
cannot be maintained, schedule monthly inspections and cleaning
of the ductwork.
NOTE: The maximum length of a flexible metal duct
must not exceed 7.87 ft. [2.4 m] as required to meet
UL2158, clause 7.3.2A.
Manifold Venting
While it is preferable to exhaust tumble dryers individually to the
outdoors, a main collector duct may be used if it is sized accord-
ing to
Figure 13
and
Figure 14
. This illustration indicates mini-
mum diameters, and should be increased if the collector length
exceeds 14 feet [4.3 m] and two 90° elbows. The diameter of a
round duct must be increased by 10% for each additional 20 feet
[6.1 m]. Cross sectional area of a rectangular or square duct must
be increased 20% for each additional 20 feet [6.1 m]. Refer to
Table 4
to determine equivalent ducting sizing. The collector duct
may be rectangular or square in cross section, as long as the area
is not reduced. Provisions MUST be made for lint removal and
cleaning of the collector duct.
The vent collector system 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 in the
Specifications and Dimensions Table or on the installation sticker
on the rear of tumble dryer. Static back pressure must be meas-
ured with all tumble dryers vented into the collector operating.
NOTE: Never connect a tumble dryer duct at a 90° an-
gle to the collector duct. Refer to
Figure 12
. Doing so
will cause excessive back pressure, resulting in poor
performance. Never connect two tumble dryer exhaust
ducts directly across from each other at the point of
entry to the collector duct.
With the tumble dryer in operation, airflow at any point in the
duct should be at least 1200 feet/min. [366 m/min.] to ensure that
lint remains airborne. If 1200 feet/min. [366 m/min.] cannot be
maintained, schedule monthly inspections and cleaning of the
ductwork.
T438i_SVG
Figure 12
One Manifold Assembly
TMB2403N_SVG
L
K
J
I
H
G
F
E
D
C
B
A
1
2
1.
Outlet duct diameter = largest duct diameter based on number of units
2.
45° typical
Figure 13
Exhaust Requirements
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Copyright, Alliance Laundry Systems LLC -
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39
Part No. 70458101ENR10
Summary of Contents for XT170L
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