Manifold Venting - ALLIANCE BA120E Installation Manual

Duct Diameter
18 in. [457 mm]
Equivalent Length (meter) = 1.17 x Duct Diameter (mm)
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 ft. [4.3 m] + (2) 90° elbows
= 14 ft. [4.3 m] + 14 ft. [4.3 m] + 14 ft. [4.3 m]
= 42 ft. [12.8 m]
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.
NOTE: The maximum length of a flexible metal duct
must not exceed 7.9 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 9 and Figure 10 . 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
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DO NOT COPY or TRANSMIT
Equivalent Length of
Rigid Straight Duct
One 90° elbow = 21 ft. [6.4
m]
Table 1
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 2 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 8 . 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.
33
Exhaust Requirements
T438i_SVG
Figure 8
Part No. 70532501ENR7