American Dryer Corp. AD-236, Руководство по установке

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14 American Dryer Corp. 113047 - 21
2. Multiple Dryer (Common) Venting
If it is not feasible to provide a separate exhaust duct for each dryer, ducts from individual dryers may be
channeled into a “common main duct.” The individual ducts should enter the bottom or the side of the main
duct at an angle not more than 45° in the direction of the airflow. The main duct should be tapered with
the diameter increasing before each individual 8-inch (20.32 cm) duct is added.
IMPORTANT: No more than eight (8) dryers should be connected to one (1) main common duct
(refer to the illustration on the following page).
The main duct may be any shape so long as the minimum cross-sectional area is provided. The illustration
on the following page shows the minimum cross-sectional area for multiple dryer venting. These figures
must be increased in proportion as the result of whatever changes or additions are made to this ductwork
run. Two (2) examples are if ductwork length from last dryer to where duct exits the building exceeds
limits noted (20 feet [6.1 meters]) or, if ductwork runs from last dryer to where duct exits the building has
more than two (2) elbows (including outside protection).
NOTE: Refer to the illustration on the following page for examples of multiple dryer (common)
venting.
IMPORTANT: For extended ductwork runs, the cross-sectional area of the ductwork can only be
increased to an extent. Maximum proportional ductwork runs cannot exceed 20 feet
(6.1 meters) more than the original limitations of 20 feet (6.1 meters) with one (1)
elbow. When the ductwork approaches the maximum limits as noted in this manual, a
professional heating, venting, and air conditioning (HVAC) firm should be consulted
for proper venting information.
IMPORTANT: Exhaust back pressure measured by a manometer/magnehelic in the exhaust duct
must be no less than 0 and must not exceed 0.3 in WC (0.74 mb) with both baskets
(tumblers) operating.
NOTE: It is recommended that exhaust or booster fans not be used in the exhaust ductwork system
except where necessary to maintain exhaust back pressure (in the exhaust duct) between zero
and 0.3 inch water column with both baskets (tumblers) operating. Where employed, booster
fans must not activate the dryer airflow proving switch (sail switch) when the dryer is not in
operation.
The ductwork should be smooth inside with no projections from sheet metal screws or other obstructions,
which will collect lint. When adding ducts, the duct to be added should overlap the duct to which it is to be
connected. ALL ductwork joints must be taped to prevent moisture and lint from escaping into the building.
Inspection doors should be installed at strategic points in the exhaust ductwork for periodic inspection and
cleaning of lint from the ductwork.
NOTE: When the exhaust ductwork passes through a wall, ceiling, or roof made of combustible
materials, the opening must be 2-inches (5.08 cm) larger than the duct (all the way around).
The duct must be centered within this opening.