bends necessary, noting the type of bend, angle and radius involved (see the "Additional duct lengths" table).
2.Add the additional duct length (as derived by using the values specified in the "Additional duct lengths" table) to the actual duct length to get the effective length.
Note:
Maximum effective duct lengths:
4" (100 mm) diameter | 66 ft (20 m) |
5" (125 mm) diameter | 131 ft (40 m) |
6" (150 mm) diameter | 328 ft (100 m) |
If using flexible metal duct the total length must not exceed 7' 10" (2.4 m).
See the "Additional duct lengths" table for more information on maximum duct lengths and number of bends.
Effective duct lengths over 66 ft (20 m) require a larger duct diameter.
Longer ducts may lead to decreases in dryer efficiency if the next larger duct diameter is not followed.
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