Alliance Laundry Systems Drying Cabinet User Manual

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Exhaust Requirements
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70304601
Individual Venting
For maximum efficiency and performance, it is preferred 
to exhaust tumbler(s) individually to the outdoors. 
IMPORTANT: At no point may the cross sectional 
area of installed venting be less than the cross 
sectional area of the exhaust outlet of the tumbler.
The exhaust duct must be designed so the static back 
pressure measured 12 inches (305 mm) from the 
exhaust outlet does not exceed the maximum 
allowable pressure specified on the installation sticker 
on the rear of the tumbler.
NOTE: Static back pressure must be measured 
with both pockets running.
The maximum allowable length venting of the same 
diameter as the exhaust thimble is 14 feet (4.3 m) and 
two 90° elbows or equivalent. If the equivalent length 
of a duct required for an installation exceeds the maximum 
allowable equivalent length, the diameter of a round duct 
must be increased by 10% for each additional 20 feet 
(6.1 m). Cross section area of a rectangular duct must 
be increased by 20% for each additional 20 feet (6.1 m). 
Refer to Table 4 to determine equivalent venting.
Example: A 12 inch (305 mm) diameter duct’s 
equivalent length of 14 feet (4.3 m) of duct and two 
90° elbows is:
Equivalent Length = 14 feet + (2) 90° elbows
= 14 feet + 14 feet + 14 feet
= 42 feet (12.8 m)
With the tumbler in operation, and both pockets 
running, airflow at any point in the duct should be at 
least 1200 feet per minute (366 meters per meter) to 
ensure that lint remains airborne. If 1200 feet per 
minute cannot be maintained, schedule monthly 
inspections and cleaning of the ductwork. 
Duct 
Diameter
Equivalent Length of 
Straight Duct
10 in. (254 mm)
12 in. (305 mm)
14 in. (355.6 mm)
16 in. (406.4 mm)
18 in. (457.2 mm)
One 90° elbow = 11.6 ft. (3.5 m)
One 90° elbow = 14 ft. (4.3 m)
One 90° elbow = 16 ft. (4.9 m)
One 90° elbow = 18.7 ft. (5.7 m)
One 90° elbow = 21 ft. (6.4 m)
Equivalent Length (feet) = 1.17 x Duct Diameter (inches)
Table 4